WO2012046280A1

WO2012046280A1 - Organic el display panel, method for manufacturing same, and organic el display device

Info

Publication number: WO2012046280A1
Application number: PCT/JP2010/006019
Authority: WO
Inventors: 哲郎近藤
Original assignee: パナソニック株式会社
Priority date: 2010-10-07
Filing date: 2010-10-07
Publication date: 2012-04-12

Abstract

In the present invention a positive electrode (105) is disposed in a state such that an end part (P₁) thereof is separated from an end part (P₂) of a bank facing an opening. A positive electrode (105) has a laminated structure comprising, from a planarizing film (104) side, a metal layer (1051) comprising silver (Ag) or a silver alloy (Ag alloy) and a transparent conductive layer (1052) comprising ITO. Of these layers, the metal layer (1051) has a thickness (t₂) of 60 to 200 nm inclusive, and the surface part thereof is a reflecting part having a predetermined reflectance. In addition, an organic functional layer (107) formed on top of the positive electrode (105) has a thickness (t₃) that is the same as or greater than thickness (t₁) of the positive electrode (105), and is formed from the top surface of the positive electrode (105) to the side surface of the end part.

Description

Organic EL display panel, manufacturing method thereof, and organic EL display device

The present invention relates to an organic EL display panel, a manufacturing method thereof, and an organic EL display device.

In recent years, research and development of organic electroluminescence (EL) display devices have been conducted. An organic EL display panel included in an organic EL display device has a configuration in which an organic EL element is provided for each pixel, and emits light by utilizing an electroluminescence phenomenon of a solid fluorescent material for each organic EL element. As an example of the prior art, the configuration of the organic EL display panel disclosed in

Patent Documents

1 and 2 will be described with reference to FIG.

As shown in FIG. 16, in the organic EL display panel according to the prior art, a TFT (Thin Film Transistor) layer 902 is formed on a substrate 901 (FIG. 16 shows only a part of the source). A passivation film 903 and a planarization film 904 are sequentially stacked thereon. An anode 905 is formed on the planarization film 904 in a state corresponding to each pixel 900. The anode 905 includes a metal layer 9051 and a transparent conductive layer 9052 that are sequentially stacked from the planarization film 904 side. The anode 905 is also embedded in a contact hole 904a opened in the planarization film 904, thereby connecting to the TFT layer 902.

A bank 906 is formed on the planarizing film 904 so as to partition the pixel 900 and the adjacent pixel 900. The bank 906 is disposed so as to cover a part of the end of the anode 905. An organic functional layer 907 is stacked on the anode 905 in the region of the pixel 900 defined by the bank 905. The organic functional layer 907 is a wet coating type layer and includes at least an organic light emitting layer. A cathode 908 is formed on the organic functional layer 907 and the bank 906, and a sealing layer 909 is stacked so as to cover the cathode 908.

Incidentally, in the organic EL display device according to the prior art shown in FIG. 16, since the bank 906 covers the end portion of the anode 905, it is difficult for current to flow through the portion, and the reduction of the light emitting region becomes a problem. Further, as shown in FIGS. 17A and 17B, due to coating unevenness in both end portions (portions indicated by arrows I and J) of the organic

functional layers

927 and 937 in the

respective pixels

920 and 930. Thickness non-uniformity may occur. Such a phenomenon causes uneven luminance of light emission, and improvement is required from the viewpoint of improving image quality.

On the other hand, in Patent Document 3, a proposal is made to solve the above-described problems by increasing the interval between the bank and the anode by narrowing the bank width. That is, by narrowing the bank width, the end portion of the anode is not covered with the bank, and by this configuration, the light emitting region can be widened and the thickness of the organic functional layer on the anode can be made uniform.

Japanese Patent Laid-Open No. 11-54286 JP 2004-192890 A JP 2005-93421 A

However, in the technique proposed in Patent Document 3, the organic functional layer is cut off at the end of the anode due to a gap between the bank and the anode, and the anode and the cathode are short-circuited. Even if no step breakage occurs, problems such as electric field concentration may occur due to the extremely thin organic functional layer. That is, as shown in FIG. 18, in the case of the configuration spacing d ₉ between the end portion P ₉₂ of the end portion P ₉₁ and the bank 906 of the anode 955, at the end of the anode 955 (the portion indicated by the arrow K) It may occur that the anode 955 and the cathode 908 are short-circuited.

As shown in FIG. 18, the anode 955 has a laminated structure of a metal layer 9551 such as a silver (Ag) layer or a silver alloy (Ag alloy) layer and an ITO (indium tin oxide) layer 9552. Since the layer 9551 is formed in the same process as the bus bar not shown, the thickness t ₉₂ is currently formed in a thick film in accordance with the bus bar. Than this, conventionally, the thickness t ₉₁ of the anode 955 has become thicker, when the thickness t ₉₃ than to form a thin organic functional layer 957a, the organic functional layer disconnection in the portion indicated by the arrow K Produce. That is, the organic functional layer 957a and the organic functional layer 957b are discontinuous from the portion indicated by the arrow K as a boundary. In this case, there arises a problem that the anode 955 and the cathode 908 are short-circuited at the stepped portion.

In order to prevent the occurrence of step breaks as described above, it is conceivable to increase the thickness of the organic functional layer. However, when such a configuration is adopted, the anode 955 and the cathode 908 The electrical resistance between the two increases. Therefore, in order to obtain a desired luminance, it is necessary to apply a higher voltage, and the deterioration of the organic light emitting layer in the organic functional layer is promoted, which may cause a problem that the lifetime is reduced. Moreover, since it is necessary to apply a higher voltage, there arises a problem that the power consumption of the organic EL display panel is increased.

The present invention has been made to solve the above-described problem. The light emitting region is wide, the thickness of the organic functional layer in the light emitting region is maintained uniform, and the organic functional layer is not broken. Therefore, it is an object of the present invention to provide a long-life organic EL display panel, a manufacturing method thereof, and an organic EL display device having excellent light emission characteristics.

The organic EL display panel according to an aspect of the present invention includes a substrate, a bank, a first electrode, an organic functional layer, and a second electrode.

The bank is formed above the substrate and defines an opening corresponding to a predetermined pixel area.

The first electrode is disposed above the substrate and includes a silver layer or a silver alloy layer, and the surface portion of the silver layer or the silver alloy layer is a reflective portion having a predetermined reflectance.

The organic functional layer is formed on the upper surface of the first electrode and includes at least an organic light emitting layer.

The second electrode is disposed above the organic functional layer, and is light that is irradiated upward from the organic functional layer and light that is irradiated downward from the organic functional layer and reflected by the reflecting portion of the first electrode. Are transparent.

In the organic EL display panel according to one aspect of the present invention, the first electrode is disposed in the opening of the bank, the end of the first electrode being spaced apart from the end of the bank facing the opening, and the silver included in the first electrode The film thickness of the layer or the silver alloy layer is a predetermined film thickness of 60 [nm] or more and 200 [nm] or less.

The organic functional layer has a thickness equal to or greater than a predetermined thickness of the first electrode, and is formed from the upper surface of the first electrode to the side surface of the end portion.

In the organic EL display panel according to one embodiment of the present invention, the film thickness of the silver (Ag) layer or the silver alloy (Ag alloy) layer (hereinafter referred to as “metal layer”) in the first electrode is 60 [nm]. The reflection part has a predetermined film thickness of 200 [nm] or less, whereby the surface portion of the metal layer of the first electrode has a predetermined reflectance with respect to the light emitted from the organic light emitting layer in the organic functional layer. It becomes. That is, when the thickness of the metal layer in the first electrode is less than 60 [nm], the amount of light reflected downward from the organic light emitting layer in the organic functional layer to the second electrode is reduced, and light emission Although the efficiency is reduced, high luminous efficiency can be obtained by setting the thickness of the metal layer in the first electrode to 60 [nm] or more.

In the organic EL display panel according to one embodiment of the present invention, the thickness of the organic functional layer is set to be equal to or larger than the predetermined thickness of the first electrode, and extends from the upper surface of the first electrode to the side surface of the end portion. A configuration in which an organic functional layer is formed is employed. For this reason, in the organic EL display panel according to one embodiment of the present invention, the thickness of the organic functional layer is reduced by adopting the thickness of the organic functional layer with respect to the first electrode and the form of forming the organic functional layer with respect to the first electrode. It is not necessary to make it thicker than necessary, and there is no problem of a decrease in life due to an increase in electrical resistance between the first electrode and the second electrode, and at the same time, the power consumption of the organic EL display panel increases. Does not occur.

Also, the organic functional layer at the end of the first electrode is not cut off or extremely thinned.

As described above, in the organic EL display panel according to one embodiment of the present invention, the light emitting region is wide, the thickness of the organic functional layer in the light emitting region is maintained uniform, and the organic functional layer is disconnected. There is no. Therefore, the organic EL display panel according to one embodiment of the present invention has a long lifetime while having excellent light emission characteristics.

1 is a schematic block configuration diagram showing a configuration of an organic EL display device 1 according to Embodiment 1. FIG. 2 is a schematic cross-sectional end view showing a partial configuration of an organic EL display panel 10. FIG. 2 is a schematic cross-sectional end view showing a partial configuration of an organic EL display panel 10. FIG. FIG. 2 is a schematic plan view showing a part of the organic EL display panel 10 extracted. 2 is a schematic cross-sectional end view showing the vicinity of an end portion of an anode 105 in an organic EL display panel 10. FIG. (A) is a schematic cross-sectional end view showing the mutual positional relationship between the anode 105 and the organic functional layer 107 in the organic EL display panel 10 according to Embodiment 1, and (b) is an organic EL according to a comparative example. FIG. 10 is a schematic cross-sectional end view showing a mutual arrangement relationship between an anode 955 and an organic functional layer 957 in a display panel. It is a characteristic view showing the relationship between the wavelength of light and the reflectance for each film thickness of the metal layer 1051. It is a characteristic view which shows the relationship between the film thickness of the metal layer 1051 for every luminescent color, and a reflectance. (A) is a schematic cross-sectional view used for defining the film thickness t ₃ when the organic functional layer 107 has a two-layer structure, and (b) shows a case where the organic functional layer 117 has a three-layer structure. it is a schematic cross-sectional view used to define the thickness t _13, (c) is a schematic sectional view used to define the thickness t232 of the charge injection layer 1271 included in the organic functional layer 127. FIGS. 4A to 4D are schematic process diagrams showing a part of the manufacturing process of the organic EL display panel 10. (A) to (c) are schematic process diagrams showing a part of the manufacturing process of the organic EL display panel 10. (A), (b) is a schematic process drawing which shows a part of manufacturing process of the organic electroluminescence display panel 10. 5 is a schematic cross-sectional end view showing a partial configuration of an organic EL display panel 30 according to Embodiment 2. FIG. FIG. 10 is a schematic plan view showing a partial configuration of an organic EL display panel 40 according to Embodiment 3. 4 is a schematic cross-sectional end view showing a partial configuration of an organic EL display panel 40. FIG. It is a schematic cross section end view which shows a partial structure of the organic EL display panel which concerns on a prior art. (A), (b) is a schematic cross section end view which shows the cross-sectional shape of the edge part of the organic

functional layers

927 and 937 used as a problem in a prior art. It is a schematic cross-sectional end view showing the end cross-sectional shape of the organic functional layer 957 in the vicinity of the end of the anode 955 which is a problem in the related art related to improvement.

[Aspect of the Invention]
The organic EL display panel according to one embodiment of the present invention includes a substrate, a bank, a first electrode, an organic functional layer, and a second electrode.

The second electrode is disposed above the organic functional layer, and is light that is irradiated upward from the organic functional layer and light that is irradiated downward from the organic functional layer and reflected by the reflecting portion of the first electrode. And transparent.

In the present specification, the peripheral edge of the first electrode is referred to as an “end”.

Here, when the bank which is an insulating layer covers the end portion of the first electrode as in the organic EL display panel according to the related art, current is applied to the end portion of the first electrode covered with the bank. It becomes difficult to flow. Therefore, a region on the first electrode that is not covered with the bank is a light emitting region. In this case, in order to increase the opening area and widen the light emitting region, it is conceivable to shift the banks to widen the region between the banks, or to reduce the bank region covering the first electrode.

In that case, the end of the first electrode may be exposed in the opening of the bank, and the end of the first electrode may not be covered with the bank. In this state, when the organic functional layer is formed at the exposed end portion of the first electrode, the organic functional layer is formed at the end portion of the first electrode when the thickness of the first electrode is larger than the thickness of the organic functional layer. There is a possibility of disconnection. As described above, when the organic functional layer is disconnected, there is a problem that the first electrode and the second electrode are directly electrically connected via the portion where the disconnection occurs and are short-circuited. .

Alternatively, even when the step does not occur as described above, when the distance between the first electrode and the second electrode becomes extremely thin at the end of the electrode, electric field concentration occurs at the end, causing light emission in the pixel. On the other hand, there arises a problem that unevenness occurs.

By the way, in order to prevent disconnection of the organic functional layer as described above, when the organic functional layer is simply increased in thickness and formed on the first electrode, the thickness between the first electrode and the second electrode is increased. Since the resistance increases, a larger voltage must be applied to obtain a desired luminance. When such a large voltage is applied to cause the organic light emitting layer to emit light, the deterioration of the organic light emitting layer is promoted and the lifetime is reduced. Moreover, since it is necessary to apply a higher voltage, there arises a problem that the power consumption of the organic EL display panel is increased.

On the other hand, when the film thickness of the first electrode is reduced without limitation, the reflectance decreases. Therefore, the amount of light reflected downward from the organic light emitting layer is reduced to the second electrode, and the amount of light directed to the second electrode is reduced, so that the light emission efficiency is lowered.

Therefore, in the organic EL display panel according to one embodiment of the present invention, the film thickness of the silver (Ag) layer or the silver alloy (Ag alloy) layer (hereinafter referred to as “metal layer”) in the first electrode is 60 [. nm] to a predetermined film thickness of 200 [nm] or less, whereby the surface portion of the metal layer of the first electrode has a predetermined reflectance with respect to light emitted from the organic light emitting layer in the organic functional layer. It becomes a reflection part. That is, when the thickness of the metal layer in the first electrode is less than 60 [nm], the amount of light reflected downward from the organic light emitting layer in the organic functional layer to the second electrode is reduced, and light emission Although the efficiency is reduced, high luminous efficiency can be obtained by setting the thickness of the metal layer in the first electrode to 60 [nm] or more.

In the organic EL display panel according to one embodiment of the present invention, the thickness of the organic functional layer is set to be equal to or larger than the predetermined thickness of the first electrode, and extends from the upper surface of the first electrode to the side surface of the end portion. A configuration in which an organic functional layer is formed is employed. For this reason, in the organic EL display panel according to one embodiment of the present invention, the thickness of the organic functional layer is reduced by adopting the thickness of the organic functional layer with respect to the first electrode and the form of forming the organic functional layer with respect to the first electrode. It is not necessary to make it thicker than necessary, there is no problem of a decrease in life due to an increase in electrical resistance between the first electrode and the second electrode, and the step of the organic functional layer at the end of the first electrode No cutting or extreme thinning. From the viewpoint of preventing disconnection of the organic functional layer, it is necessary to regulate the film thickness of the metal layer (Ag layer or Ag alloy layer) in the first electrode to 200 [nm] or less.

Further, in the organic EL display panel according to one aspect of the present invention, the end of the first electrode and the end of the bank facing the opening are separated from each other. Similar to the technique proposed in Document 3, the thickness of the organic functional layer on the first electrode can be made uniform. Therefore, the light emission characteristics are excellent.

In particular, in the short wavelength region (blue) region, when the first electrode including a silver (Ag) layer or a silver alloy (Ag alloy) layer is employed, the metal layer (Ag layer or Ag alloy layer) When the film thickness is less than 55 [nm], the reflectance becomes lower than that of the first electrode including the aluminum (Al) layer or the aluminum alloy (Al alloy) layer. Therefore, as in the organic EL display panel according to one embodiment of the present invention, the high reflectance can be maintained by defining the thickness of the metal layer (Ag layer or Ag alloy layer) to be 60 [nm] or more. it can.

In the organic display panel according to an aspect of the present invention, in the above structure, an insulating layer is disposed above the substrate, and a bank and a first electrode are disposed on the insulating layer.

When the above configuration is adopted, an organic EL display panel in which an insulating layer called a planarization film is disposed above the substrate can be realized. The insulating layer absorbs irregularities on the surface of the substrate and planarizes the surface, thereby ensuring the flatness of the bank and the first electrode when the bank and the first electrode are disposed on the insulating layer. be able to. As a result, the first electrode does not reduce the amount of light reflected downward from the organic light emitting layer to the second electrode, and prevents the amount of light directed toward the second electrode from being reduced. it can. For this reason, the fall of luminous efficiency can be prevented.

Further, when the above configuration is adopted, the thickness of the organic light emitting layer formed in the opening of the bank can be made uniform. For this reason, variations in the thickness of the organic light emitting layer can be eliminated, and variations in light emission due to variations in the thickness of the organic light emitting layer can be eliminated, thereby realizing an organic EL display panel with uniform light emission intensity. It becomes like this.

In the organic EL display panel according to one embodiment of the present invention, in the above structure, the predetermined film thickness of the silver layer or the silver alloy layer included in the first electrode is 65 [nm] or more and 120 [nm] or less. A configuration can be employed.

Thus, by setting the upper limit of the film thickness of the metal layer (Ag layer or Ag alloy layer) included in the first electrode to 120 [nm], the film is further reduced while suppressing the decrease in the reflectance of the first electrode. Since the thickness can be reduced, the organic functional layer formed on the upper surface of the first electrode can be further prevented from being broken at the end of the first electrode. Therefore, it is possible to more reliably prevent the first electrode and the second electrode from being directly electrically connected via the stepped portion of the organic functional layer and short-circuiting.

Further, when the predetermined film thickness of the silver layer or the silver alloy layer included in the first electrode is increased and the film thickness of the organic functional layer is increased in conjunction with this, the distance between the first electrode and the second electrode is increased. And the resistance between the first electrode and the second electrode increases with the interval. In this case, since the amount of current flowing between the first electrode and the second electrode decreases in inverse proportion to the resistance, the amount of light emitted by the organic light emitting layer also decreases against an increase in the interval.

In particular, the predetermined thickness of the silver layer or silver alloy layer included in the first electrode exceeds 120 [nm], and in conjunction with this, the organic functional layer also has a thickness exceeding 120 [nm]. In this case, a decrease in light emission amount due to the organic light emitting layer is not preferable because it becomes difficult to obtain a sufficient light emission amount as an organic light emitting device.

In the organic EL display panel according to an aspect of the present invention, the predetermined film thickness of the silver layer or the silver alloy layer included in the first electrode is defined in a range of 65 [nm] to 120 [nm]. . As a result, the thickness of the organic functional layer can also be set to 120 [nm] or less, so that the thickness of the organic functional layer can be further reduced, and the voltage applied between the first electrode and the second electrode is reduced. Can be made. Therefore, an organic EL display panel having a longer lifetime can be realized.

In the organic EL display panel according to an aspect of the present invention, in the above structure, the metal layer (Ag layer or Ag alloy layer) included in the first electrode has a predetermined thickness of 70 nm to 120 nm. A configuration of a film thickness can be employed.

As described above, when the thickness of the metal layer (Ag layer or Ag alloy layer) included in the first electrode is 70 [nm] or more, high reflectivity exceeding about 92 [%] is stably realized. can do. In particular, on the long wavelength region side (red), when the film thickness is set to 70 [nm] or more, the reflectivity exceeds 95 [%], and the first electrode including the Al layer or the Al alloy layer is employed. Compared to the above, it has optically superior characteristics.

As a result, an organic EL display panel having excellent optical characteristics can be realized, and the thickness of the organic functional layer can be further reduced, and the voltage applied between the first electrode and the second electrode is reduced. Can be made. Therefore, an organic EL display panel having excellent optical characteristics and a long lifetime can be realized.

In the organic EL display panel according to one embodiment of the present invention, in the above structure, the predetermined film thickness of the metal layer (Ag layer or Ag alloy layer) included in the first electrode is 70 [nm] or more and 100 [nm] or less. It is possible to adopt a configuration that

In the case of adopting the above configuration, by defining the predetermined film thickness within a range of 70 [nm] or more and 100 [nm] or less, the first electrode is made as thin as possible and the first film thickness is reduced. It is possible to ensure the same reflectance as when the electrode film thickness is greater than 100 [nm]. Therefore, an organic EL display panel having excellent optical characteristics can be realized, and the thickness of the organic functional layer can be further reduced, so that the voltage applied between the first electrode and the second electrode is reduced. Thus, an organic EL display panel having excellent optical characteristics and a long lifetime can be realized.

In the organic EL display panel according to one embodiment of the present invention, in the above structure, a transparent conductive layer is provided between the first electrode and the organic functional layer, and the film thickness of the transparent conductive layer is 5 nm or more and 130. The configuration of [nm] or less can be adopted.

In the case of adopting the above configuration, by providing a transparent conductive layer on the first electrode, the refractive index of the transparent conductive layer and its layer thickness, and the refractive index of the organic functional layer and its layer thickness are adjusted. An optical cavity structure can be realized for light emitted from the organic light emitting layer and reflected from the reflecting surface of the first electrode.

By defining the film thickness of the transparent conductive layer as 5 nm or more, the light irradiated downward from the organic functional layer reflects the distance of 5 nm that travels through the transparent conductive layer and is reflected by the reflecting portion of the first electrode. A total distance of 10 [nm] can be used for the optical cavity, with a distance of 5 [nm] traveling the transmitted light through the transparent conductive layer.

Moreover, when the film thickness of the first electrode is 65 [nm], the total film thickness of the first electrode and the transparent electrode is 200 [nm] by setting the film thickness of the transparent conductive layer to 130 [nm] or less. The organic functional layer formed on the first electrode can be prevented from being broken at the end of the first electrode, and the first electrode and the second electrode can be used to prevent the broken portion of the organic functional layer. It is possible to prevent a short circuit due to direct electrical connection.

In addition, by providing a transparent electrode, the conditions of the optical cavity of a specific wavelength can be created, so that the light extraction efficiency extracted to the outside through the second electrode can be improved, and the organic EL display with high emission luminance A panel can be realized.

In the organic EL display panel according to one embodiment of the present invention, in the above structure, the first electrode includes a silver (Ag) alloy layer, and the Ag alloy layer includes silver (Ag) and palladium ( It is possible to employ a configuration in which the alloy is composed of an alloy (APC alloy) containing Pd) and copper (Cu).

In the organic EL display panel according to an aspect of the present invention, in the above structure, the organic functional layer includes at least one of a charge injection layer or a charge transport layer formed on the first electrode, and is formed on the first electrode. The thickness of at least one of the charge injection layer or the charge transport layer is greater than or equal to a predetermined thickness of the first electrode, and at least one of the charge injection layer or the charge transport layer extends over the upper surface and the end of the first electrode. A configuration of being formed can be employed.

In the organic EL display panel according to one embodiment of the present invention, in the above structure, the organic functional layer is provided with an organic light emitting layer above at least one of the charge injection layer and the charge transport layer formed on the first electrode. It is also possible to adopt a configuration that is a layer.

In the organic EL display panel according to one aspect of the present invention, in the above structure, the organic functional layer is a layer including a charge injection layer, a charge transport layer, and the organic light emitting layer, and the charge injection layer is formed on the first electrode. It is also possible to adopt a configuration in which the thickness of the charge injection layer is equal to or greater than a predetermined thickness of the first electrode, and the charge injection layer is formed over the upper surface and end of the first electrode. .

In the organic EL display panel according to an aspect of the present invention, in the above configuration, a configuration in which an internal angle formed by the side surface of the end portion of the first electrode and the substrate is 90 [°] or less can be employed.

In the case of adopting the above configuration, the organic functional layer formed on the first electrode can be more reliably prevented from being broken at the end of the first electrode. It is possible to further reliably prevent the two electrodes from being short-circuited due to direct electrical connection via the stepped portion of the organic functional layer.

Further, in the case of adopting the above configuration, when the bank is arranged apart from the end portion of the first electrode, an unstable application region is formed in the vicinity of the bank, but below this region, the first electrode Since no exists, it becomes a non-light-emitting region. For this reason, in the light emitting region, the organic functional layer and the organic light emitting layer with little variation in coating shape are obtained, so that it is possible to reduce the luminance unevenness in the pixel and extend the lifetime.

Further, in the case of adopting the above configuration, it is possible to more reliably prevent the organic functional layer disposed above the first electrode from being broken at the end of the first electrode. Thus, occurrence of a short circuit between the first electrode and the second electrode can be reliably prevented.

Further, in the organic EL display panel according to one aspect of the present invention, since the end of the first electrode is disposed away from the end of the bank facing the opening, the organic film is applied in the vicinity of the bank. Although it may be unstable, in the organic EL display panel according to one embodiment of the present invention, since the first electrode does not exist below the region, the region does not emit light (non-light emitting region). Therefore, in the organic EL display panel according to one embodiment of the present invention, there is little variation in coating shape in the light emitting region, the organic functional layer has a uniform film state including film thickness, and luminance unevenness in the pixel is small. The effect of long life can be obtained.

In the organic EL display panel according to one aspect of the present invention, a configuration in which the predetermined pixel region is a region for each pixel and the bank defines the opening for each pixel may be employed. it can. That is, a so-called pixel bank configuration can be adopted as an example.

In the organic EL display panel according to an aspect of the present invention, the predetermined pixel region is a region in which a plurality of pixels are arranged in a line, and the bank has the openings arranged in a line. It is also possible to adopt a configuration in which each pixel is defined. That is, a so-called line bank configuration can be adopted as an example.

An organic EL display device according to one embodiment of the present invention includes any one of the above organic EL display panels. Therefore, the organic EL display device according to one embodiment of the present invention also has a long lifetime while having excellent light emission characteristics for the same reason as described above.

The method for manufacturing an organic EL display panel according to an aspect of the present invention includes the following steps.

(First step) Prepare a substrate.

(Second Step) A first electrode including a metal layer (Ag layer or Ag alloy layer) having a predetermined reflectance is formed on a substrate.

(Third step) A bank having an opening and defining a pixel region is formed above the substrate.

(Fourth Step) An organic functional layer including at least the organic light emitting layer is formed to have a film thickness equal to or larger than a predetermined film thickness of the first electrode over the upper surface and the end of the first electrode.

(5th process) The transparent 2nd electrode which permeate | transmits the light irradiated upward from the organic light emitting layer and the light irradiated from the organic light emitting layer and reflected from the reflective surface of the 1st electrode is organic. It arrange | positions above a light emitting layer.

In the method for manufacturing an organic EL display panel according to one aspect of the present invention, the first electrode is disposed in the opening of the bank with the end spaced from the end of the opening, and the metal layer included in the first electrode The film thickness of the (Ag layer or Ag alloy layer) is a predetermined film thickness of 60 [nm] or more and 200 [nm] or less, and the organic functional layer is a film thickness of a predetermined film thickness or more of the first electrode. Has characteristics.

In the method for manufacturing an organic EL display panel according to one aspect of the present invention, the predetermined thickness of the metal layer (Ag layer or Ag alloy layer) included in the first electrode is 60 nm or more and 200 nm or less. Thus, the first electrode is formed so that the surface portion thereof becomes a reflection portion having a predetermined reflectance with respect to light irradiated from the organic light emitting layer in the organic functional layer. By setting the thickness of the metal layer to 60 [nm] or more, it is possible to form the first electrode in which the reflection portion on the surface portion has high light emission efficiency.

In the method for manufacturing an organic EL display panel according to one aspect of the present invention, the thickness of the organic functional layer is set to be equal to or larger than the predetermined thickness of the first electrode, and the end portion from the upper surface of the first electrode. An organic functional layer is to be formed over the side surface. For this reason, when using the manufacturing method of the organic electroluminescence display panel which concerns on 1 aspect of this invention, the organic electroluminescence display panel manufactured is the film thickness of the organic functional layer with respect to a 1st electrode, and formation of the organic functional layer with respect to a 1st electrode By adopting the form, it is not necessary to increase the film thickness of the organic functional layer more than necessary, and there is no problem of a decrease in life due to an increase in electrical resistance between the first electrode and the second electrode, Further, the organic functional layer at the end of the first electrode is not cut off or extremely thinned. At the same time, there is no problem that the power consumption of the organic EL display panel increases.

Further, in the method for manufacturing an organic EL display panel according to one aspect of the present invention, the end of the first electrode and the end of the bank facing the opening are separated from each other. And an organic EL display panel in which the thickness of the organic functional layer on the first electrode is uniform can be manufactured. Therefore, the organic EL display panel manufactured using the method for manufacturing an organic EL display panel according to one embodiment of the present invention has excellent light emission characteristics.

As described above, in the method for manufacturing an organic EL display panel according to one embodiment of the present invention, the light emitting region is wide, the film thickness of the organic functional layer in the light emitting region is uniformly maintained, and the step of the organic functional layer is performed. The organic EL display panel produced without breakage has a long life while having excellent light emission characteristics.

In the method for manufacturing an organic EL display panel according to one embodiment of the present invention, a configuration in which an insulating layer is formed on a substrate between the first step and the second step can be employed.

In the case of adopting the above configuration, when the bank and the first electrode are arranged on the insulating layer by absorbing the unevenness of the substrate surface and planarizing the surface of the insulating layer, the bank and the first electrode Flatness can be ensured. Therefore, the first electrode can prevent the amount of light directed downward from the organic light emitting layer from being reflected to the second electrode and can prevent the amount of light directed to the second electrode from being reduced. A decrease in efficiency can be prevented.

Also, the film thickness of the organic light emitting layer formed in the opening of the bank can be made uniform. For this reason, the film thickness variation of an organic light emitting layer can be eliminated, and the light emission variation by the film thickness variation of an organic light emitting layer can be eliminated. Therefore, a method for manufacturing an organic EL display panel having uniform light emission intensity can be realized.

In the method for manufacturing an organic EL display panel according to one embodiment of the present invention, a configuration in which a transparent conductive layer is formed on the upper surface of the first electrode in the second step can be employed.

In the case of adopting the above configuration, the surface of the first electrode that is an electrode including an Ag layer or an Ag alloy layer is exposed when the opening is formed in the bank in the third step, and is oxidized by the developer in the developing step. Alternatively, oxidation by other processes can be prevented. In addition, it is possible to prevent a phenomenon (so-called hillock phenomenon) in which the surface becomes uneven without being able to withstand the thermal stress during various heating steps in the manufacturing process.

Therefore, the reflectance of the surface of the first electrode, which is an electrode including an Ag layer or an Ag alloy layer, is not reduced, the refractive index of the transparent conductive layer and its thickness, and the refractive index of the organic functional layer and its By adjusting the layer thickness, an optical cavity structure can be realized for light emitted from the organic light emitting layer and reflected by the reflecting surface of the first electrode.

As a result, it is possible to improve the light extraction efficiency of extracting the light emitted from the organic light emitting layer and reflected by the reflecting surface of the first electrode to the outside through the second electrode, and the emission luminance is high. An organic EL display panel manufacturing method can be realized.

In the fourth step, by patterning the first electrode into a predetermined shape of the first electrode by wet etching,
In the method for manufacturing an organic EL display panel according to an aspect of the present invention, in the fourth step, by forming the first electrode patterned into a predetermined shape by wet etching, the side surface of the end portion of the first electrode It is also possible to adopt a configuration in which the inner angle formed by the substrate is 90 [°] or less. Since wet etching is isotropic etching, it is preferable as a manufacturing method that the inner angle of the end portion of the first electrode be 90 [°] or less.

By this manufacturing method, it is possible to more reliably prevent the organic functional layer formed on the first electrode from being broken at the end of the first electrode, and the first electrode and the second electrode are connected to the organic functional layer. Thus, it is possible to realize a method for manufacturing an organic EL display panel that is more reliably prevented from being short-circuited by being directly electrically connected through the stepped portion.

In addition, it cannot be overemphasized that in the manufacturing method of the organic electroluminescence display panel which concerns on 1 aspect of this invention, dry etching can be used besides the said wet etching.

In the method for manufacturing an organic EL display panel according to one aspect of the present invention, the organic functional layer is formed by a wet coating method such as an inkjet method, a die coating method, or a spin coating method in the above configuration. You can also. A wet coating method such as an inkjet method, a die coating method, or a spin coating method is a method capable of forming a continuous organic functional layer in a large area. For this reason, when forming an organic functional layer using any of these methods, an organic functional layer having a uniform film thickness on the first electrode is obtained while preventing disconnection at the end of the first electrode. Suitable for forming.

In the method for manufacturing an organic EL display panel according to an aspect of the present invention, in the above configuration, the organic functional layer includes at least one of a charge injection layer or a charge transport layer formed on the first electrode, The thickness of at least one of the charge injection layer or the charge transport layer formed on the first electrode is greater than or equal to a predetermined thickness of the first electrode, and is formed from the upper surface of the first electrode to the side surface of the end portion. A configuration can also be adopted. As described above, when the organic functional layer includes at least one of the charge injection layer and the charge transport layer, the organic functional layer has excellent charge injection properties and excellent light emission characteristics. Since the charge injection layer or the charge transport layer is formed from the upper surface to the side surface of the end portion of the first electrode, the organic functional layer can be reliably prevented from being disconnected at the end portion of the first electrode. And the second electrode can be prevented from being short-circuited.

In the method for manufacturing an organic EL display panel according to an aspect of the present invention, in the above configuration, the organic functional layer is a layer in which an organic light emitting layer is provided above at least one of the charge injection layer or the charge transport layer. It is also possible to adopt the configuration.

In the method for manufacturing an organic EL display panel according to one embodiment of the present invention, in the above structure, the organic functional layer is a layer including a charge injection layer, a charge transport layer, and an organic light emitting layer, and the charge injection layer is the first. A structure in which the charge injection layer is formed on the electrode so that the thickness of the charge injection layer is greater than or equal to a predetermined thickness of the first electrode, and the charge injection layer is formed from the upper surface of the first electrode to the side surface of the end portion. Can also be adopted.

Hereinafter, embodiments for carrying out the present invention will be described using several examples.

The embodiment used in the following description is an example used to explain the configuration, operation, and effect of the present invention in an easy-to-understand manner, and the present invention is not limited to the following form other than its essential part. It is not something to receive.

[Embodiment 1]
1. Overall Configuration of Organic EL Display Device 1 Hereinafter, an organic EL display device 1 as an example of a light emitting device will be described.

The overall configuration of the organic EL display device 1 according to the present embodiment will be described with reference to FIG.

As shown in FIG. 1, the organic EL display device 1 includes an organic EL display panel 10 and a drive control unit 20 connected thereto. The organic EL display panel 10 is a panel using an electroluminescence phenomenon of an organic material, and a plurality of organic EL elements are arranged in a matrix, for example. The drive control unit 20 is composed of four drive circuits 21 to 24 and a control circuit 25.

In the actual organic EL display device 1, the arrangement of the drive control unit 20 with respect to the display panel 10 is not limited to this.

2. Configuration of Organic EL Display Panel 10 The configuration of the organic EL display panel 10 will be described with reference to FIG. 2, FIG. 3, and FIG. 2 is a cross-sectional end view of a part of the configuration of the organic EL display panel 10 taken along the Y-axis direction in FIG. 1, and shows an end surface of the CC ′ cross section in FIG. On the other hand, FIG. 3 is a cross-sectional end view of a part of the configuration of the organic EL display panel 10 cut in the X-axis direction in FIG. 1, and shows an end surface of the DD ′ cross section in FIG.

In FIG. 4, other components are not shown for easy understanding of the relationship between the anode 105 and the bank 106.

First, as shown in FIG. 2, the organic EL display panel 10 is formed with a substrate 101 as a base. On the substrate 101, a TFT (thin film transistor) layer 102, a passivation film 103, and a planarization film 104 are sequentially stacked. In FIG. 2, only the source or drain (SD electrode) which is a part of the configuration of the TFT layer 102 is illustrated.

On the planarization film 104 that is an insulating layer, a bank 106 that defines an opening corresponding to a pixel is formed. An anode 105 is formed in the pixel region defined by the bank 106 on the planarizing film 104. The anode 105 is formed by laminating a metal layer 1051 and a transparent conductive layer 1052 in this order from the planarization film 104 side. The anode 105 is also continuously formed in the contact hole 104 a opened in the planarizing film 104 and is connected to the SD electrode of the TFT layer 102.

The metal layer 1051 in the anode 105 is a layer made of silver (Ag) or a silver alloy (Ag alloy), and the transparent conductive layer 1052 is a layer made of ITO (indium tin oxide) or IZO (indium zinc oxide).

The arrangement relationship between the bank 106 and the anode 105 in the organic EL display panel 10 will be described with reference to FIG.

As shown in FIG. 4, the bank 106 in the organic EL display panel 10 is a so-called pixel bank, and an element 106a extending in the X-axis direction and an element 106b extending in the Y-axis direction are integrated. Is formed. Each opening defined by the bank 106 corresponds to one pixel, and the anode 105 is disposed in each opening. Note that the anode 105 in each pixel is connected to the SD electrode of the TFT layer 102 through a contact hole 104a.

2, the organic functional layer 107 is laminated on the anode 105. The organic functional layer 107 is a layer including at least an organic light emitting layer, and may further include a charge injection layer, a charge transport layer, a charge injection transport layer, or the like.

2, in the organic EL display panel 10 according to the present embodiment, the end of the anode 105 is in a state of being separated from the end of the bank 106 that faces the opening. In the separated portion, the organic functional layer 107 is formed in contact with the surface of the planarization film 104.

A cathode 108 is formed on the organic functional layer 107. The cathode 108 is provided in common over all the pixels in the organic EL display panel 10, and is also formed on the bank 106. A sealing layer 109 is formed on the cathode 108.

As shown in FIG. 3, in the organic EL display panel 10, the DD ′ cross section of FIG. 4 is basically the same as the CC ′ cross section shown in FIG. 2 except that the contact hole 104a is not present. It has a configuration. As shown by the arrow B portion in FIG. 3, the end portion of the anode 105 is also separated from the end portion of the bank 106 facing the opening in the DD ′ cross section. As shown in FIGS. 2 and 3, the region where the anode 105 is formed in each pixel is the light emitting region 100, and the other region including the region where the bank 106 is formed is the non-light emitting region 150.

In the organic EL display panel 10, holes are supplied from the anode 105, electrons are injected from the cathode 108, these are sent to the organic functional layer 107, and light is emitted by recombination in the organic light emitting layer. The light emitted from the organic light emitting layer of the organic functional layer 107 includes a component traveling toward the cathode 108 and a component traveling toward the anode 105. The light component directed toward the anode 105 is reflected by the surface on the upper side of the Z-axis and the surface layer portion of the metal layer 1051 of the anode 105 and travels toward the cathode 108. Thus, the surface portion of the metal layer 1051 in the anode 105 also serves as a reflection portion having a predetermined reflectance.

3. Main materials constituting organic EL display panel 10 a) Substrate 101
The substrate 101 is, for example, alkali-free glass, soda glass, non-fluorescent glass, phosphate glass, boric acid glass, quartz, acrylic resin, styrene resin, polycarbonate resin, epoxy resin, polyethylene, polyester, silicone resin. Or an insulating material such as alumina.

b) Planarization film 104
The planarization film 104 is formed using an organic compound such as polyimide, polyamide, acrylic, or silicone resin material.

c) Metal layer 1051 in the anode 105
As described above, the metal layer 1051 in the anode 105 is formed using silver (Ag) or a silver alloy (Ag alloy). In the case of the organic EL display panel 10 according to this embodiment of the top emission type, it is preferable that the surface portion has high reflectivity.

d) Transparent conductive layer 1052 in the anode 105
The transparent conductive layer 1052 in the anode 105 is formed using a transparent conductive material such as ITO (indium tin oxide) or IZO (indium zinc oxide).

e) Bank 106
The bank 106 is formed using an organic material such as resin and has an insulating property. Examples of the organic material used for forming the bank 106 include acrylic resin, polyimide resin, and novolac type phenol resin. The bank 106 preferably has organic solvent resistance. Furthermore, since the bank 106 may be subjected to an etching process, a baking process, or the like during the manufacturing process, the bank 106 should be formed of a highly resistant material that does not excessively deform or alter the process. Is preferred. In addition, the surface can be treated with fluorine to give water repellency.

When the bank 106 is formed using a lyophilic material, the difference in lyophilicity / liquid repellency between the surface of the bank 106 and the surface of the organic functional layer 107 is reduced, and the This is because it becomes difficult to selectively hold ink containing an organic substance in the opening defined by the bank 106 in order to form the organic light emitting layer.

Furthermore, as for the structure of the bank 106, not only a single layer structure as shown in FIGS. 2 and 3, but also a multilayer structure of two or more layers can be adopted. In this case, the above materials can be combined for each layer, and an inorganic material and an organic material can be used for each layer.

f) Organic functional layer 107
The organic light emitting layer included in the organic functional layer 107 has a function of emitting light by generating an excited state by injecting and recombining holes and electrons as described above. As a material used for forming the organic light emitting layer, it is necessary to use a light emitting organic material that can be formed by a wet printing method.

Specifically, for example, the oxinoid compound, perylene compound, coumarin compound, azacoumarin compound, oxazole compound, oxadiazole compound, perinone compound, pyrrolopyrrole described in Japanese Patent Publication (JP-A-5-163488) Compound, naphthalene compound, anthracene compound, fluorene compound, fluoranthene compound, tetracene compound, pyrene compound, coronene compound, quinolone compound and azaquinolone compound, pyrazoline derivative and pyrazolone derivative, rhodamine compound, chrysene compound, phenanthrene compound, cyclopentadiene compound, stilbene compound , Diphenylquinone compound, styryl compound, butadiene compound, dicyanomethylenepyran compound, dicyanomethylenethiopyran compound, fluoro Cein compound, pyrylium compound, thiapyrylium compound, serenapyrylium compound, telluropyrylium compound, aromatic ardadiene compound, oligophenylene compound, thioxanthene compound, anthracene compound, cyanine compound, acridine compound, 8-hydroxyquinoline compound metal complex, 2- It is preferably formed of a fluorescent substance such as a metal complex of a bipyridine compound, a Schiff salt and a group III metal complex, an oxine metal complex, or a rare earth complex.

Note that the organic functional layer 107 may include a charge injection layer interposed closer to the anode 105 than the organic light emitting layer. In this case, as a constituent material of the charge injection layer, for example, a conductive polymer material such as PEDOT (a mixture of polythiophene and polystyrene sulfonic acid), or a transition such as molybdenum (Mo) oxide or tungsten (W) oxide. A metal oxide or the like can be employed.

g) Cathode 108
The cathode 108 is formed using, for example, ITO (indium tin oxide) or IZO (indium zinc oxide). In the case of the top emission type organic EL display panel 10 as in the present embodiment, it is preferably formed of a light transmissive material. About light transmittance, it is preferable that the transmittance | permeability shall be 80 [%] or more.

In addition to the above, the material used for forming the cathode 108 includes, for example, a layer structure containing an alkali metal, an alkaline earth metal, or a halide thereof, or a layer containing silver in any one of the above layers. A structure in which the layers are stacked in this order can also be used. In the above, the layer containing silver may be formed of silver alone, or may be formed of a silver alloy. In order to improve the light extraction efficiency, a highly transparent refractive index adjusting layer can be provided on the silver-containing layer.

h) Sealing layer 109
The sealing layer 109 has a function of suppressing exposure of the organic light emitting layer or the like in the organic functional layer 107 to moisture or air. For example, SiN (silicon nitride), SiON (oxynitriding) It is formed using a material such as silicon.

Further, a sealing resin layer made of a resin material such as an acrylic resin or a silicone resin may be provided on a layer formed using a material such as SiN (silicon nitride) or SiON (silicon oxynitride).

In the case of the organic EL display panel 10 according to the present embodiment which is a top emission type, the sealing layer 109 is preferably formed of a light transmissive material.

4). Relationship between Anode 105, Bank 106, and Organic Functional Layer 107 The relationship between anode 105, bank 106, and organic functional layer 107 will be described with reference to FIGS.

As shown in FIG. 5, in the organic EL display panel 10 according to the present embodiment, the end portion P ₁ of the anode 105 is arranged with a distance d ₁ away from the end portion P _{2 of the} bank 106 facing the opening. Has been. This state is realized, for example, by reducing the width of the bank 106. Therefore, the organic EL display panel 10 can have a wider opening than the organic EL display panel according to the related art shown in FIG.

In addition, in the portion separated by the distance d ₁ , the organic functional layer 107 is formed on the planarizing film 104. For this reason, the anode 105 as shown in FIGS. 17 (a) and 17 (b). The problem of non-uniform thickness of the organic functional layer 107 does not occur.

The film thickness t ₂ of the metal layer 1051 in the anode 105 is set so that the reflectance for reflecting the light irradiated from the organic light emitting layer in the organic functional layer 107 toward the cathode 108 becomes a predetermined value or more. Yes. Specific thickness t ₂ is in the range of 60 [nm] or more 200 [nm] or less, desirably, the lower limit value is 65 [nm], the upper limit is 120 [nm], more preferably Has a lower limit of 70 [nm] and an upper limit of 100 [nm]. For example, when the lower limit value of the predetermined range of the film thickness t ₂ is set to 60 [nm], all of red (R), green (G), and blue (B) are exemplified as illustrated in FIG. A stable reflectance of 92 [%] or more can be obtained in the wavelength region.

In the present embodiment, the thickness t ₃ of the organic functional layer 107 is set to be equal to or greater than the thickness t _{1 of} the anode 105 and is formed from the upper surface 105a of the anode 105 to the end side surface 105b. Yes. By adopting the relationship between the film thicknesses t ₁ and t ₃ as described above, the organic functional layer 107 does not become stepped or extremely thin at the end of the anode 105 as indicated by the arrow E portion. .

The prevention of disconnection of the organic functional layer 107 will be described with reference to FIGS. 6A and 6B. FIG. 6A schematically shows the anode 105 and the organic functional layer 107 according to this embodiment, and FIG. 6B shows the anode 955 and the organic functional layer 957 according to the comparative example. Is schematically illustrated.

First, as shown in FIG. 6A, when the film thickness t ₃ of the organic functional layer 107 is set to a film thickness t ₁ or more of the anode 105 as in the present embodiment. The organic functional layer 107 is formed from the upper surface 105a of the anode 105 to the end side surface 105b. As described above, since the film thickness t ₂ of the metal layer 1051 of the anode 105 needs to be within the above numerical range in relation to the reflectance, the film thickness t ₃ of the organic functional layer 107 is It is defined by a relative relationship with the film thickness t _{1 of the} anode 105 including the film thickness t ₂ of the metal layer 1051.

Also, as shown in FIG. 6A, the internal angle θ formed by the end side surface 105b of the anode 105 and the top surfaces of the substrate 101 and the planarizing film 104 is 90 [°] or less. This also prevents the organic functional layer 107 from being disconnected at the arrow F portion.

As described above, the organic functional layer 107 does not break off at the end of the anode 105 as indicated by the arrow F in FIG.

Next, as shown in FIG. 6B, in the comparative example, the film thickness t ₉₃ of the organic functional layer 957 on the anode 955 has a smaller relationship than the film thickness t _{91 of the} anode 955. In the prior art, the anode 955 is formed in the same process as the bus bar (not shown) including the metal layer 9551, resulting in the film thickness t ₉₂ of the metal layer 9551 and the film thickness t of the anode 955. ₉₁ is thicker. Therefore, as shown in FIG. 6B, the organic functional layer 957 may break off at the arrow G portion (the end of the anode 955). Then, the organic functional layer 957 is disconnected, and the organic functional layer 957a on the upper surface 955a of the anode 955 and the organic functional layer 957b covering the end side surface 955b of the anode 955 are not continuous, and the transparent conductive layer of the anode 955 9552 is short-circuited with the cathode (not shown in FIG. 6B) at the arrow G portion.

5. Main effects of organic EL display panel 10 and organic EL display device 1 including the same In organic EL display panel 10 according to the present embodiment, metal layer 1051 (aluminum layer or aluminum alloy layer) of anode 105 serving as the first electrode. referring to a film thickness t ₂ (Figure 5) a.), and 40 [nm] or more to a predetermined thickness, thereby, the surface portion of the metal layer 1051 of the anode 105, the organic light-emitting layer in the organic functional layer 107 It becomes a reflection part which has predetermined | prescribed reflectance with respect to the light irradiated from. That is, when the thickness t ₂ of the metal layer 1051 in the anode 105 is less than 40 [nm], the amount of light reflected from the organic light emitting layer in the organic functional layer 107 to the cathode 108 side decreases, Although the light emission efficiency is reduced, high light emission efficiency can be obtained by setting the film thickness t ₂ of the metal layer 1051 in the anode 105 to 40 [nm] or more as in this embodiment.

In the organic EL display panel 10 according to the present embodiment, the thickness t ₃ of the organic functional layer 107 is set to be equal to or larger than the thickness t _{1 of the} anode 105 (see FIG. 5 and the like), and the upper surface of the anode 105 A configuration in which the organic functional layer 107 is formed from 105a to the end side surface 105b is employed (see FIG. 6A). For this reason, in the organic EL display panel 10, the film thickness t ₃ of the organic functional layer 107 with respect to the anode 105 and the above-described formation form of the organic functional layer 107 with respect to the anode 105 are employed. It is not necessary to increase the thickness t ₃ more than necessary, and there is no problem of a decrease in life due to an increase in electrical resistance between the anode 105 and the cathode 108, and the organic functional layer 107 at the end of the anode 105 is not affected. There will be no disconnection or extreme thinning (see FIGS. 5 and 6A). In addition, the film thickness t ₂ of the metal layer 1051 in the anode 105 can be reduced as the film thickness t ₁ of the anode 105 is reduced to prevent the step breakage, and specifically, 200 [nm] or less. The thickness may be preferably 120 [nm] or less, and more preferably 100 [nm] or less.

As shown in FIGS. 2, 3 and 5, in the organic EL display panel 10, the end portion P ₁ of the anode 105 and the end portion P _{2 of the} bank 106 facing the opening are separated from each other. Therefore, the light emitting region can be widened and the thickness of the organic functional layer 107 on the anode 105 can be made uniform. Therefore, the light emission characteristics are excellent.

As described above, in the organic EL display panel 10 according to the present embodiment and the organic EL display device 1 including the same, the light emitting region is wide, and the film thickness t ₃ of the organic functional layer 107 in the light emitting region is kept uniform. In addition, the organic functional layer 107 is not broken. Therefore, the organic EL display panel 10 and the organic EL display device 1 including the same have a long life while having excellent light emission characteristics.

6). The optimum range of the film thickness t ₂ of the metal layer 1051 in the anode 105 The examination results of the optimum range of the film thickness t ₂ of the metal layer 1051 in the anode 105 will be described with reference to FIGS. In FIG. 7, the horizontal axis represents the wavelength of the measurement light of the spectrophotometer used when measuring the reflectance of the metal layer 1051, and the vertical axis represents the reflectance of the metal layer 1051. FIG. 8 is a diagram illustrating the relationship between the measured thickness of the metal layer 1051 and the reflectance at each thickness with respect to the measurement data of FIG. The horizontal axis in FIG. 8 is the film thickness of the metal layer 1051, and the vertical axis is the reflectance of the metal layer 1051. In FIG. 8, measurement data for an anode containing an Al alloy is also shown as a reference example.

As shown in FIG. 7, in each sample having a metal layer thickness of 60 [nm] to 150 [nm], the reflectance is approximately 90 [%] in the wavelength range of 460 [nm] to 600 [nm]. That's it.

On the other hand, in the sample having a metal layer thickness of 30 [nm] to 50 [nm], the reflectance is lower than 90 [%] in the wavelength region of 475 [nm] or less.

Next, as shown in FIG. 8, red (R: the horizontal axis in FIG. 7 is λ = 600 [nm]), green (G: FIG. In all the wavelength ranges of λ = 530 [nm]) and blue (B: λ = 460 [nm] in FIG. 7), the reflectance was 91 [%] or more. In the range where the thickness of the metal layer is 65 [nm] or more, the reflectance is 92 [%] or more for the blue (B) light on the shortest wavelength range side, and the thickness is 70 [nm]. In the above range, the reflectance is about 92 [%] to about 97 [%], and it can be seen that the influence on the reflectance is small even if the thickness is increased further.

Further, as shown in FIG. 8, for the blue light (B: λ = 460 [nm]) on the short wavelength region side, the film thickness is 55 [relative to the reference sample containing an Al alloy as the metal layer. The reflectance value is reversed at [nm]. From this, when considering the viewpoint of material cost, it is necessary for securing the reflectance that the film thickness of the metal layer made of Ag alloy (APC) is at least 60 [nm] or more.

Note that the upper limit of the thickness t ₂ of the metal layer 1051 of the anode 105 is not particularly required from the viewpoint of reflectivity as described above, but the organic functional layer 107 is disconnected as described above. In consideration of reducing the film thickness t _{2 of the} anode 105 from the viewpoint of prevention, it is 200 [nm] or less, preferably 120 [nm] or less, and more preferably 100 [nm] or less.

Accordingly, the range of the film thickness t ₂ of the metal layer 1051 in the anode 105 is 60 [nm] or more and 200 [nm] or less, preferably 65 [nm] or more and 120 [nm] or less, or 70 [nm] or more and 120. [nm] or less, and more desirably 70 [nm] or more and 100 [nm] or less, or 50 [nm] or more and 100 [nm] or less.

In this experiment, APC (alloy consisting of Ag, Pd, and Cu), which is a kind of Ag alloy, was used as the metal layer, but the same result was obtained for other Ag alloys and further Ag. I have confirmed that.

7. In the above description, the organic functional layer 107 includes at least the organic light emitting layer. The definition including variations will be described with reference to FIG.

(1) First, as shown in FIG. 9A, the organic functional layer 107 can be a stacked structure of a charge injection layer 1071 and an organic light emitting layer 1072. In this case, the charge injection layer 1071 is laminated on the transparent conductive layer 1052 in the anode 105, and the organic light emitting layer 1072 is laminated thereon.

When this configuration is adopted, the “film thickness t ₃ of the organic functional layer 107” means the thickness obtained by adding the film thickness t ₃₂ of the charge injection layer 1071 and the film thickness t ₃₁ of the organic light emitting layer 1072. It becomes.

(2) Next, as shown in FIG. 9B, the organic functional layer 117 may be a three-layer structure including a charge injection layer 1171, an organic light emitting layer 1172, and an electron transport layer 1173. In this case, the “film thickness t ₁₃ of the organic functional layer 117” in comparison with the film thickness t _{1 of the} anode 105 is the sum of the film thickness t ₁₃₂ of the charge injection layer 1171 and the film thickness t ₁₃₁ of the organic light emitting layer 1172. In the comparison with the thickness t _{1 of the} anode 105, the thickness t ₁₃₃ of the electron transport layer 1173 is not included in the comparison.

(3) Next, as shown in FIG. 9C, the organic functional layer 127 may be a laminated structure having a three-layer structure including a charge injection layer 1271, a charge transport layer 1274, and an organic light emitting layer 1272. In this case, the “film thickness t ₂₃ of the organic functional layer 127” in comparison with the film thickness t _{1 of the} anode 105 means the film thickness t ₂₃₂ of the charge injection layer 1271, the film thickness t ₂₃₄ of the charge transport layer 1274, and organic light emission. a thickness obtained by adding the thickness t ₂₃₁ of the layer 1172.

When an electron transport layer or the like is interposed on the organic light emitting layer 1272 in FIG. 9C, the film thickness of the electron transport layer is compared with the film thickness t _{1 of the} anode 105 as described above. Shall not be included.

8). Manufacturing Method of Organic EL Display Panel 10 A manufacturing method of the organic EL display panel 10 will be described with reference to FIGS. 10 to 12 are sectional end views in main processes.

As shown in FIG. 10A, a substrate 101 is prepared.

Next, the TFT layer 102 and the passivation film 103 are formed on the main surface 101a of the substrate 101 (see FIG. 10B). In FIG. 10B as well, only the SD electrode is shown for the TFT layer 102 as described above.

Next, a planarizing film 104 which is an insulating layer is formed on the main surface 103a of the passivation film 103 above the substrate 101. As shown in FIG. 10C, for the planarizing film 104, a contact hole 104a is formed in a portion corresponding to the SD electrode of the TFT layer 102, and the passivation film 103 in the portion is also housed. The surface of the SD electrode of the TFT layer 102 is exposed at the bottom.

Next, a film for forming the metal layer 1051 and a film for forming the transparent conductive layer 1052 are sequentially stacked on the main surface 104b of the planarizing film 104. Both films are also formed on the side wall surrounding the contact hole 104a. Then, this is patterned by photolithography and etching to form the anode 105 that is a stacked structure of the metal layer 1051 and the transparent conductive layer 1052 (see FIG. 10D). Here, either dry etching or wet etching can be employed for patterning, but in particular, when wet etching is employed, the wet etching is isotropic etching, so Since the inner angle of the end portion can be 90 [°] or less, it is preferable.

Next, a film for forming the bank 106 is formed by sputtering on the main surface of the planarizing film 104 exposed without forming the anode 105. Then, a bank 106 that defines an opening corresponding to the pixel region is formed by photolithography and wet etching (see FIG. 11A). As shown in FIG. 11A, the end of the bank 106 facing the opening is formed with a distance d ₁ from the end of the anode 105.

Next, the ink 1070 for forming the organic functional layer 107 is applied to the opening defined by the bank 106 including the main surface 105a of the anode 105 (see FIG. 11B). At this time, the ink 1070 does not continue between adjacent openings due to the liquid repellency of the surface of the bank 106.

Next, the organic functional layer 107 is formed in the opening defined by the bank 106 by drying the ink 1070 (see FIG. 11C). In addition, when the organic functional layer 107 adopts a two-layer structure or a structure of three or more layers as shown in FIGS. 9A to 9C, ink application and drying for forming each layer are performed. Will be executed repeatedly.

Next, the cathode 108 is formed on the entire region including the main surface 107a of the organic functional layer 107 and the surface of the bank 106 (see FIG. 12A). Here, the cathode 108 can be formed by a sputtering method or the like.

Next, a sealing layer 109 is formed on the surface 108a of the cathode 108 (see FIG. 12B).

[Embodiment 2]
The configuration of the organic EL display panel 30 according to the second embodiment will be described with reference to FIG. 13 with a focus on differences from the first embodiment. FIG. 13 corresponds to the sectional end view shown in FIG. 2 in the first embodiment.

As shown in FIG. 13, in the organic EL display panel 30 according to the present embodiment, the organic EL display according to the first embodiment is that the anode 305 has a single layer structure of a metal layer (Ag layer or Ag alloy layer). Different from the panel 10. Also in the organic EL display panel 30, the end of the anode 305 is in a state of being separated from the end of the bank 106 facing the opening, the region where the anode 305 is formed is the light emitting region 300, and the other regions are This is a non-light emitting region 350.

Also in the organic EL display panel 30 according to the present embodiment, the film thickness of the anode 305 is set in the range of 60 [nm] or more and 200 [nm] or less, and the film thickness of the organic functional layer 107 is the film of the anode 305. It is thicker than the thickness. The organic functional layer 107 is formed from the upper surface of the anode 305 to the end side surface.

As described above, the organic EL display panel 30 according to the present embodiment and the organic EL display device including the same have the same effects as the organic EL display panel 10 and the organic EL display device 1 described above.

[Embodiment 3]
The configuration of the organic EL display panel 40 according to the third embodiment will be described with reference to FIGS. 14 and 15, focusing on the differences from the first embodiment. 14 corresponds to the plan view shown in FIG. 4 in the first embodiment, and FIG. 15 corresponds to the sectional end view shown in FIG.

As shown in FIG. 14, the organic EL display panel 40 according to the present embodiment is characterized in that the bank 406 has a so-called line bank structure. That is, as shown in FIG. 14, the bank 406 is composed of a plurality of elements extending in the Y-axis direction. The plurality of elements may be continuous with each other at the end, or conversely, each may be in a separated state.

FIG. 15 is a schematic cross-sectional end view showing a part of the organic EL display panel 40 in FIG. As shown in FIG. 15, since the organic EL display panel 40 employs a bank 406 (see FIG. 14) having a line bank structure, the bank 406 is not interposed between adjacent pixels in the Y-axis direction.

As shown in FIG. 15, also in this embodiment, the organic functional layer 407 is formed from the upper surface to the end side surface of the anode 105, and the cathode 408 and the sealing layer 409 are sequentially stacked thereon. . Therefore, also in the organic EL display panel 40, the region where the anode 105 is formed is the light emitting region 400, and the other region is the non-light emitting region 450.

For the organic EL display panel 40, the cross-sectional structure in the X-axis direction of FIG. 14 is not shown, but the structure is the same as that of the first embodiment. That is, in the X-axis direction, the end of the anode 105 is in a state of being separated from the end of the bank 406 facing the opening. Also in this embodiment, the thickness of the metal layer 1051 in the anode 105 is set in a range of 60 [nm] or more and 200 [nm] or less, and the thickness of the organic functional layer 407 is that of the anode 105. It is thicker than the film thickness.

As described above, the organic EL display panel 40 and the organic EL display device including the same according to the present embodiment have the same effects as those of the first embodiment.

[Other matters]
In the first, second, and third embodiments, the

anodes

105 and 305 are disposed below the organic

functional layers

107, 117, 127, and 407 in the Z-axis direction, that is, on the substrate 101 side. Although the

cathodes

108 and 408 are arranged above, the arrangement relationship between the anode and the cathode can be reversed upside down. In this case, in the organic functional layer, an electron injection layer or an electron transport layer is disposed in a region on the substrate 101 side with respect to the organic light emitting layer. In this case, the "film thickness of the organic functional layer" The film thickness up to the level including the organic light emitting layer is defined by integrating from the substrate 101 side.

Further, in FIGS. 1 to 15 used in the description of the first, second, and third embodiments, the sizes of the respective parts are not shown with strict relative values. Appropriate changes can be made upon application. Even in this case, it is necessary to define the thickness of the metal layer in the anode within the above range and to make the thickness of the organic functional layer larger than the thickness of the anode.

The present invention is useful for realizing a long-life organic EL display panel and an organic EL display device having excellent light emission characteristics.

1.

Organic EL display

10, 30, 40. Organic EL display panel 20. Drive control unit 21-24. Drive circuit 25.

Control circuit

100, 300, 400. Light emitting area 101. Substrate 102. TFT layer 103. Passivation film 104. Planarization film 105,305. Anode 106,406. Bank 107,117,127,407. Organic functional layer 108,408. Cathode 109,409.

Sealing layer

150, 350, 450. Non-light emitting area 1051. Metal layer 1052. Transparent conductive layer 1070.

Ink

1071, 1171, 1271. Charge injection layers 1072, 1172, 1272. Organic light emitting layer 1173. Electron transport layer 1274. Charge transport layer

Claims

A substrate,
A bank formed above the substrate and defining an opening corresponding to a predetermined pixel region;
A first electrode disposed above the substrate and including a silver layer or a silver alloy layer, wherein the surface portion of the silver layer or the silver alloy layer is a reflective portion having a predetermined reflectance;
An organic functional layer formed on an upper surface of the first electrode and including at least an organic light emitting layer;
Light that is disposed above the organic functional layer and is irradiated upward from the organic functional layer, and light that is irradiated downward from the organic functional layer and reflected by the reflecting portion of the first electrode; A second electrode that passes through,
Including
The first electrode is disposed in the opening of the bank, the end of the first electrode being spaced apart from the end of the bank facing the opening,
The film thickness of the silver layer or silver alloy layer included in the first electrode is a predetermined film thickness of 60 nm or more and 200 nm or less,
The organic functional layer has a thickness equal to or greater than a predetermined thickness of the first electrode, and is formed from the upper surface of the first electrode to the side surface of the end portion.
Organic EL display panel.
An insulating layer is disposed above the substrate;
The bank and the first electrode are disposed on the insulating layer;
The organic EL display panel according to claim 1.
The predetermined film thickness of the silver layer or silver alloy layer included in the first electrode is 65 nm or more and 120 nm or less,
The organic EL display panel according to claim 1 or 2.
The film thickness of the silver layer or silver alloy layer included in the first electrode is a predetermined film thickness of 70 nm or more and 120 nm or less,
The organic EL display panel according to claim 1 or 2.
The predetermined film thickness of the silver layer or silver alloy layer included in the first electrode is 70 nm or more and 100 nm or less.
The organic EL display panel according to claim 1 or 2.
A transparent conductive layer is provided between the first electrode and the organic functional layer,
The film thickness of the transparent conductive layer is 5 nm or more and 130 nm or less,
The organic EL display panel according to any one of claims 1 to 5.
The first electrode includes a silver alloy layer,
The silver alloy layer is composed of an alloy containing silver and palladium and copper,
The organic EL display panel according to claim 1.
The organic functional layer includes at least one of a charge injection layer or a charge transport layer formed on the first electrode,
At least one of the charge injection layer or the charge transport layer formed on the first electrode has a film thickness equal to or greater than a predetermined film thickness of the first electrode, and the upper surface and edges of the first electrode. Formed over the part,
The organic EL display panel according to claim 1.
The organic functional layer is a layer in which the organic light emitting layer is provided above at least one of the charge injection layer or the charge transport layer formed on the first electrode.
The organic EL display panel according to claim 8.
The organic functional layer is a layer including a charge injection layer, a charge transport layer, and the organic light emitting layer,
The charge injection layer is formed on the first electrode;
The charge injection layer has a film thickness equal to or greater than a predetermined film thickness of the first electrode, and is formed over the upper surface and the end of the first electrode.
The organic EL display panel according to claim 1.
The internal angle formed by the side surface of the end portion of the first electrode and the substrate is 90 degrees or less.
The organic EL display panel according to any one of claims 1 to 10.
An organic EL display device comprising the organic EL display panel according to any one of claims 1 to 11.
A first step of preparing a substrate;
Forming a first electrode including a silver layer or a silver alloy layer having a predetermined reflectance on the substrate;
A third step of forming a bank having an opening and defining a pixel region above the substrate;
A fourth step of forming an organic functional layer including at least an organic light emitting layer over the upper surface and the end of the first electrode in a film thickness equal to or greater than a predetermined film thickness of the first electrode;
A transparent second electrode that transmits light emitted upward from the organic light emitting layer and light emitted from the organic light emitting layer and reflected from the reflecting surface of the first electrode transmits the organic light emission. A fifth step of placing above the layer;
Including
The first electrode is disposed in the opening of the bank with the end spaced from the end of the opening, and the thickness of the silver layer or silver alloy layer included in the first electrode is 60 nm or more and 200 nm or less. The organic functional layer is a film thickness equal to or greater than a predetermined film thickness of the first electrode.
Manufacturing method of organic EL display panel.
A step of forming an insulating layer on the substrate between the first step and the second step;
The manufacturing method of the organic electroluminescent display panel of Claim 13.
In the second step, a transparent conductive layer is formed on the upper surface of the first electrode.
The manufacturing method of the organic electroluminescent display panel of Claim 13 or Claim 14.
In the fourth step, by patterning the first electrode into a predetermined shape of the first electrode by wet etching,
Forming an internal angle formed by the side surface of the end portion of the first electrode and the substrate to be 90 degrees or less;
The method for manufacturing an organic EL display panel according to claim 13.
The organic functional layer is formed using a wet coating method of any one of an inkjet method, a die coating method, and a spin coating method.
The method for producing an organic EL display panel according to any one of claims 13 to 16.
The organic functional layer includes at least one of a charge injection layer or a charge transport layer formed on the first electrode,
At least one of the charge injection layer or the charge transport layer formed on the first electrode has a film thickness equal to or greater than a predetermined film thickness of the first electrode, and the upper surface and edges of the first electrode. Formed over the part,
The manufacturing method of the organic electroluminescent display panel of any one of Claim 13 thru | or 17.
The organic functional layer is a layer in which the organic light emitting layer is provided above at least one of the charge injection layer or the charge transport layer.
The manufacturing method of the organic electroluminescent display panel of Claim 18.
The organic functional layer is a layer including a charge injection layer, a charge transport layer, and the organic light emitting layer,
The charge injection layer is formed on the first electrode;
The charge injection layer has a film thickness equal to or greater than a predetermined film thickness of the first electrode, and is formed over the upper surface and the end of the first electrode.
The manufacturing method of the organic electroluminescent display panel of any one of Claim 13 thru | or 17.