JP6893020B2 - Manufacturing method of organic EL display panel and organic EL display panel - Google Patents

Description

The present disclosure relates to an organic EL display panel using an organic EL (Electro Luminescence) element utilizing an electroluminescent phenomenon of an organic material, and a method for manufacturing the same.

In recent years, as a display panel used in a display device such as a digital television, an organic EL display panel in which a plurality of organic EL elements are arranged in a matrix on a substrate has been put into practical use.
In the organic EL display panel, the light emitting layer of each organic EL element and the adjacent organic EL element are generally separated by an insulating layer made of an insulating material. In the organic EL display panel for color display, the organic EL element forms sub-pixels that emit light in each RGB color, and adjacent RGB sub-pixels are combined to form a unit pixel in color display.

The organic EL element has a basic structure in which a light emitting layer containing an organic light emitting material is arranged between a pair of electrodes, and a hole is injected into the light emitting layer by applying a voltage between the pair of electrode pairs during driving. It emits light as it recombines with an electron.
The top emission type organic EL element has an element structure in which a pixel electrode, an organic layer (including a light emitting layer), and a common electrode layer are sequentially provided on a substrate. The light from the light emitting layer is reflected by the pixel electrode made of the light-reflecting material and is emitted upward from the common electrode layer made of the light-transmitting material.

The above-mentioned common electrode layer is often formed over the entire surface of the substrate, and when the electric resistance of the common electrode layer is large, the current is not sufficiently supplied due to the voltage drop in the portion far from the feeding portion, and the luminous efficiency is lowered. Due to this, uneven brightness may occur.
Therefore, a method of providing an auxiliary electrode for lowering the resistance of the common electrode layer has been proposed (for example, Patent Document 1). According to Patent Document 1, the auxiliary electrode layer is formed in the same layer as the pixel electrode, and the auxiliary electrode layer is electrically insulated from the pixel electrode and electrically connected to the common electrode layer.

JP-A-2002-318556 Japanese Unexamined Patent Publication No. 5-163488

However, when a metal such as aluminum, copper, or silver is used for the auxiliary electrode layer, an oxide film is formed on the surface of the auxiliary electrode layer, and the formed oxide film causes an electric resistance between the auxiliary electrode layer and the common electrode layer. There is a problem that it becomes high.
The present disclosure solves the above problems, reduces the electrical resistance in the electrical connection between the common electrode layer and the auxiliary electrode layer, improves the luminous efficiency, and suppresses the uneven brightness of the organic EL display panel and the organic. An object of the present invention is to provide a manufacturing method suitable for manufacturing an EL display panel.

In order to achieve this object, in the organic EL display panel according to one aspect of the present disclosure, a plurality of pixel electrodes are arranged in a matrix on a substrate, and a light emitting layer containing an organic light emitting material is arranged on each pixel electrode. An organic EL display panel comprising a substrate, a plurality of pixel electrodes arranged in a matrix above the substrate, and within at least one of the gaps between adjacent pixel electrodes above the substrate. The first power feeding auxiliary electrode layer extending in the column or row direction and the first feeding auxiliary electrode layer extending in the same direction as the first feeding auxiliary electrode layer were arranged in a part of the region on the first feeding auxiliary electrode layer. The second power feeding auxiliary electrode layer, the plurality of light emitting layers arranged on the plurality of pixel electrodes, the upper surface above the plurality of light emitting layers, the upper surface of the first power feeding auxiliary electrode layer excluding the partial region, and the said. The first feeding auxiliary electrode layer includes a common electrode layer which is continuously arranged so as to cover the upper surface of the second feeding auxiliary electrode layer, and the first feeding auxiliary electrode layer contains a first metal as a main component and the second feeding auxiliary electrode. The layer contains a second metal different from the first metal as a main component, and the resistance of the surface layer of the second feeding auxiliary electrode layer is higher than the resistance of the surface layer of the first feeding auxiliary electrode layer. And.

The organic EL display panel according to one aspect of the present disclosure can reduce the electrical resistance in the electrical connection between the common electrode layer and the auxiliary electrode layer, improve the luminous efficiency, and suppress the uneven brightness.

It is a schematic block diagram which shows the circuit structure of the organic EL display device 1 which concerns on embodiment. It is a schematic circuit diagram which shows the circuit structure in each sub-pixel 100se of the organic EL display panel 10 used for organic EL display apparatus 1. It is a schematic plan view which shows a part of an organic EL display panel 10. It is a schematic cross-sectional view cut by A1-A1 in FIG. It is an enlarged view around the 2nd auxiliary electrode layer 200 shown in FIG. (A) and (b) show the state in each step in the manufacture of the organic EL display panel 10. It is a schematic cross-sectional view cut by A1-A1 in FIG. (C) and (d) show the state in each step in the manufacture of the organic EL display panel 10. It is a schematic cross-sectional view cut by A2-A2 in FIG. (A) to (d) show the states in each step in the manufacture of the organic EL display panel 10. It is a schematic cross-sectional view cut by A1-A1 in FIG. (A) to (d) show the states in each step in the manufacture of the organic EL display panel 10. It is a schematic cross-sectional view cut by A1-A1 in FIG. (A) to (g) show the states in each step in the manufacture of the organic EL display panel 10. It is a schematic cross-sectional view cut by A1-A1 in FIG. (A) to (b) show the state in each step in the manufacture of the organic EL display panel 10. It is a schematic cross-sectional view cut by A1-A1 in FIG. It is a schematic diagram which shows the sputtering apparatus 600 used for manufacturing a common electrode layer 125.

<< Outline of the mode for carrying out the present invention >>
The organic EL display panel according to the aspect of the present disclosure is an organic EL display panel in which a plurality of pixel electrodes are arranged in a matrix on a substrate, and a light emitting layer containing an organic light emitting material is arranged on each pixel electrode. , A substrate, a plurality of pixel electrodes arranged in a matrix above the substrate, and extending in a column or row direction in at least one of the gaps between adjacent pixel electrodes above the substrate. The first power feeding auxiliary electrode layer arranged in the same direction, and the second feeding auxiliary electrode layer extending in the same direction as the first power feeding auxiliary electrode layer in a part of the region on the first power feeding auxiliary electrode layer. A plurality of light emitting layers arranged on the plurality of pixel electrodes, above the plurality of light emitting layers, on the upper surface of the first power feeding auxiliary electrode layer excluding the partial region, and on the second feeding auxiliary electrode layer. The first feeding auxiliary electrode layer includes a first metal as a main component, and the second feeding auxiliary electrode layer includes the common electrode layer which is continuously arranged so as to cover the upper surface, and the first feeding auxiliary electrode layer is the first metal. The resistance of the surface layer of the second feeding auxiliary electrode layer is higher than the resistance of the surface layer of the first feeding auxiliary electrode layer.

With this configuration, it is possible to reduce the electrical resistance in the electrical connection between the common electrode layer and the auxiliary electrode layer, improve the luminous efficiency, and suppress the uneven brightness.
Here, it may be assumed that a metal oxide film is formed on the surface layer of the second power feeding auxiliary electrode layer.
Further, the sheet resistance of the first feeding auxiliary electrode layer may be higher than the sheet resistance of the second feeding auxiliary electrode layer.

Further, the contact resistance between the first feeding auxiliary electrode layer and the common electrode layer may be lower than the contact resistance between the second feeding auxiliary electrode layer and the common electrode layer.
Further, the surface area of the first feeding auxiliary electrode layer may be larger than the surface area of the second feeding auxiliary electrode layer.
Further, the first metal may be tungsten or molybdenum, and the second metal may be aluminum.

Further, in the method for manufacturing an organic EL display panel according to the aspect of the present disclosure, a plurality of pixel electrodes are arranged in a matrix on a substrate, and a light emitting layer containing an organic light emitting material is arranged on each pixel electrode. A method of manufacturing a display panel, in which a step of forming a plurality of pixel electrodes arranged in a matrix above the substrate by a vapor phase growth method and a gap between adjacent pixel electrodes above the substrate. A step of forming a first feeding auxiliary electrode layer extending in a column or row direction in at least one gap of the above by a vapor phase growth method, and the first in a partial region on the first feeding auxiliary electrode layer. 1 A step of forming a second power feeding auxiliary electrode layer stretched in the same direction as the feeding auxiliary electrode layer by a vapor phase growth method, and forming a plurality of light emitting layers on the plurality of pixel electrodes by a wet film forming method. The common electrode layer is continuously sputtered over the plurality of light emitting layers, the upper surface of the first feeding auxiliary electrode layer excluding the partial region, and the upper surface of the second feeding auxiliary electrode layer. It includes a step of forming by a method or a CVD (Chemical Vapor Deposition) method.

By this method, it is possible to manufacture an organic EL display panel capable of reducing the electric resistance in the electrical connection between the common electrode layer and the auxiliary electrode layer, improving the luminous efficiency, and suppressing the uneven brightness.
<< Embodiment 1 >>
1.1 Circuit Configuration of Display Device 1 Hereinafter, the circuit configuration of the organic EL display device 1 (hereinafter referred to as “display device 1”) according to the first embodiment will be described with reference to FIG.

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

In the display device 1, the arrangement form of each circuit of the drive control circuit unit 20 with respect to the display panel 10 is not limited to the form shown in FIG.
1.2 Circuit configuration of the display panel 10 In the display panel 10, a plurality of unit pixels 100e are arranged in a matrix to form a display area. Each unit pixel 100e is composed of three organic EL elements, that is, three sub-pixels 100se issued in three colors of R (red), G (green), and B (blue). The circuit configuration of each sub-pixel 100se will be described with reference to FIG.

FIG. 2 is a circuit diagram showing a circuit configuration of the organic EL element 100 corresponding to each sub-pixel 100se of the display panel 10 used in the display device 1.
As shown in FIG. 2, in the display panel 10 according to the present embodiment, each sub-pixel 100se includes two transistors Tr1 and Tr2, one capacitor C, and an organic EL element unit EL as a light emitting unit. Has been done. The transistor Tr1 is a driving transistor, and the transistor Tr2 is a switching transistor.

The gate G2 of the switching transistor Tr2 is connected to the scanning line Vscn, and the source S2 is connected to the data line Vdat. The drain D2 of the switching transistor Tr2 is connected to the gate G1 of the drive transistor Tr1.
The drain D1 of the drive transistor Tr1 is connected to the power supply line Va, and the source S1 is connected to the pixel electrode (anode) of the organic EL element unit EL. The common electrode layer (cathode) in the organic EL element part EL is connected to the ground line Vcat. Further, the first auxiliary electrode layer 135 and the second auxiliary electrode layer 200, which will be described later, are also connected to the ground line Vcat, and the common electrode layer, the first auxiliary electrode layer 135, and the second auxiliary electrode layer 200 are connected to each other. There is.

The first end of the capacitor C is connected to the drain D2 of the switching transistor Tr2 and the gate G1 of the drive transistor Tr1, and the second end of the capacitor C is connected to the power supply line Va.
In the display panel 10, a plurality of adjacent sub-pixels 100se (for example, three sub-pixels 100se of emission colors of red (R), green (G), and blue (B)) are combined to form one unit pixel 100e. However, each unit pixel 100e is arranged so as to be distributed to form a pixel region. Then, a gate line is drawn out from the gate G2 of each sub-pixel 100se, and is connected to a scanning line Vscn connected from the outside of the display panel 10. Similarly, a source line is drawn from the source S2 of each sub-pixel 100se and connected to a data line Vdat connected from the outside of the display panel 10.

Further, the power supply line Va of each sub-pixel 100se and the grounding line Vcat of each sub-pixel 100se are integrated and connected to the power supply line and the grounding line of the display device 1.
1.3 Overall Configuration of Display Panel 10 The display panel 10 according to the present embodiment will be described with reference to the drawings. The drawings are schematic views, and the scale may differ from the actual ones.

FIG. 3 is a schematic plan view showing a part of the display panel according to the embodiment.
The display panel 10 is an organic EL display panel that utilizes the electroluminescence phenomenon of an organic compound, and is a plurality of organic ELs arranged in a matrix on a substrate 100x (TFT substrate) on which a thin film transistor (TFT) is formed. The element 100 has a top emission type configuration that emits light from the upper surface. Here, in the present specification, the X direction, the Y direction, and the Z direction in FIG. 3 are the row direction, the column direction, and the thickness direction in the display panel 10, respectively.

In the display area of the display panel 10, unit pixels 100e composed of a plurality of organic EL elements 100 are arranged in a matrix. Each unit pixel 100e includes 100aR that emits light in red, 100aG that emits light in green, and 100aB that emits light in blue (hereinafter, 100aR, 100aG, 100aB), which is a region that emits light by an organic compound. (Abbreviated as)), three types of self-luminous regions 100a are formed. That is, three sub-pixels 100se corresponding to each of the self-luminous regions 100aR, 100aG, and 100aB arranged in the row direction (hereinafter, when distinguished, "blue sub-pixel 100seB", "green sub-pixel 100seG", and "red sub-pixel" Pixels 100seR ”) form a set to form a unit pixel 100e in color display.

On the display panel 10, a plurality of auxiliary pixel electrodes 150 (FIG. 4) and a plurality of pixel electrodes 119 are arranged in a matrix on the substrate 100x in a row and column direction separated by a predetermined distance from each other. The plurality of auxiliary pixel electrodes 150 and the pixel electrodes 119 have a rectangular shape in a plan view and are made of a light reflecting material. The three auxiliary pixel electrodes 150 and the pixel electrodes 119 arranged in order in the row direction correspond to the three self-luminous regions 100aR, 100aG, and 100aB arranged in order in the row direction.

Further, as shown in FIGS. 3 and 4, a plurality of first auxiliary electrode layers 135 are continuously arranged in the column direction between the unit pixels 100e on the substrate 100x on the display panel 10. The first auxiliary electrode layer 135 is made of a light reflecting material different from that of the pixel electrode 119. Further, on each of the first auxiliary electrode layers 135, the second auxiliary electrode layer 200 is continuously arranged in the row direction between the unit pixels 100e on the substrate 100x. The second auxiliary electrode layer 200 is made of the same light reflecting material as the pixel electrode 119. The width of the first auxiliary electrode layer 135 in the row direction is wider than the width of the second auxiliary electrode layer 200 in the row direction.

Between the adjacent pixel electrodes 119, a bank extending in a line shape in the form of an insulating layer is provided. Further, a bank extending in a line shape in the form of an insulating layer is also provided between the adjacent pixel electrode 119 and the first auxiliary electrode layer 135.
The pixel electrode 119 and the pixel electrode 119 adjacent thereto are insulated from each other. Further, the pixel electrode 119 and the second auxiliary electrode layer 200 or the first auxiliary electrode layer 135 adjacent thereto are insulated from each other.

Between one pixel electrode 119 and the pixel electrode 119 adjacent to the pixel electrode 119 in the row direction (that is, the outer edge 119a3 in the row direction of one pixel electrode 119 and the pixel electrode 119 adjacent to the pixel electrode 119 in the row direction). Between the outer edge 119a4 in the row direction and between one pixel electrode 119 and the first auxiliary electrode layer 135 adjacent to the outer edge 119a4 in the row direction (that is, the outer edge 119a3 in the row direction of one pixel electrode 119). , Between the outer edge 200a2 in the row direction of the first auxiliary electrode layer 135 adjacent to the pixel electrode 119 in the row direction, and the outer edge 119a4 in the row direction of one pixel electrode 119 and the pixel electrode 119 in the row direction. Above the region on the substrate 100x located (between the outer edge 200a1 in the row direction of the adjacent first auxiliary electrode layer 135), there are a plurality of column banks 522Y in which each row extends in the column direction (Y direction in FIG. 3). The rows are arranged side by side. Therefore, the row-direction outer edge of the self-luminous region 100a is defined by the row-direction outer edge of the column bank 522Y.

On the other hand, between one pixel electrode 119 and the pixel electrode 119 adjacent to the pixel electrode 119 in the row direction (that is, the outer edge 119a2 of one pixel electrode 119 in the row direction and the pixel electrode adjacent to the pixel electrode 119 in the row direction). Above the region on the substrate 100x located (between the outer edge 119a1 in the column direction of 119), a plurality of rows of row banks 122X in which each row extends in the row direction (X direction in FIG. 3) are arranged side by side. The region where the row bank 122X is formed is a non-self-luminous region 100b because organic electroluminescence does not occur in the light emitting layer 123 above the pixel electrode 119. Therefore, the outer edge of the self-luminous region 100a in the column direction is defined by the outer edge of the row bank 122X in the column direction.

When the space between adjacent row banks 522Y is defined as the gap 522z, the gap 522z includes a red gap 522zR corresponding to the self-luminous region 100aR, a green gap 522zG corresponding to the self-luminous region 100aG, and a blue gap corresponding to the self-luminous region 100aB. 522 zB, an auxiliary gap 522 zA corresponding to the region where the first auxiliary electrode layer 135 is arranged (hereinafter, referred to as "gap 522 z" when the gap 522 zR, the gap 522 zG, the gap 522 zB, and the gap 522 zA are not distinguished) exists. The display panel 10 adopts a configuration in which a large number of column banks 522Y and gaps 522z are alternately arranged.

In the display panel 10, a plurality of self-luminous regions 100a and non-self-luminous regions 100b are arranged alternately in a row direction along a gap 522zR, a gap 522zG, and a gap 522zB. The non-self-luminous region 100b has a connection recess (contact hole, not shown) that connects the pixel electrode 119 and the source S1 of the TFT, and is formed on the pixel electrode 119 for electrical connection to the pixel electrode 119. A contact area (contact window, not shown) is provided.

In one sub-pixel 100se, the column bank 522Y provided in the column direction and the row bank 122X provided in the row direction are orthogonal to each other, and the self-luminous region 100a is formed in the row bank 122X and the row bank 122X in the column direction. It is located between adjacent row banks 122X.
1.4 Configuration of each part of the display panel 10 The configuration of the organic EL element 100 in the display panel 10 will be described with reference to FIGS. 4 and 5. FIG. 4 is a schematic cross-sectional view taken along the line A1-A1 in FIG. FIG. 5 is an enlarged view of the vicinity of the second auxiliary electrode layer 200 shown in FIG.

In the display panel 10 according to the present embodiment, a substrate (TFT substrate) in which a thin film transistor is formed is formed downward in the Z-axis direction, and an organic EL element portion is formed on the substrate (TFT substrate).
1.4.1 Substrate (1) Substrate 100x
The substrate 100x is a support member for the display panel 10, and has a base material (not shown) and a thin film transistor (TFT) layer (not shown) formed on the base material.

The base material is a support member of the display panel 10 and has a flat plate shape. As the material of the base material, a material having an electrically insulating property, for example, a glass material, a resin material, a semiconductor material, a metal material coated with an insulating layer, or the like can be used.
The TFT layer is composed of a plurality of TFTs formed on the upper surface of the base material and a plurality of wirings including wirings (connecting the source S1 of the TFT and the corresponding pixel electrode 119). The TFT electrically connects the pixel electrode 119 corresponding to itself and the external power supply in response to a drive signal from the external circuit of the display panel 10, and has a multilayer structure such as an electrode, a semiconductor layer, and an insulating layer. .. The wiring electrically connects the TFT, the pixel electrode 119, the external power supply, the external circuit, and the like.

(2) Interlayer insulation layer 118
An interlayer insulating layer 118 is provided on the base material and on the upper surface of the TFT layer. The interlayer insulating layer 118 located on the upper surface of the substrate 100x flattens the upper surface of the substrate 100x having irregularities due to the TFT layer. Further, the interlayer insulating layer 118 fills the space between the wiring and the TFT, and electrically insulates the space between the wiring and the TFT.

In order to connect the pixel electrode 119 and the wiring connected to the source S1 of the corresponding pixel to the interlayer insulating layer 118, a contact hole (shown) is formed in a part of the upper part of the wiring corresponding to the pixel electrode 119. Not) has been opened.
When the upper limit film thickness of the interlayer insulating layer 118 is 10 μm or more, the film thickness variation during manufacturing becomes larger and it becomes difficult to control the bottom line width. From the viewpoint of reducing productivity due to increased tact, the upper limit film thickness of the interlayer insulating layer 118 is preferably 7 μm or less. Further, it is necessary to make the film thickness of the interlayer insulating layer 118 and the bottom line width about the same, and when the film thickness of the interlayer insulating layer 118 becomes thin, the resolution is particularly high when the lower limit film thickness of the interlayer insulating layer 118 is 1 μm or less. It becomes difficult to obtain a desired bottom line width due to the limitation of. In the case of a general flat panel display exposure machine, the lower limit film thickness of the interlayer insulating layer 118 is limited to 2 μm. Therefore, the thickness of the interlayer insulating layer 118 is, for example, preferably 1 μm or more and 10 μm or less, more preferably 2 μm or more and 7 μm or less.

14.2 Organic EL element part (1) Auxiliary pixel electrode 150 and pixel electrode 119
As shown in FIGS. 4 and 5, auxiliary pixel electrodes 150 are provided on the interlayer insulating layer 118 located on the upper surface of the substrate 100x in units of sub-pixels 100se. Further, a pixel electrode 119 is laminated on the auxiliary pixel electrode 150.

The auxiliary pixel electrode 150 and the pixel electrode 119 are for supplying carriers to the light emitting layer 123, and when functioning as an anode, for example, supply holes to the light emitting layer 123. Further, since the display panel 10 is a top emission type, the pixel electrode 119 has light reflectivity. The shapes of the auxiliary pixel electrode 150 and the pixel electrode 119 are rectangular flat plates. The auxiliary pixel electrode 150 and the pixel electrode 119 are arranged in the row direction with an interval δX1 between the auxiliary pixel electrode 150 and the adjacent first auxiliary electrode layer 135. Further, the auxiliary pixel electrode 150 and the pixel electrode 119 are arranged in the row direction with an interval δX2 between the adjacent auxiliary pixel electrode 150 and the pixel electrode 119. A connection recess (contact hole; not shown) of the pixel electrode 119, in which a part of the pixel electrode 119 is recessed in the substrate 100x direction, is formed on the contact hole (not shown) of the interlayer insulating layer 118. At the bottom of the connection recess, the pixel electrode 119 and the wiring connected to the corresponding pixel source S1 are connected.

By forming the auxiliary pixel electrode 150 on the interlayer insulating layer 118, the adhesion is enhanced and hydrogen can be prevented from entering the layer below the interlayer insulating layer 118.
The auxiliary pixel electrode 150 may not be formed on the interlayer insulating layer 118.
(2) First auxiliary electrode layer 135 and second auxiliary electrode layer 200
As shown in FIGS. 4 and 5, a first auxiliary electrode layer 135 is provided on the interlayer insulating layer 118 located on the upper surface of the substrate 100x. As shown in FIG. 5, the first auxiliary electrode layer 135 is arranged with an interval δX1 in the row direction between the first auxiliary electrode layer 135 and the adjacent pixel electrodes 119. Further, as shown in FIG. 5, the first auxiliary electrode layer 135 is arranged with an interval W3 in the row direction between the first auxiliary electrode layer 135 and the base 140 of the adjacent bank 522.

The first auxiliary electrode layer 135 may be in contact with the base 140 of the adjacent bank 522 without a gap W3.
Here, the thickness of the first auxiliary electrode layer 135 is, for example, 50 nm.
Further, as shown in FIGS. 4 and 5, a second auxiliary electrode layer 200 is laminated on the first auxiliary electrode layer 135. The row width W1 of the second auxiliary electrode layer 200 is narrower than the row width W2 of the first auxiliary electrode layer 135. That is, the surface area of the second auxiliary electrode layer 200 is smaller than the surface area of the first auxiliary electrode layer 135.

(3) Hole injection layer 120
As shown in FIG. 4, a hole injection layer 120 is laminated on the pixel electrode 119. The hole injection layer 120 has a function of transporting holes injected from the pixel electrode 119 to the hole transport layer 121.
The hole injection layer 120 includes a lower layer 120A made of a metal oxide formed on the pixel electrode 119 and an upper layer 120B made of an organic substance laminated on at least the lower layer 120A in this order from the substrate 100x side. The lower layer 120A provided in the blue sub-pixel, the green sub-pixel, and the red sub-pixel is referred to as a lower layer 120AB, a lower layer 120AG, and a lower layer 120AR, respectively. Further, the upper layer 120B provided in the blue sub-pixel, the green sub-pixel, and the red sub-pixel is referred to as an upper layer 120BB, an upper layer 120BG, and an upper layer 120BR, respectively.

In the present embodiment, in the gap 522zR, the gap 522zG, and the gap 522zB, which will be described later, the upper layer 120B is linearly provided so as to extend in the row direction. However, the upper layer 120B may be formed only on the lower layer 120A formed on the pixel electrode 119, and may be provided intermittently in the row direction within the gap 522z.
(4) Bank 122
As shown in FIGS. 4 and 5, a bank made of an insulator is formed so as to cover the edges of the pixel electrode 119, the hole injection layer 120, the first auxiliary electrode layer 135, and the second auxiliary electrode layer 200. .. The banks include a column bank 522Y extending in the column direction and arranging a plurality of rows in the row direction, and a row bank 122X extending in the row direction and arranging a plurality of rows in the column direction. As shown in FIG. 3, the column bank 522Y is provided along the row direction orthogonal to the row bank 122X, and the column bank 522Y and the row bank 122X form a grid pattern (hereinafter, row banks). When 122X and column bank 522Y are not distinguished, they are referred to as "bank 122").

The shape of the row bank 122X is a linear shape extending in the row direction, and the cross section cut parallel to the column direction is a forward-tapered trapezoidal shape with an upward taper. The row banks 122X are provided so as to penetrate each column bank 522Y in a state along the row direction orthogonal to the column direction, and each has an upper surface at a position lower than the upper surface 522Yb of the column bank 522Y. Therefore, the row bank 122X and the column bank 522Y form an opening corresponding to the self-luminous region 100a.

The row bank 122X is for controlling the flow of the ink containing the organic compound which is the material of the light emitting layer 123 in the column direction. Therefore, the row bank 122X needs to have a liquidity property with respect to ink of a predetermined value or more. With this configuration, fluctuations in the amount of ink applied between the sub-pixels are suppressed. The pixel electrode 119 is not exposed by the row bank 122X, does not emit light in the region where the row bank 122X exists, and does not contribute to the brightness.

The row bank 122X exists above the outer edges 119a1 and a2 in the column direction of the pixel electrode 119.
The row bank 122X prevents electrical leakage from the common electrode layer 125 and defines the outer edge of the light emitting region 100a of each sub-pixel 100se in the column direction.
The shape of the column bank 522Y is a linear shape extending in the column direction, and the cross section cut parallel to the row direction is a forward-tapered trapezoidal shape with an upward taper. The column bank 522Y defines the outer edge in the row direction of the light emitting layer 123 formed by blocking the flow of the ink containing the organic compound which is the material of the light emitting layer 123 in the row direction.

The base of the column bank 522Y is defined by the outer edges 119a3 and a4 above the pixel electrodes 119 in the row direction and the outer edges 200a1 and a2 in the row direction of the first auxiliary electrode layer 135. The column bank 522Y prevents electrical leakage from the common electrode layer 125 and defines the outer edge of the light emitting region 100a of each sub-pixel 100se in the row direction. The row bank 522Y needs to have a liquid repellency against ink of a predetermined value or more.

(5) Hall transport layer 121
As shown in FIG. 4, the hole transport layer 121 is laminated on the hole injection layer 120 in the gap 522zR, 522zG, 522zB. Further, the hole transport layer 121 is also laminated on the hole injection layer 120 in the row bank 122X (not shown). The hole transport layer 121 is in contact with the upper layer 120B of the hole injection layer 120. The hole transport layer 121 has a function of transporting holes injected from the hole injection layer 120 to the light emitting layer 123. The hole transport layer 121 provided in the gap 522 zR, 522 zG, and 522 zB is referred to as a hole transport layer 121R, a hole transport layer 121G, and a hole transport layer 121B, respectively.

In the present embodiment, in the gap 522z described later, the hole transport layer 121 is linearly provided so as to extend in the row direction, similarly to the upper layer 120B. However, the hole transport layer 121 may be provided intermittently in the row direction within the gap 522z.
(6) Light emitting layer 123
As shown in FIG. 4, a light emitting layer 123 is laminated on the hole transport layer 121. The light emitting layer 123 is a layer made of an organic compound, and has a function of emitting light by recombining holes and electrons inside. Within the gap 522zR, the gap 522zG, and the gap 522zB defined by the row bank 522Y, the light emitting layer 123 is linearly provided so as to extend in the row direction. The red gap 522zR corresponding to the self-luminous region 100aR in the red sub-pixel 100seR, the green gap 522zG corresponding to the self-luminous region 100aG in the green sub-pixel 100seG, and the blue gap 522zB corresponding to the self-luminous region 100aB in the blue sub-pixel 100seB. Is formed with light emitting layers 123R, 123G, and 123B that emit light in each color, respectively.

Since the light emitting layer 123 emits light only at the portion where the carrier is supplied from the pixel electrode 119, the electroluminescence phenomenon of the organic compound does not occur in the range where the row bank 122X which is an insulator exists between the layers. Therefore, in the light emitting layer 123, only the portion without the row bank 122X emits light, and this portion becomes the self-luminous region 100a, and the outer edge of the self-luminous region 100a in the column direction is defined by the column direction outer edge of the row bank 122X. ..

Of the light emitting layer 123, the portion above the side surface and the upper surface of the row bank 122X does not emit light, and this portion becomes a non-self-luminous region. The light emitting layer 123 is located on the upper surface of the hole transport layer 121 in the self-luminous region, and is located on the upper surface of the row bank 122X and the upper surface of the hole transport layer 121 on the side surface in the non-self-luminous region 100b (not shown).
The light emitting layer 123 is continuously extended not only to the self-luminous region 100a but also to the adjacent non-self-luminous region. In this way, when the light emitting layer 123 is formed, the ink applied to the self-luminous region 100a can flow in the row direction through the ink applied to the non-self-luminous region, and the film thickness is leveled between the pixels in the row direction. Can be transformed into. However, in the non-self-luminous region, the row bank 122X moderately suppresses the flow of ink. Therefore, large film thickness unevenness is less likely to occur in the column direction, and brightness unevenness for each pixel is improved.

(7) Electron transport layer 124
As shown in FIGS. 3, 4 and 5, the electron transport layer 124 is laminated so as to cover the gap 522z defined by the row bank 522Y and the row bank 522Y. The electron transport layer 124 is formed in a continuous state over the entire display panel 10.
The electron transport layer 124 is formed on the light emitting layer 123 as shown in FIGS. 4 and 5. The electron transport layer 124 has a function of transporting electrons from the common electrode layer 125 to the light emitting layer 123 and limiting the injection of electrons into the light emitting layer 123.

As shown in FIGS. 4 and 5, the electron transport layer 124 includes a first auxiliary electrode layer 135 (excluding a portion on the first auxiliary electrode layer 135 on which the second auxiliary electrode layer 200 is formed) and a second auxiliary electrode layer. It is also formed on the electrode layer 200. The electron transport layer 124 is missing (stepped) at the end of the first auxiliary electrode layer 135 and the end of the second auxiliary electrode layer 200. In the missing portions 136 and 139, the first auxiliary electrode layer 135 and the common electrode layer 125 are in direct contact with each other. Further, in the missing portions 137 and 138, the first auxiliary electrode layer 135 and the common electrode layer 125 are in direct contact with each other, and the second auxiliary electrode layer 200 and the common electrode layer 125 are in direct contact with each other.

(8) Common electrode layer 125
As shown in FIGS. 4 and 5, a common electrode layer 125 is formed on the electron transport layer 124. The common electrode layer 125 is formed over the entire surface of the display panel 10 and serves as a common electrode for each light emitting layer 123.
As shown in FIG. 4, the common electrode layer 125 is also formed in the region above the pixel electrode 119 on the electron transport layer 124. The common electrode layer 125 is paired with the pixel electrode 119 to form an energization path by sandwiching the light emitting layer 123, and supplies carriers to the light emitting layer 123. For example, when it functions as a cathode, it goes to the light emitting layer 123. Supply electrons.

As shown in FIGS. 4 and 5, the common electrode layer 125 includes a first auxiliary electrode layer 135 (excluding a portion on the first auxiliary electrode layer 135 on which the second auxiliary electrode layer 200 is formed) and a second auxiliary electrode layer 125. It is also formed in the region above the electrode layer 200. The common electrode layer 125 is formed in the missing portions 136, 137, 138, and 139 of the electron transport layer 124 so as to be in direct contact with the first auxiliary electrode layer 135 and the second auxiliary electrode layer 200.

(9) Sealing layer 126
The sealing layer 126 is laminated so as to cover the common electrode layer 125. The sealing layer 126 is for suppressing the light emitting layer 123 from deteriorating due to contact with moisture, air, or the like. The sealing layer 126 is provided over the entire surface of the display panel 10 so as to cover the upper surface of the common electrode layer 125.

(10) Bonding layer 127
Above the sealing layer 126 in the Z-axis direction, a color filter substrate 131 having a color filter layer 128 formed on the main surface on the lower side in the Z-axis direction of the upper substrate 130 is arranged and bonded by the bonding layer 127. There is. The bonding layer 127 has a function of bonding the back panel composed of each layer from the substrate 100x to the sealing layer 126 and the color filter substrate 131, and preventing each layer from being exposed to moisture or air.

(11) Upper substrate 130
A color filter substrate 131 having a color filter layer 128 formed on the upper substrate 130 is installed and bonded on the bonding layer 127. Since the display panel 10 is a top emission type for the upper substrate 130, a light transmitting material such as a cover glass or a transparent resin film is used for the upper substrate 130. Further, the upper substrate 130 can improve the rigidity of the display panel 10 and prevent the intrusion of moisture, air, and the like.

(12) Color filter layer 128
A color filter layer 128 is formed on the upper substrate 130 at a position corresponding to each color self-luminous region 100a of the pixel. The color filter layer 128 is a transparent layer provided for transmitting visible light having wavelengths corresponding to R, G, and B, and has a function of transmitting light emitted from each color pixel and correcting its chromaticity. Have. For example, in this example, the red, green, and blue filter layers 128R and 128G are above the self-luminous region 100aR in the red gap 522zR, the self-luminous region 100aG in the green gap 522zG, and the self-luminous region 100aB in the blue gap 522zB. , 128B are formed respectively.

(13) Light-shielding layer 129
A light-shielding layer 129 is formed on the upper substrate 130 at a position corresponding to the boundary between the light emitting regions 100a of each pixel. The light-shielding layer 129 is a black resin layer provided to prevent visible light having wavelengths corresponding to R, G, and B from being transmitted, and is made of, for example, a resin material containing a black pigment having excellent light absorption and light-shielding properties.

1.4.3 Constituent materials of each part An example of the constituent materials of each part shown in FIGS. 3, 4 and 5 is shown.
(1) Substrate 100x (TFT substrate)
Examples of the base material include glass substrates, quartz substrates, silicon substrates, molybdenum sulfide, copper, zinc, aluminum, stainless steel, magnesium, iron, nickel, gold, silver and other metal substrates, gallium arsenic groups and other semiconductor substrates, and plastics. A substrate or the like can be adopted. Further, as the flexible plastic material, either a thermoplastic resin or a thermosetting resin may be used. As the material, a material having electrical insulation, for example, a resin material can be used. Known materials can be used for the gate electrode, the gate insulating layer, the channel layer, the channel protection layer, the source electrode, the drain electrode, and the like constituting the TFT. As the gate electrode, for example, a laminated body of copper (Cu) and molybdenum (Mo) is adopted. As the gate insulating layer, any known organic material or inorganic material can be used as long as it is a material having electrical insulating properties such as silicon _{oxide (SiO 2) and silicon nitride (SiNx).} As the channel layer, an oxide semiconductor containing at least one selected from indium (In), gallium (Ga), and zinc (Zn) can be adopted. As the channel protection layer, for example, silicon oxynitride (SiON), silicon nitride (SiNx), or aluminum oxide (AlOx) can be used. As the source electrode and drain electrode, for example, a laminate of copper manganese (CuMn), copper (Cu), and molybdenum (Mo) can be adopted.

For the insulating layer on the upper part of the TFT, for example, silicon oxide (SiO ₂ ), silicon nitride (SiN), silicon oxynitride (SiON), silicon oxide (SiO) or silicon oxynitride (SiON) can be used. As the connection electrode layer of the TFT, for example, a laminate of molybdenum (Mo), copper (Cu), and copper manganese (CuMn) can be adopted. The material used for the construction of the connection electrode layer is not limited to this, and can be appropriately selected from conductive materials.

As the material of the interlayer insulating layer 118 located on the upper surface of the substrate 100x, for example, an organic compound such as a polyimide resin, an acrylic resin, a siloxane resin, or a novolak type phenol resin can be used.
(2) Pixel electrode 119, auxiliary pixel electrode 150, second auxiliary electrode layer 200 and first auxiliary electrode layer 135
The pixel electrode 119 is made of a metal material. In the case of the display panel 10 according to the present embodiment of the top emission type, the chromaticity of the emitted light is adjusted and the brightness is increased by optimally setting the thickness and adopting the optical resonator structure. , It is necessary that the surface portion of the pixel electrode 119 has high reflectivity. In the display panel 10 according to the present embodiment, the pixel electrode 119 may have a structure in which a plurality of films selected from a metal layer, an alloy layer, and a transparent conductive film are laminated. The metal layer can be made of, for example, a metal material containing silver (Ag) or aluminum (Al). As the alloy layer, for example, APC (alloy of silver, palladium, copper), ARA (alloy of silver, rubidium, gold), MoCr (alloy of molybdenum and chromium), NiCr (alloy of nickel and chromium) and the like are used. Can be done. As the constituent material of the transparent conductive layer, for example, indium tin oxide (ITO), indium zinc oxide (IZO), or the like can be used.

The second auxiliary electrode layer 200 is made of the same material as the pixel electrode 119.
The first auxiliary electrode layer 135 is formed of, for example, a metal material such as tungsten (W), molybdenum (Mo), nickel (Ni), copper (Cu), lanthanum (La), and indium (In).
The auxiliary pixel electrode 150 is made of the same material as the first auxiliary electrode layer 135.

(3) Hole injection layer 120
The lower layer 120A of the hole injection layer 120 is composed of oxides such as silver (Ag), molybdenum (Mo), chromium (Cr), vanadium (V), tungsten (W), nickel (Ni), and iridium (Ir). It is a layer consisting of. When the lower layer 120A is composed of an oxide of a transition metal, a plurality of oxidation numbers are taken, so that a plurality of levels can be taken, and as a result, hole injection is facilitated and the driving voltage is reduced. Can be done. In the present embodiment, the lower layer 120A is configured to contain an oxide of tungsten (W). At this time, as for the oxide of tungsten (W), the ^{larger the ratio of the hexavalent tungsten atom of the pentavalent tungsten atom (W 5+} / W ⁶⁺ ), the lower the driving voltage of the organic EL element, so that the pentavalent tungsten It is preferable that the amount of atoms is more than a predetermined value.

As described above, as the upper layer 120B of the hole injection layer 120, a coating film made of an organic polymer solution of a conductive polymer material such as PEDOT (mixture of polythiophene and polystyrene sulfonic acid) can be used.
(4) Bank 122
The bank 122 is formed by using an organic material such as a resin and has an insulating property. Examples of the organic material used for forming the bank 122 include an acrylic resin, a polyimide resin, a novolak type phenol resin, and the like. The bank 122 preferably has organic solvent resistance. More preferably, it is desirable to use an acrylic resin. This is because it has a low refractive index and is suitable as a reflector.

Alternatively, when an inorganic material is used for the bank 122, for example, silicon oxide (SiO) is preferably used from the viewpoint of the refractive index. Alternatively, for example, it is formed by using an inorganic material such as silicon nitride (SiN) or silicon oxynitride (SiON).
Further, since the bank 122 may be subjected to an etching treatment, a baking treatment, or the like during the manufacturing process, the bank 122 is formed of a material having high resistance to such treatments so as not to be excessively deformed or deteriorated. Is preferable.

In addition, the surface can be treated with fluorine in order to make the surface water repellent. Further, a material containing fluorine may be used for forming the bank 122. Further, in order to reduce the water repellency on the surface of the bank 122, the bank 122 may be subjected to a baking treatment at a low temperature by irradiating the bank 122 with ultraviolet rays.
(5) Hall transport layer 121
The hole transport layer 121 is, for example, polyfluorene or a derivative thereof, a polymer compound such as polyarylamine which is an amine-based organic polymer or a derivative thereof, or TFB (poly (9, 9-di-n-octylfluorene-). Alt- (1,4-phenylene-((4-sec-butylphenyl) imino) -1,4-phenylene)) and the like can be used.

(6) Light emitting layer 123
As described above, the light emitting layer 123 has a function of generating an excited state and emitting light by injecting holes and electrons and recombining them. As the material used for forming the light emitting layer 123, it is necessary to use a luminescent organic material that can form a film by using a wet printing method.
Specifically, for example, an oxinoid compound, a perylene compound, a coumarin compound, an azacmarin compound, an oxazole compound, an oxaziazole compound, a perinone compound, and pyrolopyrrole described in Japanese Patent Application Laid-Open No. 5-163488. Compounds, naphthalene compounds, anthracene compounds, fluorene compounds, fluoranthene compounds, tetracene compounds, pyrene compounds, coronen compounds, quinolone compounds and azaquinolone compounds, pyrazoline derivatives and pyrazolone derivatives, rhodamine compounds, chrysene compounds, phenanthrene compounds, cyclopentadiene compounds, stillben compounds , Diphenylquinone compound, styryl compound, butadiene compound, dicyanomethylenepyran compound, dicyanomethylenethiopyran compound, fluorescein compound, pyririum compound, thiapyrrium compound, selenapyrium compound, tellropyrylium compound, aromatic aldaziene compound, oligophenylene compound, thioxanthene Formed from fluorescent substances such as compounds, anthracene compounds, cyanine compounds, acrydin compounds, metal complexes of 8-hydroxyquinoline compounds, metal complexes of 2-bipyridine compounds, complexes of shift salts and Group III metals, oxine metal complexes, and rare earth complexes. It is preferable that the compound is used.

(7) Electron transport layer 124
For the electron transport layer 124, an organic material having high electron transportability is used. Examples of the organic material used for the electron transport layer 124 include π-electron low molecular weight organic materials such as an oxadiazole derivative (OXD), a triazole derivative (TAZ), and a phenanthroline derivative (BCP, Bphen). Further, the electron transport layer 124 may include a layer formed by doping an organic material having high electron transport property with a dope metal selected from an alkali metal or an alkaline earth metal. Further, the electron transport layer 124 may include a layer formed of sodium fluoride. Specifically, the alkali metal is Li (lithium), Na (sodium), K (potassium), Rb (rubidium), Cs (cesium), Fr (francium). Specific examples of the alkaline earth metal are Ca (calcium), Sr (strontium), Ba (barium), and Ra (radium).

(8) Common electrode layer 125
For the common electrode layer 125, a conductive material having light transmittance is used. For example, it is formed using indium tin oxide (ITO), zinc indium oxide (IZO), or the like. Further, an electrode obtained by thinning silver (Ag), aluminum (Al) or the like may be used.
(9) Sealing layer 126
The sealing layer 126 has a function of suppressing the organic layer such as the light emitting layer 123 from being exposed to moisture or air, and is, for example, silicon nitride (SiN), silicon oxynitride (SiON), or the like. It is formed using the translucent material of. Further, a sealing resin layer made of a resin material such as an acrylic resin or a silicon resin may be provided on a layer formed by using a material such as silicon nitride (SiN) or silicon oxynitride (SiON).

In the case of the display panel 10 according to the present embodiment, which is a top emission type, the sealing layer 126 needs to be formed of a light-transmitting material.
(10) Bonding layer 127
The material of the bonding layer 127 is, for example, a resin adhesive or the like. For the bonding layer 127, a translucent resin material such as an acrylic resin, a silicon resin, or an epoxy resin can be adopted.

(11) Upper substrate 130
As the upper substrate 130, for example, a translucent material can be adopted for a glass substrate, a quartz substrate, a plastic substrate, or the like.
(12) Color filter layer 128
As the color filter layer 128, a known resin material (for example, as a commercially available product, a color resist manufactured by JSR Corporation) or the like can be adopted.

(13) Light-shielding layer 129
The light-shielding layer 129 is made of a resin material containing an ultraviolet curable resin (for example, an ultraviolet curable acrylic resin) as a main component and a black pigment added thereto. As the black pigment, for example, a light-shielding material such as a carbon black pigment, a titanium black pigment, a metal oxide pigment, or an organic pigment can be adopted.

1.5 Manufacturing Method of Display Panel 10 The manufacturing method of the display panel 10 will be described with reference to FIGS. 6 to 11.
(1) Preparation of substrate 100x Prepare a substrate 100x on which a plurality of TFTs and wirings are formed. The substrate 100x can be manufactured by a known TFT manufacturing method (FIG. 6A).

(2) Formation of Interlayer Insulation Layer 118 An interlayer insulation layer is applied by applying the above-mentioned constituent material (photosensitive resin material) of the interlayer insulation layer 118 as a photoresist so as to cover the substrate 100x, and flattening the surface. It forms 118 (FIG. 6 (b)).
After forming the interlayer insulating layer 118, a photomask having a predetermined opening is overlapped, and ultraviolet rays are irradiated from above to expose the interlayer insulating layer 118, and the pattern of the photomask is transferred (FIG. 6 (c). )).

Then, the interlayer insulating layer 118 in which the contact holes 118a are patterned is formed by development (FIG. 6 (d)). At the bottom of the contact hole 118a, the wiring on the substrate 100x is exposed.
In the present embodiment, the interlayer insulating layer 118 is formed by using a positive type photoresist, but the interlayer insulating layer 118 may be formed by using a negative type photoresist.

(3) Formation of Auxiliary Pixel Electrode 150 and First Auxiliary Electrode Layer 135 After the interlayer insulating layer 118 having the contact hole 118a is formed, the auxiliary pixel electrode 150 and the first auxiliary electrode layer 135 are formed (FIG. 7 (FIG. 7). a)).
The auxiliary pixel electrode 150 and the first auxiliary electrode layer 135 are formed by forming a metal film by a sputtering method or the like and then patterning by a photolithography method and an etching method. At this time, the connection recess of the auxiliary pixel electrode 150 is formed by forming a metal film along the inner wall of the contact hole 118a.

The auxiliary pixel electrode 150 comes into direct contact with the wiring on the exposed substrate 100x at the bottom of the contact hole 118a, and is in a state of being electrically connected to the electrode of the TFT.
(4) Formation of Pixel Electrode 119 and Second Auxiliary Electrode Layer 200 After the auxiliary pixel electrode 150 and the first auxiliary electrode layer 135 are formed, the pixel electrodes are placed on the auxiliary pixel electrode 150 and the first auxiliary electrode layer 135, respectively. 119 and the second auxiliary electrode layer 200 are formed (FIG. 7 (a)).

The pixel electrode 119 and the second auxiliary electrode layer 200 are formed by forming a metal film by a sputtering method or the like and then patterning by a photolithography method and an etching method.
(5) Formation of Lower Layer 120A of Hole Injection Layer 120 After forming the pixel electrode 119 and the second auxiliary electrode layer 200, the lower layer 120A of the hole injection layer 120 is formed on the pixel electrode 119 (FIG. 7). (B)).

The lower layer 120A is oxidized by firing after forming a film made of a metal (for example, tungsten) by a vapor phase growth method such as a sputtering method or a vacuum vapor deposition method, and is used for each pixel unit by a photolithography method and an etching method. It is formed by patterning.
(6) Formation of Bank 122 After forming the lower layer 120A of the hole injection layer 120, the bank 122 is formed so as to cover the lower layer 120A (FIG. 7 (c)).

In the formation of the bank 122, the row bank 122X is first formed, and then the column bank 522Y is formed so as to form the gap 522Z.
To form the bank 122, first, a film made of a constituent material of the bank 122 (for example, a photosensitive resin material) is laminated on the lower layer 120A by using a spin coating method or the like. Then, the resin film is patterned to form the row bank 122X and the column bank 522Y in this order. The patterning of the row bank 122X and the column bank 522Y is performed by exposing the resin film on the resin film using a photomask and performing a developing step and a firing step (about 230 ° C., about 60 minutes).

Specifically, in the step of forming the row bank 122X, first, a photosensitive resin film made of an organic photosensitive resin material, for example, an acrylic resin, a polyimide resin, a novolak type phenol resin, or the like is formed, and then dried. Then, after volatilizing the solvent to some extent, a photomask having a predetermined opening is overlapped, and ultraviolet irradiation is performed on the photoresist to expose a photoresist made of a photosensitive resin or the like, and the photoresist has a photoresist. Transfer the pattern. Next, the photosensitive resin is developed to form an insulating layer in which the row bank 122X is patterned. Generally, a photoresist called a positive type is used. In the positive type, the exposed part is removed by development. The portion of the mask pattern that is not exposed remains undeveloped.

In the step of forming the row bank 522Y, first, a film made of a constituent material (for example, a photosensitive resin material) of the row bank 522Y is laminated and formed by using a spin coating method or the like. Then, the resin film is patterned to open a gap 522z to form a row bank 522Y. The gap 522z is formed by arranging a mask above the resin film, exposing it, and then developing it. The column banks 522Y are extended in the column direction and juxtaposed with the gap 522z in the row direction.

(7) Formation of Organic Functional Layer The upper layer 120B of the hole injection layer 120 with respect to the lower layer 120A of the hole injection layer 120 formed in the gap 522z defined by the column bank 522Y including the row bank 122X. The hole transport layer 121 and the light emitting layer 123 are laminated and formed in this order (FIGS. 7 (d) and 8 (a)).

The upper layer 120B uses an inkjet method to apply an ink containing a conductive polymer material such as PEDOT (a mixture of polythiophene and polystyrene sulfonic acid) into the gap 522z defined by the row bank 522Y, and then volatilize and remove the solvent. Let me. Alternatively, it is done by firing. After that, patterning may be performed for each pixel by using a photolithography method and an etching method.

The hole transport layer 121 uses a wet process by an inkjet method or a gravure printing method to apply ink containing a constituent material within the gap 522z defined by the row bank 522Y, and then volatilize and remove the solvent. Alternatively, it is done by firing. The method of applying the ink of the hole transport layer 121 in the gap 522z is the same as the method of the upper layer 120B described above. Alternatively, a film made of a metal (for example, tungsten) is deposited by a sputtering method and oxidized by firing to form a film. After that, patterning may be performed for each pixel by using a photolithography method and an etching method.

The light emitting layer 123 is formed by applying an ink containing a constituent material in the gap 522z defined by the row bank 522Y using an inkjet method and then firing the ink. Specifically, in this step, the gap 522z, which is the sub-pixel forming region, is filled with inks 123RI, 123GI, and 123BI containing the material of any of R, G, and B organic light emitting layers by the inkjet method, respectively. Light emitting layers 123R, 123G, and 123B are formed by drying the ink under reduced pressure and baking it. At this time, in applying the ink to the light emitting layer 123, first, a solution for forming the light emitting layer 123 is applied using a droplet ejection device. After the application of the ink for forming any of the red light emitting layer, the green light emitting layer, and the blue light emitting layer to the substrate 100x is completed, the ink of another color is applied to the substrate, and then the substrate is coated. The process of applying the third color ink to the ink is repeated, and the three color inks are applied in sequence. As a result, the red light emitting layer, the green light emitting layer, and the blue light emitting layer are repeatedly formed on the substrate 100x in the lateral direction of the paper surface in the drawing. The details of the method of applying the ink of the light emitting layer 123 in the gap 522z are the same as the method of the upper layer 120B described above.

The method for forming the upper layer 120B, the hole transport layer 121, and the light emitting layer 123 of the hole injection layer 120 is not limited to the above method, and methods other than the inkjet method and the gravure printing method, such as the dispenser method, the nozzle coating method, and the spin coating method. Ink may be dropped or applied by a known method such as a method, intaglio printing, or letterpress printing.
(8) Formation of Electron Transport Layer 124 After the light emitting layer 123 is formed, the electron transport layer 124 is formed over the entire surface of the display panel 10 by a vacuum vapor deposition method or the like (FIG. 8 (b)). The electron transport layer 124 is also formed on the second auxiliary electrode layer 200 and the first auxiliary electrode layer 135 (excluding the portion on the first auxiliary electrode layer 135 on which the second auxiliary electrode layer 200 is formed). .. At that time, a gap (step break) was intentionally generated at the end of the second auxiliary electrode layer 200 and the end of the first auxiliary electrode layer 135, and the missing portion 136, 137, 138, 139 (FIG. 5). The film is formed so that the end portion of the second auxiliary electrode layer 200 and the end portion of the first auxiliary electrode layer 135 are exposed.

(9) Formation of Common Electrode Layer 125 After forming the electron transport layer 124, the common electrode layer 125 is formed by a CVD (Chemical Vapor Deposition) method, a sputtering method, or the like so as to cover the electron transport layer 124 (FIG. 8 (c)). The common electrode layer 125 is a second auxiliary electrode layer 200 and a first auxiliary electrode layer 135 on the electron transport layer 124 (excluding a portion on the first auxiliary electrode layer 135 on which the second auxiliary electrode layer 200 is formed). It is also formed in the upper region. At that time, the common electrode layer 125 wraps around the missing portion 136, 137, 138, 139 (FIG. 5) of the electron transport layer 124, and the end of the second auxiliary electrode layer 200 exposed in the missing portion of the electron transport layer 124. The film is formed so as to be in direct contact with the portion and the end portion of the first auxiliary electrode layer 135.

Here, a method for forming the common electrode layer 125 will be further described.
First, the schematic configuration of the sputtering apparatus 600 will be described with reference to FIG. The sputtering apparatus 600 has a substrate transfer chamber 610, a film forming chamber 620, and a load lock chamber 630, and sputtering is performed in the film forming chamber 620 by a magnetron sputtering method. Sputtering gas is introduced into the film forming chamber 620. As the sputtering gas, an inert gas such as Ar (argon) is used. In this embodiment, Ar is used.

A substrate 622 to be formed is installed on the carrier 621 in the sputtering apparatus 600. The substrate 622 is mounted on the carrier 621 by the substrate pushing mechanism 611 in the substrate delivery chamber 610. The carrier 621 on which the substrate 622 is mounted moves linearly on the transport path 601 from the substrate delivery chamber 610 to the load lock chamber 630 via the film formation chamber 620 at a constant speed. In this embodiment, the moving speed of the carrier 621 is 30 mm / s. The substrate 622 is not heated, and sputtering is performed at room temperature.

In the film forming chamber 620, a rod-shaped target 623 extending in a direction orthogonal to the transport path 601 is installed. In this embodiment, the target 623 is ITO. The target 623 does not have to be rod-shaped, and may be, for example, powder-shaped.
The power supply 624 applies a voltage to the target 623. Although the power supply 624 is an AC power supply in FIG. 11, it may be a DC power supply or a DC / AC hybrid power supply.

The inside of the sputtering apparatus 600 is exhausted by the exhaust system 631, and the sputtering gas is introduced into the film forming chamber 620 by the gas supply system 632. When a voltage is applied to the target 623 by the power supply 624, plasma of sputtering gas is generated, and the surface of the target 623 is sputtered. Then, the sputtered atoms of the target 623 are deposited on the substrate 622 to form a film.

The gas pressure of Ar, which is a sputtering gas, is, for example, 0.6 Pa, and the flow rate is 100 sccm.
(10) Formation of Sealing Layer 126 After forming the common electrode layer 125, the sealing layer 126 is formed so as to cover the common electrode layer 125 (FIG. 8 (d)). The sealing layer 126 can be formed by using a CVD method, a sputtering method, or the like.

(11) Formation of Color Filter Substrate 131 Next, a manufacturing process of the color filter substrate 131 will be illustrated.
A transparent upper substrate 130 is prepared, and a material of a light-shielding layer 129 made of an ultraviolet curable resin (for example, an ultraviolet curable acrylic resin) as a main component and a black pigment added thereto is applied to one surface of the transparent upper substrate 130. Apply (Fig. 9 (a)).

A pattern mask PM having a predetermined opening is placed on the upper surface of the coated light-shielding layer 129, and ultraviolet rays are irradiated from above (FIG. 9 (b)).
Then, the pattern mask PM and the uncured light-shielding layer 129 are removed, developed, and cured to complete the light-shielding layer 129 having a rectangular cross-sectional shape (FIG. 9 (c)).
Next, a material 128G of a color filter layer 128 (for example, G) containing an ultraviolet curable resin component as a main component is applied to the surface of the upper substrate 130 on which the light-shielding layer 129 is formed (FIG. 9D) to obtain a predetermined pattern. A mask PM is placed and irradiated with ultraviolet rays (FIG. 9 (e)).

After that, curing is performed to remove the pattern mask PM and the uncured paste 128R and developed to form a color filter layer 128 (G) (FIG. 9 (f)).
By repeating the steps of FIGS. 9 (d), 9 (e), and (f) in the same manner for the color filter materials of each color, the color filter layers 128 (R) and 128 (B) are formed (FIG. 9 (g)). ). Instead of using the paste 128R, a commercially available color filter product may be used.

With the above, the color filter substrate 131 is formed.
(12) Bonding of Color Filter Substrate 131 and Back Panel Next, the back panel composed of each layer from the substrate 100x to the sealing layer 126 is mainly composed of an ultraviolet curable resin such as an acrylic resin, a silicon resin, or an epoxy resin. The material of the bonding layer 127 to be used is applied (FIG. 10 (a)).

Subsequently, the applied material is irradiated with ultraviolet rays, and both substrates are bonded together with the relative positional relationship between the back panel and the color filter substrate 131 matched. At this time, be careful not to let gas enter between the two. After that, when both substrates are fired to complete the sealing step, the display panel 10 is completed (FIG. 10 (b)).
1.6 Summary When a metal such as aluminum, copper, or silver is used as the material of the auxiliary electrode layer, an oxide film is formed on the surface (surface layer) of the auxiliary electrode layer, and the auxiliary electrode layer and the common electrode layer are formed. Contact resistance increases.

In order to solve this problem, the display panel 10 is formed by arranging a plurality of pixel electrodes 119 in a matrix on a substrate 100x and arranging a light emitting layer 123 containing an organic light emitting material on each pixel electrode 119. .. The display panel 10 is arranged in a gap of at least one of the gaps between the substrate 100x, the plurality of pixel electrodes 119 arranged in a matrix above the substrate 100x, and the adjacent pixel electrodes 119 above the substrate 100x. Alternatively, the first auxiliary electrode layer 135 stretched in the row direction and the second auxiliary electrode stretched in the same direction as the first auxiliary electrode layer 135 in a part of the region on the first auxiliary electrode layer 135. The layer 200, the plurality of light emitting layers 123 arranged on the plurality of pixel electrodes 119, the upper surface of the plurality of light emitting layers 123 excluding a part of the first auxiliary electrode layer 135, and the second auxiliary electrode layer 200. It is provided with a common electrode layer 125 which is continuously arranged so as to cover the upper upper surface. Here, the first auxiliary electrode layer 135 contains a first metal as a main component, and the second auxiliary electrode layer 200 contains a second metal different from the first metal as a main component. The surface resistance of the second auxiliary electrode layer 200 is higher than the surface resistance of the first auxiliary electrode layer 135.

According to this configuration, the common electrode layer 125 is in contact with the first auxiliary electrode layer 135 (excluding some of the above regions), and the first auxiliary electrode layer 135 is in contact with the second auxiliary electrode layer 200. That is, the common electrode layer 125 comes into contact with the second auxiliary electrode layer 200 via the first auxiliary electrode layer 135. Therefore, even when an oxide film is formed on the surface layer of the second auxiliary electrode layer 200, the electrical between the common electrode layer and the second auxiliary electrode layer is obtained through the first auxiliary electrode layer 135. It is possible to reduce the electrical resistance in the connection. As a result, it is possible to improve the luminous efficiency and suppress the uneven brightness.

Here, when tungsten or molybdenum is used as the material of the first auxiliary electrode layer 135, since these metals are chemically stable at room temperature, an oxide film is formed on the surface of the first auxiliary electrode layer 135. Not done.
The contact resistance between the second auxiliary electrode layer 200 and the common electrode layer 125 is higher than the first predetermined value, and the resistance between the first auxiliary electrode layer 135 and the common electrode layer 125 is the first predetermined value. Lower.

Further, the sheet resistance of the second auxiliary electrode layer 200 is lower than the second predetermined value, the sheet resistance of the first auxiliary electrode layer 135 is higher than the sheet resistance of the second auxiliary electrode layer 200, and the sheet of the common electrode layer 125. The resistance is higher than the second predetermined value.
By bringing the common electrode layer 125 and the first auxiliary electrode layer 135 (excluding the portion on which the second auxiliary electrode layer 200 is formed) into contact with each other, the common electrode layer 125 and the second auxiliary electrode layer 200 can be brought into contact with each other. It is possible to reduce the resistance more than the contact resistance of.

Further, since the sheet resistance of the second auxiliary electrode layer 200 is smaller than the sheet resistance of the first auxiliary electrode layer 135, the first metal (for example, for example, the first auxiliary electrode layer 135 and the second auxiliary electrode layer 200 as a whole Compared with the case of using tungsten), the overall sheet resistance of the first auxiliary electrode layer 135 and the second auxiliary electrode layer 200 can be reduced.
Further, as shown in FIG. 5, in the electron transport layer 124, a chip (step break) occurs at the end of the second auxiliary electrode layer 200 and the end of the first auxiliary electrode layer 135, and the missing portion 136, In 137, 138, and 139, the common electrode layer 125 and the first auxiliary electrode layer 135 are in direct contact with each other, and the common electrode layer 125 and the second auxiliary electrode layer 200 are in direct contact with each other, so that resistance can be reduced. Become.

1.7 Modifications Although the display panel 10 according to the first embodiment has been described, the present disclosure is not limited to the above embodiments except for its essential characteristic components. For example, a form obtained by applying various modifications to the embodiment that a person skilled in the art can think of, or a form realized by arbitrarily combining the components and functions in each embodiment without departing from the spirit of the present invention. Is also included in this disclosure. Hereinafter, as an example of such a form, a modified example of the display panel 10 will be described.

(1) In the missing portions 136, 137, 138, and 139 shown in FIG. 5, the missing (step break) may not occur and the thin film of the electron transport layer 124 may be formed.
In the electron transport layer 124, although at least a part of the missing portions 136, 137, 138, and 139 shown in FIG. 5 is not missing, a thinned portion (thinned portion) is thinned to a film thickness of 1 nm or less. (Not shown) may be formed. Although a part of the electron transport layer 124 is not missing due to such a configuration, the common electrode layer 125 has a lower electric resistance in the thinned portion of the electron transport layer 124 than in the portion other than the thinned portion. A structure that is electrically connected to the second auxiliary electrode layer 200 or the first auxiliary electrode layer 135 can be realized. As a result, the electrical resistance in the electrical connection between the common electrode layer 125 and the second auxiliary electrode layer 200 or the common electrode layer 125 and the first auxiliary electrode layer 135 is reduced, the light emission efficiency is improved, and the brightness unevenness is suppressed. be able to.

(2) In the display panel 10, the light emitting layer 123 has a configuration in which the light emitting layer 123 is continuously extended in the column direction on the row bank. However, in the above configuration, the light emitting layer 123 may be configured to be intermittent for each pixel on the row bank.
(3) In the display panel 10, the colors of the light emitted by the light emitting layer 123 of the sub-pixel 100se arranged in the gap 522z between the column banks 522Y adjacent to each other in the row direction are configured to be different from each other, and the row banks 122X adjacent to each other in the row direction. The color of the light emitted by the light emitting layer 123 of the sub-pixel 100se arranged in the gap between them is the same. However, in the above configuration, the color of the light emitted by the light emitting layer 123 of the sub-pixel 100se adjacent in the row direction is the same, and the color of the light emitted by the light emitting layer 123 of the sub-pixel 100se adjacent in the column direction is different from each other. May be good. Further, the colors of the light emitted by the light emitting layer 123 of the adjacent sub-pixels 100se in both the matrix directions may be different from each other.

(4) In the display panel 10 according to the embodiment, there are three types of sub-pixels 100se, a red pixel, a green pixel, and a blue pixel, but the present invention is not limited to this. For example, the light emitting layer may be one type, or the light emitting layer may be four types that emit light in red, green, blue, and yellow.
(5) In the above embodiment, the unit pixels 100e are arranged in a matrix, but the present invention is not limited to this. For example, when the interval between the pixel regions is one pitch, it is also effective for a configuration in which the pixel regions are deviated by half a pitch in the column direction between adjacent gaps. In a display panel with increasing definition, it is difficult to visually discriminate a slight deviation in the row direction, and even if the film thickness unevenness is lined up on a straight line (or staggered shape) having a certain width, it is visually band-shaped. Therefore, even in such a case, the display quality of the display panel can be improved by suppressing the uneven brightness from arranging in the staggered pattern.

(6) In the above embodiment, the hole injection layer 120, the hole transport layer 121, the light emitting layer 123, and the electron transport layer 124 are present between the pixel electrode 119 and the common electrode layer 125. Is not limited to this. For example, the hole injection layer 120, the hole transport layer 121, and the electron transport layer 124 may not be used, and only the light emitting layer 123 may exist between the pixel electrode 119 and the common electrode layer 125. Further, for example, a configuration may include a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, and the like, or a configuration including a plurality or all of them at the same time. Further, all of these layers do not have to be made of an organic compound, and may be made of an inorganic substance or the like.

(7) In the above embodiment, the light emitting layer 123 is formed by using a wet film forming process such as a printing method, a spin coating method, or an inkjet method, but the present invention is not limited to this. For example, a dry film forming process such as a vacuum vapor deposition method, an electron beam vapor deposition method, a sputtering method, a reactive sputtering method, an ion plating method, or a vapor phase growth method can also be used. Further, as the material of each constituent part, a known material can be appropriately adopted.

(8) In the above embodiment, the pixel electrode 119, which is an anode, is arranged below the EL element portion, and the pixel electrode 119 is connected to the wiring connected to the source electrode of the TFT. It is also possible to adopt a configuration in which a common electrode layer is arranged at the lower part and an anode is arranged at the upper part. In this case, the cathode arranged at the bottom is connected to the drain in the TFT.

(9) In the above embodiment, a configuration in which two transistors Tr1 and Tr2 are provided for one sub-pixel 100se is adopted, but the present invention is not limited thereto. For example, one transistor may be provided for one subpixel, or three or more transistors may be provided.
(10) In the above embodiment, the top emission type EL display panel is taken as an example, but the present invention is not limited thereto. For example, it can be applied to a bottom emission type display panel or the like. In that case, each configuration can be changed as appropriate.

≪Supplement≫
Each of the embodiments described above shows a preferable specific example of the present invention. Numerical values, shapes, materials, components, arrangement positions and connection forms of components, processes, order of processes, etc. shown in the embodiments are examples, and are not intended to limit the present invention. Further, among the components in the embodiment, the steps not described in the independent claims showing the highest level concept of the present invention will be described as arbitrary components constituting the more preferable form.

Further, the order in which the above steps are executed is for exemplifying for the purpose of specifically explaining the present invention, and may be an order other than the above. Further, a part of the above steps may be executed at the same time (parallel) with other steps.
Further, for the sake of easy understanding of the invention, the scale of the component of each figure given in each of the above embodiments may be different from the actual scale. Further, the present invention is not limited to the description of each of the above embodiments, and can be appropriately modified without departing from the gist of the present invention.

Further, at least a part of the functions of each embodiment and its modifications may be combined.
Further, the present invention also includes various modifications in which modifications within the range that can be conceived by those skilled in the art are made to the present embodiment.

The organic EL display panel and the organic EL display device according to the present invention can be widely used in devices such as television sets, personal computers, mobile phones, and other various electronic devices having a display panel.

1 Organic EL display device 10 Organic EL display panel 100 Organic EL element 100e Unit pixel 100se Sub-pixel 100a Self-luminous area 100b Non-self-luminous area 100x Substrate (TFT substrate)
118 Interlayer Insulation Layer 119 Pixel Electrode 135 Second Auxiliary Electrode Layer 150 Auxiliary Pixel Electrode 200 First Auxiliary Electrode Layer 120 Hole Injection Layer 120A Lower Layer 120B Upper Layer 121 Hole Transport Layer 122 Bank 122X Row Bank 522Y Column Bank 123 Light Emitting Layer 124 Electrons Transport layer 125 Common electrode layer 126 Sealing layer 127 Bonding layer 128 Color filter layer 130 Upper substrate 131 Color filter substrate

Claims (8)

An organic EL display panel in which a plurality of pixel electrodes are arranged in a matrix on a substrate, and a light emitting layer containing an organic light emitting material is arranged on each pixel electrode.
With the board
A plurality of pixel electrodes arranged in a matrix above the substrate,
A first power feeding auxiliary electrode layer extending in a column or row direction in at least one of the gaps of the adjacent pixel electrodes above the substrate.
A second power supply auxiliary electrode layer extending in the same direction as the first power supply auxiliary electrode layer and arranged in a part of the region on the first power supply auxiliary electrode layer.
A plurality of light emitting layers arranged on the plurality of pixel electrodes,
An electron transport layer continuously arranged above the plurality of light emitting layers, covering the upper surface of the first power supply auxiliary electrode layer excluding the partial region and the upper surface of the second power supply auxiliary electrode layer.
A common electrode layer that is continuously arranged so as to cover the upper surface of the electron transport layer is provided.
The first power feeding auxiliary electrode layer contains a first metal as a main component, and the second power feeding auxiliary electrode layer contains a second metal different from the first metal as a main component.
The resistance of the surface layer of the second feeding auxiliary electrode layer is higher than the resistance of the surface layer of the first feeding auxiliary electrode layer.
In the electron transport layer, a missing portion or a partially thinned portion is thinned in the vicinity of the end portion of the first power feeding auxiliary electrode layer and the vicinity of the end portion of the second feeding auxiliary electrode layer. A stratified part is formed,
When the missing portion is formed in the electron transport layer, the common electrode layer is in direct contact with the first feeding auxiliary electrode layer or the second feeding auxiliary electrode layer at the missing portion, and is said to be in direct contact with the second feeding auxiliary electrode layer. When the thinned portion is formed in the electron transport layer, the thinned portion has a lower electrical resistance than the portion other than the thinned portion, and the first power feeding auxiliary electrode layer or the second thinning portion is formed. An organic EL display panel that is electrically connected to the power supply auxiliary electrode layer. The organic EL display panel according to claim 1, wherein a metal oxide film is formed on the surface layer of the second power feeding auxiliary electrode layer. The organic EL display panel according to claim 1, wherein the sheet resistance of the first power feeding auxiliary electrode layer is higher than the sheet resistance of the second power feeding auxiliary electrode layer. The organic EL display panel according to claim 1, wherein the contact resistance between the first feeding auxiliary electrode layer and the common electrode layer is lower than the contact resistance between the second feeding auxiliary electrode layer and the common electrode layer. .. The organic EL display panel according to claim 1, wherein the surface area of the first power feeding auxiliary electrode layer is larger than the surface area of the second power feeding auxiliary electrode layer. The first metal is tungsten, which is
The organic EL display panel according to claim 1, wherein the second metal is aluminum. A method for manufacturing an organic EL display panel in which a plurality of pixel electrodes are arranged in a matrix on a substrate and a light emitting layer containing an organic light emitting material is arranged on each pixel electrode.
A step of forming a plurality of pixel electrodes arranged in a matrix above the substrate by a vapor phase growth method, and
A step of forming a first power feeding auxiliary electrode layer extending in a column or row direction in at least one of the gaps of the adjacent pixel electrodes above the substrate by a vapor phase growth method.
A step of forming a second feeding auxiliary electrode layer extending in the same direction as the first feeding auxiliary electrode layer in a part of the region on the first feeding auxiliary electrode layer by a vapor phase growth method.
A step of forming a plurality of light emitting layers on the plurality of pixel electrodes by a wet film forming method, and
An electron transport layer is continuously formed by a vacuum vapor deposition method above the plurality of light emitting layers, covering the upper surface of the first power feeding auxiliary electrode layer excluding the partial region and the upper surface of the second power feeding auxiliary electrode layer. And the process of
It is provided with a step of continuously forming a common electrode layer by covering the upper surface of the electron transport layer by a sputtering method or a CVD (Chemical Vapor Deposition) method.
In the step of forming the electron transport layer, a partially missing portion or a partially thin layer is formed in the vicinity of the end portion of the first power feeding auxiliary electrode layer and the vicinity of the end portion of the second feeding auxiliary electrode layer. A thinned part is formed,
In the step of forming the common electrode layer, when the missing portion is formed in the electron transport layer, the common electrode layer is the first feeding auxiliary electrode layer or the second feeding auxiliary electrode in the missing portion. When the thinned portion is formed in the electron transport layer by directly contacting the layer, the first power supply assist is performed in the thinned portion with a lower electric resistance than the portion other than the thinned portion. A method for manufacturing an organic EL display panel formed by being electrically connected to an electrode layer or the second power feeding auxiliary electrode layer. The first power feeding auxiliary electrode layer contains a first metal as a main component, and the first metal is tungsten.
The method for manufacturing an organic EL display panel according to claim 7, wherein the second power feeding auxiliary electrode layer contains a second metal different from the first metal as a main component, and the second metal is aluminum. ..

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