JP2009087623A - Manufacturing method of organic el light-emitting element, organic el light-emitting element, and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems wherein when a transparent conductive layer such as ITO and Al added ZnO (ZAO) is used as a positive electrode and the positive electrode is corresponded to three colors R, G, and B, it is necessary to perform sputtering by changing thickness of layers at each of the colors R, G, and B, and it is necessary to perform patterning by a photolithographic etching technique, and it is necessary to repeat a layer-forming photolithographic etching process three times when the thickness of the transparent conductive layer is changed at each light-emitting color, and consequently, lots of materials and man-hours are necessary for the requirements. <P>SOLUTION: After forming a bank section 216, an etching liquid is supplied in the bank section 216 by a liquid-drop discharge method, and etching of the transparent conductive layer is carried out. The thickness of the positive electrodes 23 (R, G, B) is controlled to the thickness suitable to each light-emitting color. The thickness of an island-shaped conductive layer corresponding to each light-emitting color is controlled. Therefore, the thickness of the island-shaped conductive layer can be set up to coincide with wavelength of each light-emitting color in order to improve light-emitting efficiency. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an organic EL light emitting element, an organic EL light emitting element, and an electronic apparatus.

Organic EL light-emitting elements are rapidly spreading as elements that can support various applications as self-luminous elements. For example, in the case of performing color display using an organic EL light emitting element having R, G, B (R: red, G: green, B: blue) light emitting layer, a transparent conductive layer constituting the organic EL light emitting element, HIL By controlling the layer thickness of (hole injection layer), LEP (light emitting polymer), etc., the spectral intensity distribution of the luminescent color can be controlled. Then, by optimizing the thickness of each layer for each of R, G, and B emission colors, light having an ideal spectral intensity distribution can be extracted, and the light emission efficiency can be improved. Among these layers, the thickness of the HIL layer and the IL layer can be easily controlled (evaporation time can be controlled by an evaporation method, and ink concentration and filling amount can be controlled by a droplet discharge method). . With respect to the transparent conductive layer, it is possible to control the layer thickness by performing sputtering by changing the layer thickness for each color of R, G, and B, and performing patterning using a photolithographic etching technique.
Further, Patent Document 1 discloses a method of patterning (drawing) a resist layer by a droplet discharge method and forming a protective film only in a necessary region. If this method is used, etching can be performed in a state where a specific pixel is protected, so that the transparent conductive layer needs to be formed only once. In addition, the entire surface exposure process can be used instead of the mask exposure process, and alignment with the mask pattern for exposure is not required, so that the throughput of the exposure process can be improved.

JP-A-5-338187

When a transparent conductive layer such as ITO or Al-added ZnO (ZAO) is used as the anode and different anode layer thicknesses are adopted for each of the R, G, and B colors, sputtering is performed by changing the layer thickness for each of the R, G, and B colors. It is necessary to perform patterning by a photolithographic etching technique. Thus, when changing the layer thickness of the transparent conductive layer for each luminescent color, it is necessary to repeat the layering (sputtering), photolithography, and etching processes three times, and there is a problem that much material and time are required.
In addition, when the technique described in Patent Document 1 is used, mask alignment during the photolithography process becomes unnecessary, and the photolithography process can be shortened. However, even in this case, it is necessary to repeat the resist baking step and the resist removing step, and a method for forming an organic EL light emitting element more easily is demanded.

SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.
For the sake of convenience, “upper” indicates a direction away from the substrate in accordance with the normal direction from the active surface side of the substrate.

  Application Example 1 An organic EL light emitting device manufacturing method according to this application example includes (1) a step of forming a plurality of island-shaped transparent conductive layers located on a substrate and (2) an island shape. Forming a bank in a region surrounding the transparent conductive layer, and (3) selectively supplying an etching solution for etching the island-shaped transparent conductive layer into a part of the bank, A step of performing etching under conditions where the transparent conductive layer remains; (4) a step of performing the step (3) once or a plurality of times; and (5) a light emitting layer on each island-shaped transparent conductive layer. And a step of forming a functional layer.

  According to this application example, the etching solution is supplied to the island-like conductive layers located in some banks. Since the island-shaped conductive layer located in the bank to which the etching solution is supplied is selectively etched, the thickness of the island-shaped conductive layer in each region can be controlled. Further, by performing this process a plurality of times, the thickness of the island-like conductive layer can be set in multiple stages. Therefore, the thickness of the island-like conductive layer can be set in accordance with the wavelength of each emission color, and the light emission efficiency can be improved.

  Application Example 2 In the method for manufacturing an organic EL light emitting device according to the application example, a droplet discharge method is used as means for supplying the etching solution in the step (3).

  According to the application example described above, the etching solution can be supplied with high positional accuracy and the amount of the etching solution can be supplied with high accuracy so that the etching solution is supplied only into each selected bank. .

  [Application Example 3] In the method of manufacturing an organic EL light emitting device according to the application example described above, the rinsing process is performed at the same time that the etching amount performed by the etching solution supplied in (3) reaches a predetermined amount. The etching solution is diluted and discharged to stop the etching.

  According to the application example described above, it is possible to control the thickness of the island-shaped conductive layer. When the etching amount reaches the set amount, the rinsing process is performed and the etching solution is diluted and discharged, so that the etching solution supplied in each bank is diluted at the same timing, so that the island-like conductive layer to which the etching solution is supplied The etching amount can be made uniform.

  Application Example 4 In the method of manufacturing an organic EL light emitting device according to the application example, the discharge timing of the etching solution supplied in (3) is controlled, and the etching solution is discharged into the bank at a plurality of timings. Etching is performed by changing the residence time of the etchant in each bank, and when the etching amount reaches a predetermined amount, the substrate is rinsed, and the etchant is diluted and discharged. Etching is stopped.

  According to the application example described above, the etching solution is discharged into each bank at a plurality of discharge timings. By changing the discharge timing, the residence time of the etchant on the island-like conductive layer can be changed. When the etching amount reaches the set amount and the rinsing process is performed and the etching solution is diluted and discharged, the etching can be performed to a plurality of depths associated with the discharge timing.

  Application Example 5 In the method of manufacturing an organic EL light emitting device according to the application example, the bank is formed by discharging an etchant having a plurality of reaction speeds into the bank supplied in (3). Etching is performed so that the etching amount with the etching solution at a plurality of levels at each time, and the etching amount of each of the transparent conductive layers reaches a predetermined amount, and at the same time, the substrate is rinsed, and the etching is performed. The etching is stopped by diluting and discharging the liquid.

  According to the application example described above, an etching solution having a plurality of etching rates is discharged into each bank. By providing a plurality of etching rates, the etching depth with the island-like conductive layer can be changed. When the etching amount of each island-like conductive layer reaches the set amount, the rinsing process is performed and the etching solution is diluted and discharged, so that the etching can be performed to a plurality of levels associated with the etching rate.

  Application Example 6 In the method for manufacturing an organic EL light emitting device according to the application example, the amount of the etching solution supplied in (3) is an amount corresponding to a predetermined etching amount of the island-shaped transparent conductive layer. The etching is stopped by reducing the active substance of the etching solution.

  According to the application example described above, the etching liquid is discharged into each bank with a plurality of discharge amounts. By changing the discharge amount, the etching amount of the island-like conductive layer is etched until the active substance in the etching solution is lost. Therefore, it is possible to perform etching to a plurality of levels associated with the discharge amount of the etching solution.

  Application Example 7 An organic EL light emitting device according to this application example is manufactured using the method for manufacturing an organic EL light emitting device described above.

  According to this application example, the manufacturing process is shortened. Therefore, it is possible to suppress the occurrence of defects having a strong correlation with the number of manufacturing processes, and it is possible to provide an organic EL light emitting element having high reliability. In addition, since the number of manufacturing steps can be reduced, the manufacturing cost can be reduced.

  Application Example 8 An electronic apparatus according to this application example includes the above-described organic EL light emitting element.

  According to this application example, since the electronic apparatus using the organic EL light emitting element with high reliability is provided, the display characteristics are maintained with high reliability by configuring the display unit using the organic EL light emitting element. Electronic devices can be provided.

(Configuration of organic EL display)
Hereinafter, in the present embodiment, a configuration of an organic EL display including an organic EL light emitting element obtained by using a method for manufacturing an organic EL light emitting element will be described with reference to the drawings.

  FIG. 1 is a schematic diagram showing a wiring structure of an organic EL display. This organic EL display 1 is of an active matrix type using thin film transistors (hereinafter referred to as TFTs) as switching elements, and intersects a plurality of scanning lines 101 at right angles to each scanning line 101. It has a wiring configuration comprising a plurality of signal lines 102 extending in the direction and a plurality of power supply lines 103 extending in parallel with each signal line 102, and pixels (subpixels 40) near each intersection of the scanning line 101 and the signal line 102. ) Is provided.

A data line driving circuit 100 including a shift register, a level shifter, a video line, and an analog switch is connected to the signal line 102. Further, a scanning line driving circuit 80 including a shift register and a level shifter is connected to the scanning line 101.
Each of the sub-pixels 40 holds a switching TFT 122 in which a scanning signal is supplied to the gate electrode via the scanning line 101 and a pixel signal shared from the signal line 102 via the switching TFT 122. A driving current is applied from the power source line 103 when the capacitor 113, the driving TFT 123 to which the pixel signal held by the holding capacitor 113 is supplied to the gate electrode, and the power source line 103 through the TFT 123 are electrically connected. The pixel electrode (anode) 23, the counter electrode (cathode) 50 at a position facing the pixel electrode (anode) 23, and the pixel electrode (anode) 23 and the counter electrode (cathode) 50. Organic EL light emitting elements 17 (R, G, B) (R (red), G (green), B (blue)) are provided.

Next, a specific aspect of the organic EL display 1 of the present embodiment will be described with reference to FIG. Here, FIG. 2 is a plan view schematically showing the configuration of the organic EL display 1.
As shown in FIG. 2, in the actual display area 4 on the substrate 20A, sub-pixels 40 provided corresponding to R, G, and B are regularly arranged in a matrix. Here, the substrate 20 </ b> A includes a substrate body 20 and, for example, a buffer layer 21 (see FIG. 3) provided on the substrate body 20.

The sub-pixels 40 (R, G, B) of R, G, and B colors constitute a display unit pixel 41 as one basic unit. Each of the sub-pixels 40 (R, G, B) is an organic EL light emitting element corresponding to red light emission (R), green light emission (G), and blue light emission (B) in accordance with the operation of the TFTs 122, 123. 17 (R, G, B) (see FIG. 1). Thus, the display unit pixel 41 has a configuration for performing full color display by mixing R, G, and B light emission.
In the present embodiment, the pixel unit 3 includes an actual display area 4 in the center (within the two-dot chain line in the figure) and a dummy area 5 (one-dot chain line and two-dot chain line) arranged around the actual display area 4. Between the two areas). Further, scanning line driving circuits 80 are arranged on both sides of the actual display region 4 in FIG. The scanning line driving circuit 80 is provided on the lower layer side of the dummy region 5.

  Further, an inspection circuit 90 is disposed above the actual display area 4 in FIG. 2, and the inspection circuit 90 is disposed on the lower layer side of the dummy area 5. The inspection circuit 90 is a circuit for inspecting the operating state of the organic EL display 1, and includes, for example, inspection information output means (not shown) for outputting inspection results to the outside, It is configured so that the quality and defect inspection of the EL display can be performed.

(Structure of organic EL light emitting device)
Next, the structure of the organic EL light emitting device will be described with reference to FIG. FIG. 3 is a schematic cross-sectional view of the organic EL light emitting element 17 (R, G, B) constituting the organic EL display 1 (see FIG. 1).

For example, on the substrate 20A on which the buffer layer 21 containing silicon nitride or the like is formed on the substrate body 20, the first bank portion 216a made of SiO ₂ or the like is formed on the first bank portion 216a. A bank part 216 composed of a second bank part 216b made of acrylic or the like is disposed. Here, the first bank part 216 a is formed so as to run on the peripheral edge of the pixel electrode (anode) 23.

  In the bank part 216, an optically transparent anode 23 (R, G, B) made of ITO or the like is disposed. The layer thickness of the anode 23 is different for each color of the organic EL light emitting element 17 (R, G, B), and the layer thickness is as follows: anode 23R> anode 23G> anode 23B. Specifically, the anode 23R has a layer thickness of about 120 nm, the anode 23G has a layer thickness of about 60 nm, and the anode 23B has a layer thickness of about 40 nm.

  The functional layer 210R constituting the red organic EL light emitting element 17R includes a hole injection / transport layer 211R and a light emitting layer 212R. The hole injection / transport layer 211R is formed of, for example, a mixture of polyaniline and polystyrene sulfonic acid (PSS). Specifically, 0.7% by weight of a mixture of this polyaniline and PSS is 50% by weight of water, 50% by weight of diethylene glycol (DEG), and 0.1% by weight of a surfactant (for example, Sunfinol 61 [trade name]) ( The total number is not 100% for the convenience of significant figures) and is dispersed in a dispersion medium mixed to be used as a liquid material for forming the hole injection / transport layer 211R.

In addition, the hole injection / transport layer 211R of the red organic EL light emitting element 17R is not limited to the above-mentioned mixture of polyaniline and polystyrene sulfonic acid. As a derivative, a mixture of 3,4-polyethylenedioxythiophene (PEDOT) and polystyrene sulfonic acid (PSS) can be used as a main component. Also in this case, this is dispersed in the dispersion medium (water / DEG / surfactant) to obtain a liquid material. By using this material and forming a layer using a droplet discharge method, the hole injection / transport layer 211R can be formed.
Here, the mixture of 3,4-polyethylenedioxythiophene (PEDOT) and polystyrene sulfonic acid (PSS) becomes a state in which PEDOT is bonded in a long chain made of PSS, and this is dispersed in a dispersion medium, whereby gel perch. It becomes Kuru. This gel particle can be mechanically crushed and dispersed to adjust the average particle size, and the layer obtained by adjusting the average particle size (hole injection / transport layer 211R). It is possible to adjust the resistance value.

When a mixture of PEDOT and PSS is used as the main component of the forming material for the hole injection / transport layer 211R of the red organic EL light emitting element 17R, the blending ratio (weight ratio) of PEDOT and PSS is set to 1:10. 1:15 or so. By this treatment, the resistance value of the obtained hole injection / transport layer 211R can be adjusted.
For the light emitting layer 212R in the red organic EL light emitting element 17R, CN-PPV shown as the following compound 1 is preferably used as the forming material.

この化合物１は、例えばシクロヘキシルベンゼン（ＣＨＢ）とイソプロピルビフェニル（ＩＰＢＰ）とを１：１で混合した溶媒に対して、０．９重量％程度となるように配合され溶解されることにより、発光層２１２Ｒ形成用の液状材料とされる。そして、この液状材料が後述するように液滴吐出法で正孔注入／輸送層２１１Ｒ上に配置され、発光層２１２Ｒが形成されている。なお、前記ＣＮ−ＰＰＶを用いた液状材料は、正孔注入／輸送層２１１Ｒとして前述したものに対して用いることができる。
そして、機能層２１０Ｒは、層厚が８０ｎｍ程度となるよう構成される。この程度の層厚を用いることで赤色の光が共振作用により強調され、赤色の有機ＥＬ発光素子１７Ｒの発光効率と色純度を向上させることができる。そして、発光層２１２Ｒ上には、Ｒ，Ｇ，Ｂ共通の電極として例えばストロンチウム（Ｓｒ）を介してアルミニウム（Ａｌ）を用いてなる陰極２１４が形成される。
緑色の有機ＥＬ発光素子１７Ｇを構成する機能層２１０Ｇは、正孔注入／輸送層２１１Ｇと、発光層２１２Ｇと、を含む。
緑色の有機ＥＬ発光素子１７Ｇは、その正孔注入／輸送層２１１Ｇが、前記ＰＥＤＯＴとＰＳＳとの混合物によって形成されている。緑色の有機ＥＬ発光素子１７Ｇの正孔注入／輸送層２１１Ｇ形成に用いられる主成分としては、ＰＥＤＯＴとＰＳＳとの配合比（重量比）を１：３０程度としたものが好適に用いられる。また、正孔注入／輸送層２１１Ｇ用を形成する材料の主成分としては、他に例えば、ＰＥＤＯＴとＰＳＳとの配合比（重量比）を１：２０程度としたものも好適に用いられる。これら混合物にあっても、配合量として０．７重量％が前記の分散媒（水；５０重量％／ＤＥＧ；５０重量％／界面活性剤；０．１重量％）（有効数字の都合上、合計は１００％となっていない）に分散されて液状材料とされる。この材料を使い、液滴吐出法で層形成することにより、正孔注入／輸送層２１１Ｇとなる。
緑色の有機ＥＬ発光素子１７Ｇの発光層２１２Ｇは、その形成材料として、以下の化合物２として示すＦ８ＢＴと化合物３として示すＴＦＢとを、１：１に混合したものが好適に用いられる。

This compound 1 is blended and dissolved so as to be about 0.9% by weight with respect to a solvent in which cyclohexylbenzene (CHB) and isopropylbiphenyl (IPBP) are mixed at a ratio of 1: 1, for example. The liquid material for forming 212R is used. Then, as will be described later, this liquid material is disposed on the hole injection / transport layer 211R by a droplet discharge method to form a light emitting layer 212R. The liquid material using CN-PPV can be used for the hole injection / transport layer 211R described above.
The functional layer 210R is configured to have a layer thickness of about 80 nm. By using such a layer thickness, red light is emphasized by the resonance action, and the luminous efficiency and color purity of the red organic EL light emitting element 17R can be improved. On the light emitting layer 212R, a cathode 214 made of aluminum (Al) through, for example, strontium (Sr) is formed as a common electrode for R, G, and B.
The functional layer 210G constituting the green organic EL light emitting element 17G includes a hole injection / transport layer 211G and a light emitting layer 212G.
In the green organic EL light emitting element 17G, the hole injection / transport layer 211G is formed of a mixture of the PEDOT and the PSS. As the main component used for forming the hole injecting / transporting layer 211G of the green organic EL light emitting element 17G, a compounding ratio (weight ratio) of PEDOT and PSS of about 1:30 is preferably used. Further, as the main component of the material forming the hole injection / transport layer 211G, for example, a material in which the blending ratio (weight ratio) of PEDOT and PSS is about 1:20 is also preferably used. Even in these mixtures, 0.7% by weight as a blending amount is the above dispersion medium (water; 50% by weight / DEG; 50% by weight / surfactant; 0.1% by weight) (for the convenience of effective figures, The total is not 100%) and is made into a liquid material. By using this material and forming a layer by a droplet discharge method, a hole injection / transport layer 211G is formed.
For the light emitting layer 212G of the green organic EL light emitting element 17G, a material in which F8BT shown as the following compound 2 and TFB shown as the compound 3 are mixed in a 1: 1 ratio is preferably used.

これら化合物２と化合物３とを含む混合物は、前記のＣＨＢとＩＰＢＰとを１：１で混合した溶媒に対して、０．８重量％程度となるように配合され溶解されることにより、発光層２１２Ｇ形成用の液状材料とされる。そして、この液状材料が液滴吐出法を用いて正孔注入／輸送層２１１Ｇ上に配置されることにより、発光層２１２Ｇが形成されている。なお、前記の混合物を用いた液状材料は、正孔注入／輸送層２１１Ｇとして前述したものに対して用いることができる。
そして、機能層２１０Ｇは、層厚が８０ｎｍ程度となるよう構成される。この程度の層厚を用いることで緑色の光が共振作用により強調され、緑色の有機ＥＬ発光素子１７Ｇの発光効率と色純度を向上させることができる。そして、発光層２１２Ｇ上には、Ｒ，Ｇ，Ｂ共通の電極として、発光層２１２Ｒと同様にストロンチウム（Ｓｒ）を介してアルミニウム（Ａｌ）を用いてなる陰極２１４が形成される。
青色の有機ＥＬ発光素子１７Ｂを構成する機能層２１０Ｂは、正孔注入／輸送層２１１Ｂと、発光層２１２Ｂと、電子注入／輸送層２１３Ｂと、を含む。
有機ＥＬ発光素子１７Ｂの正孔注入／輸送層２１１Ｂは、その形成材料として、以下の化合物４として示すＦ８（ポリジオクチルフルオレン）が好適に用いられる。

The mixture containing the compound 2 and the compound 3 is blended and dissolved so as to be about 0.8% by weight with respect to the solvent in which the CHB and IPBP are mixed at a ratio of 1: 1. The liquid material for forming 212G is used. The liquid material is disposed on the hole injection / transport layer 211G using a droplet discharge method, thereby forming the light emitting layer 212G. The liquid material using the above mixture can be used for the hole injection / transport layer 211G described above.
The functional layer 210G is configured to have a layer thickness of about 80 nm. By using such a layer thickness, the green light is emphasized by the resonance action, and the light emission efficiency and color purity of the green organic EL light emitting element 17G can be improved. On the light emitting layer 212G, a cathode 214 made of aluminum (Al) is formed as an electrode common to R, G, and B through strontium (Sr) in the same manner as the light emitting layer 212R.
The functional layer 210B constituting the blue organic EL light emitting element 17B includes a hole injection / transport layer 211B, a light emitting layer 212B, and an electron injection / transport layer 213B.
For the hole injection / transport layer 211B of the organic EL light emitting element 17B, F8 (polydioctylfluorene) shown as the following compound 4 is preferably used as a forming material thereof.

この化合物４も、前記のＣＨＢとＩＰＢＰとを１：１で混合した溶媒に対して、０．８重量％程度となるように配合され溶解されることにより、発光層２１２Ｂ形成用の液状材料とされる。そして、この液状材料が液滴吐出法で正孔注入／輸送層２１１Ｂ上に配置されることにより、発光層２１２Ｂが形成されている。
電子注入／輸送層２１３Ｂは、有機金属化合物、特にこの有機金属化合物中の金属の仕事関数が３．０ｅＶ以下であるものが好ましく、具体的には以下の化合物５として示すＬｉキノリロールからなっている。

This compound 4 is blended and dissolved so as to be about 0.8% by weight with respect to the solvent in which CHB and IPBP are mixed at a ratio of 1: 1, whereby a liquid material for forming the light emitting layer 212B is obtained. Is done. The liquid material is disposed on the hole injection / transport layer 211B by a droplet discharge method, whereby the light emitting layer 212B is formed.
The electron injecting / transporting layer 213B is preferably an organometallic compound, particularly one having a work function of a metal in the organometallic compound of 3.0 eV or less, and specifically composed of Li quinololol as compound 5 below. .

有機金属化合物は、一般に有機溶剤によって溶解し、液状材料となる。したがって、このような液状材料を例えば液滴吐出法で吐出することで電子注入／輸送層２１３Ｂが得られる。なお、この電子注入／輸送層２１３Ｂは発光層２１２Ｂ上に形成されることから、この発光層２１２Ｂを再溶解させないよう、Ｌｉキノリロールを溶解させる溶剤としては極性溶剤が用いられる。具体的には、ジエチレングリコールモノメチルエーテルと１，３−ジメチルイミダゾリジノンとを１：１で混合してなる混合溶媒が好適に用いられ、この混合溶媒に対してＬｉキノリロールが約０．０５重量％配合されることにより、液状材料が形成される。
なお、電子注入／輸送層２１３Ｂの形成材料としては、前記Ｌｉキノリロール以外にも種々の有機金属が使用可能であり、例えば以下の化合物６として示すヘキサフルオロアセチルアセトナートリチウムも好適に用いられる。

The organometallic compound is generally dissolved in an organic solvent to form a liquid material. Accordingly, the electron injection / transport layer 213B is obtained by discharging such a liquid material by, for example, a droplet discharge method. Since the electron injection / transport layer 213B is formed on the light emitting layer 212B, a polar solvent is used as a solvent for dissolving the Li quinololol so as not to redissolve the light emitting layer 212B. Specifically, a mixed solvent obtained by mixing diethylene glycol monomethyl ether and 1,3-dimethylimidazolidinone in a ratio of 1: 1 is preferably used, and Li quinolol is about 0.05% by weight with respect to the mixed solvent. By blending, a liquid material is formed.
As a material for forming the electron injection / transport layer 213B, various organic metals can be used in addition to the Li quinololol. For example, hexafluoroacetylacetonate lithium shown as the following compound 6 is also preferably used.

このような電子注入／輸送層２１３Ｂを備えることによって青色の発光をなす有機ＥＬ発光素子１７Ｂは、対向電極（陰極）１２から注入された電子が電子注入／輸送層２１３Ｂを介して良好に発光層２１２Ｂに注入され、正孔と再結合することから、より良好に発光をなすようになっている。

By providing such an electron injection / transport layer 213B, the organic EL light emitting element 17B that emits blue light has a good light emission layer in which electrons injected from the counter electrode (cathode) 12 are transmitted through the electron injection / transport layer 213B. Since it is injected into 212B and recombined with holes, it emits light better.

  The functional layer 210B is configured to have a layer thickness of about 60 nm. By using such a layer thickness, blue light is emphasized by the resonance action, and the light emission efficiency and color purity of the blue organic EL light emitting element 17B can be improved. Then, on the electron injection / transport layer 213B, a bottom emission is formed in which a cathode 214 made of aluminum (Al) through strontium (Sr) is formed as an electrode common to R, G, and B, similarly to the light emitting layer 212R. It has a mold configuration. This can be easily applied to the top emission type by changing the electrode arrangement or the like.

  Further, the example in which the light emitting layer 212 (R, G, B) having a different emission wavelength for each color is used as the functional layer 210 (R, G, B) has been described. A functional layer having a structure that separates R, G, and B light using a color filter or the like after obtaining white light by emitting light from one element may be used. In particular, when white light is emitted, the emission wavelength varies sensitively with respect to the thickness of the functional layer 210 (R, G, B) and the thickness of the anode 23 (R, G, B). is there.

(First manufacturing method of organic EL light emitting device)
Next, a first manufacturing method for changing the thickness of the anode 23 (R, G, B) for each color will be described with reference to FIGS. 4 (a) to 4 (d) and FIG. 3. The anode 23 is formed by the following procedure using, for example, ITO, aluminum-added ZnO (ZAO), or gallium-added zinc oxide (GZO).

  First, as step 1, a buffer layer 21 using silicon nitride or the like is formed on the substrate body 20. The thickness of the buffer layer 21 is, for example, about 50 nm. Here, a combination of the substrate body 20 and the buffer layer 21 is referred to as a substrate 20A. Next, an anode layer (not shown) is formed by sputtering using, for example, ITO as a target. Here, the thickness of the anode layer is preferably about 120 nm as a thickness suitable for red light emission. In this case, it is not necessary to reset the thickness suitable for red light emission by etching, thereby reducing the number of steps. Can do. Then, the anode precursor is etched in a matrix through a photolithography / etching step to form an anode precursor 23A as an island-shaped transparent conductive layer. The structure shown in FIG. 4A is formed through the steps so far.

Next, as step 2, a first bank precursor (not shown) is formed using, for example, SiO _2, and a first bank portion 216a is formed through a photolithographic etching step. The thickness of the first bank unit 216a is, for example, about 50 nm. Similarly, the second bank portion 216b is formed using, for example, an acrylic resin having excellent heat resistance and solvent resistance. The thickness of the second bank part 216b is, for example, about 2 μm. Through the steps so far, the structure shown in FIG. 4B is formed. Here, a combination of the first bank unit 216a and the second bank unit 216b is referred to as a bank unit 216.

  Next, as Step 3, an etching solution 215 is discharged to the region of the anode 23 (G, B) in order to change the thickness of the anode 23 (R, G, B) using a droplet discharge method. In this case, since the organic EL light emitting element 17 (R, G, B) is separated by the first bank part 216a and the second bank part 216b, the penetration of the etching solution 215 into the adjacent organic EL light emitting element 17 is suppressed. Therefore, the thickness of the anode 23 (R, G, B) can be controlled more precisely. FIG. 4C shows a state where the etching solution 215 is injected and the etching is advanced.

Next, as Step 4, after the etching solution 215 is discharged to the area of the anode 23 (G, B), the thickness of the anode 23G becomes a thickness suitable for G (green) emission (for example, about 60 nm). At that time, the substrate 20A is treated with, for example, ultrapure water, and the etching solution 215 is diluted and removed. After completion of dilution removal, the substrate 20A is dried. Then, an etching solution 215 is discharged to the region of the anode 23B. FIG. 4D shows a state in which the etching solution 215 has been discharged and etching has progressed. Then, when the thickness of the anode 23B reaches a thickness suitable for B (blue) emission (for example, 40 nm), the substrate 20A is treated with, for example, ultrapure water, the etching solution 215 is diluted and removed, and dried. Let
By using this step, the thickness of the anode 23 (R, G, B) can be controlled to a thickness suitable for each emission color.

Next, as step 5, the functional layer 210 including the light emitting layer 212 described above is formed using a droplet discharge method, a vacuum deposition method, or the like, and a cathode 214 is further formed. By using this step, it is possible to obtain the organic EL light emitting element 17 (R, G, B) having high color purity and having an efficient light emission intensity for each color.
In this embodiment, the anode 23 (G, B) is once etched and 23B is etched again. However, this may be performed by etching the anode 23G and then etching the anode 23B. good.

(Second manufacturing method of organic EL light emitting device)
Next, a second manufacturing method for changing the thickness of the anode 23 (R, G, B) for each color will be described with reference to FIGS. First, step 1 and step 2 described above are performed.

  Next, the etching solution 215 is discharged to the region of the anode 23B by a droplet discharge method. FIG. 5A shows a state where etching has progressed with the etching solution 215. Then, the etching solution 215 is discharged to the region of the anode 23G with a time difference. FIG. 5B shows a state where etching has progressed with the etching solution 215. Then, the layer thickness of each of the anode 23B and the anode 23G becomes about 40 nm for the anode 23B and about 60 nm for the anode 23G. At the same time, the substrate 20A is treated with, for example, ultrapure water to dilute and remove the etching solution 215. After completion of dilution removal, the substrate 20A is dried.

  Then, by performing step 5 described above, the functional layer 210 (R, G, B) including the light emitting layer 212 (R, G, B) shown in FIG. The cathode 214 is formed. By using this step, it is possible to obtain the organic EL light emitting device 1 having high color purity and having an efficient light emission intensity for each color.

(Third manufacturing method of organic EL light emitting device)
Next, a third manufacturing method for changing the thickness of the anode 23 (R, G, B) for each color will be described with reference to FIGS. First, step 1 and step 2 described above are performed.

  Next, an etching solution 215a is prepared by diluting the etching solution 215 with a stock solution and ultrapure water and reducing the etching rate. The etching solution 215 is discharged to the area of the anode 23B by a droplet discharge method. Discharge to 23G area. This process is shown in FIG.

  Next, as shown in FIG. 6B, after the etching has progressed to a thickness of the anode 23G of about 60 nm and a thickness of the anode 23B of about 40 nm, the substrate 20A is treated with, for example, ultrapure water, etc. Then, the etching solution 215a is diluted and removed. After completion of dilution removal, the substrate 20A is dried.

  Then, by performing step 5 described above, the functional layer 210 (R, G, B) including the light emitting layer 212 (R, G, B) shown in FIG. The cathode 214 is formed. By using this step, it is possible to obtain the organic EL light emitting device 1 having high color purity and having an efficient light emission intensity for each color.

(The 4th manufacturing method of an organic electroluminescent light emitting element)
Next, a fourth manufacturing method for changing the thickness of the anode 23 (R, G, B) for each color will be described with reference to FIGS. First, the above steps 1 and 2 are performed.

  Next, as shown in FIG. 7A, a small amount of an etching solution 215 is dropped onto the anode 23G region by a droplet discharge method, and the etching solution is about 20% larger than the anode 23G region in the anode 23B region. 215 is added dropwise. Since the discharge amount of the etching solution 215 is small, the reactive species for etching the anode 23B and the anode 23G are used up, and the etching is finished in a state where the etching solution 215 is changed to the consumable etching solution 215b. This state is shown in FIG.

  Then, by performing step 5 described above, the functional layer 210 (R, G, B) including the light emitting layer 212 (R, G, B) shown in FIG. The cathode 214 is formed. By using this step, it is possible to obtain the organic EL light emitting device 1 having high color purity and having an efficient light emission intensity for each color.

(Example of mounting on electronic equipment)
Next, an electronic device using the above manufacturing method will be described. 8A to 8C illustrate an example of mounting an electronic device including the organic EL display 1 using the organic EL light emitting element 17 (R, G, B) shown in FIG. 3 described above. FIG. 8A shows a configuration of a mobile personal computer including the organic EL display 1. The personal computer 2000 includes the organic EL display 1 and a main body 2010. The main body 2010 is provided with a power switch 2001 and a keyboard 2002. FIG. 8B shows a configuration of a mobile phone provided with the organic EL display 1. The cellular phone 3000 includes a plurality of operation buttons 3001, scroll buttons 3002, and the organic EL display 1 as a display unit. By operating the scroll button 3002, the screen displayed on the organic EL display 1 is scrolled. FIG. 8C shows a configuration of a portable information terminal (PDA: Personal Digital Assistants) to which the organic EL display 1 is applied. The information portable terminal 4000 includes a plurality of operation buttons 4001, a power switch 4002, and the organic EL display 1 as a display unit. When the power switch 4002 is operated, various types of information such as an address book and a schedule book are displayed on the organic EL display 1.

  In addition, as an electronic device on which the organic EL display 1 is mounted, in addition to the one shown in FIG. 8, a digital still camera, a liquid crystal television, a viewfinder type, a monitor direct view type video tape recorder, a car navigation device, a pager, an electronic notebook, Examples include a calculator, a word processor, a workstation, a videophone, a POS terminal, and a device equipped with a touch panel. And the organic EL display 1 mentioned above is applicable as a display part of these various electronic devices.

The schematic diagram which shows the wiring structure of an organic electroluminescent display. The top view which shows the structure of an organic electroluminescent display typically. The schematic cross section of the organic electroluminescent light emitting element which comprises an organic electroluminescent display. (A)-(d) is process sectional drawing which shows the 1st manufacturing method of an organic electroluminescent light emitting element. (A)-(b) is process sectional drawing which shows the 2nd manufacturing method of an organic electroluminescent light emitting element. (A)-(b) is process sectional drawing which shows the 3rd manufacturing method of an organic electroluminescent light emitting element. (A)-(b) is process sectional drawing which shows the 4th manufacturing method of an organic electroluminescent light emitting element. (A)-(c) is the mounting example of the electronic device containing the organic EL display using the organic EL light emitting element.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Organic EL display, 3 ... Pixel part, 4 ... Real display area, 5 ... Dummy area, 17 ... Organic EL light emitting element, 17B ... Organic EL light emitting element, 17G ... Organic EL light emitting element, 17R ... Organic EL light emitting element, DESCRIPTION OF SYMBOLS 20 ... Substrate body, 20A ... Substrate, 21 ... Buffer layer, 23 ... Anode, 23A ... Anode precursor, 23B ... Anode, 23G ... Anode, 23R ... Anode, 40 ... Subpixel, 41 ... Display unit pixel, 61 ... Sanfinol , 80: Scanning line driving circuit, 90: Inspection circuit, 100: Data line driving circuit, 101: Scanning line, 102: Signal line, 103 ... Power supply line, 113: Retention capacitor, 122 ... TFT, 123 ... TFT, 210 ... Functional layer, 210B ... functional layer, 210G ... functional layer, 210R ... functional layer, 211B ... hole injection / transport layer, 211G ... hole injection / transport layer, 211R ... hole injection / transport layer 212 ... Light emitting layer, 212B ... Light emitting layer, 212G ... Light emitting layer, 212R ... Light emitting layer, 213B ... Electron injection / transport layer, 214 ... Cathode, 215 ... Etching solution, 215a ... Etching solution, 215b ... Consumable etching solution, 216 ... Bank part, 216a ... 1st bank part, 216b ... 2nd bank part, 2000 ... Personal computer, 2001 ... Power switch, 2002 ... Keyboard, 2010 ... Main part, 3000 ... Mobile phone, 3001 ... Operation button, 3002 ... Scroll button 4000 ... portable information terminal, 4001 ... operation button, 4002 ... power switch.

Claims (8)

(1) a step of forming a plurality of island-shaped transparent conductive layers located on the substrate;
(2) forming a bank in a region surrounding the island-shaped transparent conductive layer;
(3) a step of selectively supplying an etching solution for etching the island-shaped transparent conductive layer into a part of the banks, and performing etching under conditions where the island-shaped transparent conductive layer remains;
(4) a step of performing the above (3) once or a plurality of times;
(5) forming a functional layer including a light emitting layer on each island-like transparent conductive layer;
The manufacturing method of the organic electroluminescent light emitting element characterized by including.   2. The method of manufacturing an organic EL light emitting device according to claim 1, wherein a droplet discharge method is used as means for supplying the etching solution in the step (3). .   It is a manufacturing method of the organic electroluminescent light emitting element of Claim 1 or 2, Comprising: The rinse amount is performed simultaneously with the etching amount performed with the said etching liquid supplied by said (3) reaching a predetermined amount. A method of manufacturing an organic EL light emitting device, wherein the etching is stopped by diluting and discharging the etching solution.   3. The method of manufacturing an organic EL light emitting device according to claim 1, wherein the etching timing of the etching solution supplied in (3) is controlled, and the etching solution is discharged into the bank at a plurality of timings. Etching is performed by changing the residence time of the etchant in each bank, and when the etching amount reaches a predetermined amount, the substrate is rinsed, and the etchant is diluted and discharged. Etching is stopped, The manufacturing method of the organic electroluminescent light emitting element characterized by the above-mentioned.   3. The method of manufacturing an organic EL light-emitting device according to claim 1, wherein the bank is formed by discharging an etchant having a plurality of reaction speeds into the bank supplied in (3). Etching is performed so that the etching amount with the etching solution at a plurality of levels at each time, and the etching amount of each of the transparent conductive layers reaches a predetermined amount, and at the same time, the substrate is rinsed, and the etching is performed. A method for producing an organic EL light emitting device, comprising diluting and discharging a liquid to stop etching.   3. The method of manufacturing an organic EL light emitting device according to claim 1, wherein the amount of the etching solution supplied in (3) is an amount corresponding to a predetermined etching amount of the island-shaped transparent conductive layer. The method of manufacturing an organic EL light emitting device is characterized in that the etching is stopped when the active substance of the etching solution is reduced.   It manufactures using the manufacturing method of the organic EL light emitting element as described in any one of Claims 1 thru | or 6. The organic EL light emitting element characterized by the above-mentioned.   An electronic device comprising the organic EL light emitting device according to claim 7.

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