JPH10247587A - Organic electroluminescence display and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a long-life and inexpensive organic EL display which has a positive electrode, an organic functional layer containing a luminescent layer, and a negative electrode on its board surface, and provide a method in which the negative electrode and a terminal electrode are certainly connected each other without exchanging masks during forming the organic functional layer and the negative electrode sequentially. SOLUTION: A protection layer 7 which consists of a conductive inorganic material layer 71 and an organic protection layer 72 is placed on a negative electrode 6. The organic protection layer 72 is formed using carbon fluoride polymer which contains chloride by a vacuum deposition method or a spatter method. The conductive inorganic material layer 71 is made of conductive inorganic material such as Al or TiN. By forming the conductive inorganic material layer 71 in a method which provides well step-coating property than the method used for forming an organic functional layer 5, the conductive inorganic material layer 71 contacts with at least part of a terminal electrode 3, and the negative electrode 6 is connected with the terminal electrode 3 electrically.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescence (E) device used for a display or a light source.
L) A display device and a method for manufacturing the same.

[0002]

2. Description of the Related Art An organic EL device is a device having a basic structure in which an anode, an organic functional layer including a light emitting layer, and a cathode are laminated on a substrate made of glass or the like.

Display devices using organic EL elements have the following advantages over liquid crystal displays, which are currently the mainstream flat panel displays.

1) Wide viewing angle due to self-emission 2) A display with a thickness of 2 to 3 mm can be easily manufactured 3) Emission color is natural because no polarizing plate is used 4) The display must be clear and vivid due to the wide dynamic range of light and dark. 5) Operate in a wide temperature range. 6) The response speed is three orders of magnitude faster than that of liquid crystal, so that moving images can be displayed easily. 7) Extremely high brightness of several hundreds to 1,000 cd / cm ² can be obtained with a voltage of about 10 V

As a metal material used as a cathode of an organic EL display device, a material capable of injecting a large amount of electrons into a light emitting layer is considered to be effective. In other words, a material having a lower work function is more suitable for the cathode. There are various materials having a low work function. The metal having the lowest work function is an alkali metal. However, since the alkali metal is unstable in air, it is difficult to use the metal as a cathode of an organic EL display device. For this reason, low work function materials other than alkali metals have been proposed as cathode materials for EL display devices. Specifically, for example, there are alloys such as Ag.Mg and In.Mg described in JP-A-2-15595, and an alkali metal or an alkaline earth metal having a low work function and an alloy having a low work function. Al combined with high metal
Alloys such as Ca and AlLi are also known.

[0006] However, metals having a low work function are very easily oxidized. Therefore, when they are applied to EL display devices, it is necessary to sufficiently seal them. For this reason, glass sealing alone is not sufficient. In addition, the material of the light emitting layer is liable to deteriorate in characteristics due to moisture, oxygen and the like, so that sufficient protection is required.

[0007] As a protective layer for protecting an organic EL display device from intrusion of moisture or oxygen, a fluorine-based polymer thin film is known. Since the fluorine-based polymer thin film has high water repellency and almost no pinholes, it is extremely effective for protecting the cathode and the light emitting layer. Among the fluoropolymers, polytetrafluoroethylene has an extremely excellent effect of blocking moisture and oxygen, but is gasified at the time of vapor deposition or sputtering, so that it is practically impossible to form a thin film by these methods. . For this reason,
It has been proposed to use a fluorine organic compound other than polytetrafluoroethylene as a protective layer material for an organic EL display device.

For example, Japanese Unexamined Patent Publication (Kokai) No. 4-233192 discloses a single-layer or multi-layer fluorine-based polymer comprising a copolymer obtained by copolymerizing a monomer mixture containing tetrafluoroethylene and at least one comonomer. An organic electroluminescent device coated with a molecular thin film is described.

Japanese Patent Application Laid-Open No. 4-355096 discloses an organic electroluminescent device covered with a layer made of a fluorine-containing copolymer having a cyclic structure or a fluorine-based polymer thin film having a multilayer structure. I have.

JP-A-4-206386 discloses at least one polymer selected from a chlorotrifluoroethylene homopolymer, a dichlorodifluoroethylene homopolymer, and a copolymer of chlorotrifluoroethylene and dichlorodifluoroethylene. An organic electroluminescent device covered with a fluorine-based polymer thin film formed by a vapor deposition method using as a vapor source is described.

However, conventional EL devices using a fluorine-based polymer thin film as a protective layer have problems as described below.

In Japanese Patent Application Laid-Open No. 4-233192, a copolymer of tetrafluoroethylene and another comonomer is used, but specific examples of the other comonomer include specific copolymers having a cyclic structure. It is merely described that the compound of the formula (1) is a fluorine-containing compound, and that other comonomers may be used in addition to the compound having a cyclic structure. Copolymers using the specific compound having a cyclic structure are about two orders of magnitude more expensive than other fluoropolymers.

The fluorine-containing copolymer having a cyclic structure described in JP-A-4-355096 is disclosed in JP-A-4-355096.
As with the copolymer described in JP-A-233192, it is expensive, and the cost is significantly increased.

The fluorine-containing polymer substance containing chlorine described in Japanese Patent Application Laid-Open No. 4-206386 can provide a sufficient film-forming rate by a vapor deposition method or a sputtering method and is appropriate in price, but deteriorates EL characteristics. There is a problem of causing. Specifically, according to the experiments of the present inventors, when a fluorine-based polymer thin film containing chlorine is formed in contact with the cathode, the initial luminance is 10%.
And the drive voltage increases by 1 V or more. In addition, when a fluorinated polymer thin film containing chlorine is formed and then a light-emitting layer or a cathode of another EL display device is formed in the same vacuum chamber, the initial luminance of the EL display device is further reduced. The driving voltage further increases.
It is considered that this characteristic deterioration occurs because the fluorine-based polymer containing chlorine is gasified during vapor deposition or sputtering and remains in the vacuum chamber.

When the organic EL element is applied to a display device, terminals for sealing the organic functional layer and the cathode with a glass plate or the like to protect the cathode from oxygen, moisture, etc., and connecting to an external circuit. Generally, an electrode is provided outside the sealing means to connect the cathode and the terminal electrode.

In order to draw the cathode out of the sealing means, usually, a method called so-called mask film formation is used. The mask film formation is a method of forming a film in a desired region on a substrate by installing a mask having a shielding portion for limiting a film formation region on a substrate or an apparatus and performing film formation.

Using this method, the cathode and the terminal electrode can be connected in the following procedure. First, an organic functional layer is formed on a substrate using a mask having an opening corresponding to the organic functional layer formation region. At this time, at least a part of the terminal electrode is covered with the shielding portion of the mask. Thereafter, before forming the cathode, the cathode is formed by exchanging the mask with an opening corresponding to the cathode formation region, that is, a mask having an opening larger than the mask used for forming the organic functional layer. Thereby, the cathode is formed beyond the organic functional layer formation region, and the cathode and the terminal electrode can be connected.

However, the method of changing the mask after forming the organic functional layer has the following problems.

Since the replacement of the mask is usually performed manually, it is performed in the air. For example, after the formation of the organic functional layer, the mask is once returned to the atmosphere to change the mask, and then returned to the vacuum film forming apparatus to form the cathode. In this method, moisture is adsorbed on the surface of the organic functional layer exposed to the atmosphere or is taken into the layer, so that the adhesion at the interface between the cathode and the organic functional layer is deteriorated, In addition, there is a problem that the driving voltage for emitting light is increased due to poor performance, and a defect that a non-light emitting region is increased on the edge of the light emitting surface or in the light emitting surface, that is, a dark spot is generated. Another major drawback is that dust easily gets on the organic functional layer and dark spots are generated therefrom.

It is not impossible to replace the mask using a robot or the like so as not to break the vacuum, but the positioning mechanism in the vacuum becomes very large and the film forming apparatus becomes expensive. turn into. In addition, when such an alignment mechanism is not used, a wide margin needs to be provided because a positional shift occurs. For this reason, it is a portion that does not emit light when viewed from the display device user, and a so-called unnecessary region becomes large.
Further, in the case where a large number of display devices are formed on one substrate, providing a wide margin directly leads to a reduction in the number of displays, so that the manufacturing cost per display device increases.

As still another method, there is a method of installing a mask on the apparatus side. However, a large margin is required, and dust is extremely generated because the mask is used over many times of film formation. , Which was a factor in lowering the yield. In order to improve the yield, it is desirable to always use a highly clean mask, that is, to replace the mask with the substrate without installing the mask on the apparatus side.

As described above, since the cathode of the organic EL display device contains a metal having a small work function, the cathode is likely to be deteriorated or corroded by moisture, oxygen, or the like. Therefore, if the cathode itself is used as a wiring layer to connect the terminal electrode and the cathode, the cathode is likely to be deteriorated. Therefore, on the cathode,
It is preferable to provide a conductive layer made of a metal that is more stable than this, and to use a laminate of the cathode and this conductive layer or only this conductive layer as a wiring layer. The cathode is a wire bonding, heat seal connector or FPC (Flexible Pr
In some cases, it is desired to connect to an external circuit using a method such as crimping of an int circuit, but in most cases such a method requires mechanical strength and heat resistance at a connection portion of the cathode with the terminal electrode. When the cathode has a laminated structure of a cathode that is easily corroded and a stable conductive layer, the conductive layer is easily corroded when the cathode is exposed due to being damaged. It is desirable to form only from a layer.

When the conductive layer is formed on the cathode by using the above-described mask film formation, it is preferable to form each layer by the following method in order to protect the organic functional layer and the cathode from oxygen and moisture. In this method, first, a mask is provided, and an organic functional layer, a cathode, and a stable conductive layer are continuously formed. Next, the vacuum is broken and the mask is replaced with a mask having a large opening, and the vacuum is applied again to further laminate a stable conductive layer. In this method, only the uppermost conductive layer is connected to the terminal electrode, and neither the organic functional layer nor the cathode is directly exposed to the atmosphere, so that a defect is less likely to occur. However, in this method, it is necessary to return the vacuum to the atmospheric pressure once and then to the vacuum again, and it is necessary to form a stable conductive layer twice, so that the manufacturing process becomes longer and the cost increases. Become.

[0024]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances. A first object of the present invention is to
An object of the present invention is to achieve long life and low cost in an organic electroluminescence display device provided with a light emitting unit laminate having an anode, an organic functional layer including a light emitting layer, and a cathode on a substrate surface. A second object of the present invention is to achieve the first object, and when forming an organic functional layer and a cathode successively in a manufacturing process, without replacing a mask for limiting a formation area. Another object of the present invention is to provide a method for securely connecting a cathode and a terminal electrode.

[0025]

The above object is achieved by the following (1).
This is achieved by any one of the above configurations. (1) A light emitting unit laminate is provided on a substrate surface, and the light emitting unit laminate has an anode, an organic functional layer including a light emitting layer, a cathode, and a protective layer in this order. Includes a conductive inorganic material layer and an organic protective layer formed thereon, wherein the organic protective layer is at least one polymer selected from a fluorocarbon polymer containing chlorine as an evaporation source. An organic electroluminescent display device formed by a vacuum deposition method or formed by a sputtering method using the at least one polymer as a target. (2) The conductive inorganic material layer is made of Ag, Al, Au,
Cr, Mo, Pt, Ti and W, or Cu, Mo, Sc, Si and W and an alloy of Al and Ti
The organic electroluminescent display device according to the above (1), which is composed of N, ZnO, SnO ₂ or In ₂ O ₃ . (3) The organic electroluminescent display device according to (1) or (2), wherein the cathode is made of a metal having a work function of 4 eV or less. (4) A terminal electrode is provided on the surface of the substrate, wherein the conductive inorganic material layer is a wiring layer in contact with at least a part of the terminal electrode, and a gradient of an end of the conductive inorganic material layer is at least the terminal. The above (1) to 0.1 or less near the electrode
(3) The organic electroluminescent display device according to any of (3). (5) A method for manufacturing an organic electroluminescence display device according to any one of the above (1) to (4), wherein after forming an anode and a terminal electrode, a shielding portion for limiting a layer formation region and a shielding portion On a mask having an enclosed opening, the substrate is placed so that its surface side faces, then an organic functional layer and a cathode are formed, and then the step coverage is higher than the method used for forming the organic functional layer. A method for manufacturing an organic electroluminescent display device in which a conductive inorganic material layer is formed by a favorable method to bring the conductive inorganic material layer into contact with at least a part of a terminal electrode. (6) The method for manufacturing an organic electroluminescent display device according to (5), wherein the substrate is provided on the mask such that the shielding portion of the mask covers at least a part of the terminal electrode via the space. (7) The method for producing an organic electroluminescence display device according to (5) or (6), wherein the organic functional layer is formed by a vacuum evaporation method, and the conductive inorganic material layer is formed by a sputtering method.

[0026]

In the present invention, a conductive inorganic material layer is first provided on a cathode having a low work function, and an organic protective layer made of an organic fluorine compound containing chlorine is provided thereon. In the present invention, after the light-emitting layer and the cathode are covered with the conductive inorganic material layer, an organic protective layer containing chlorine is formed.Therefore, a decrease in the initial luminance which has conventionally occurred when forming an organic fluorine compound thin film containing chlorine. And an increase in driving voltage can be prevented. As described above, in the present invention, an inexpensive chlorine-containing compound can be used among the organic fluorine compounds, and the deterioration of the EL characteristics due to the compound can be suppressed. Is realized.

Further, the conductive inorganic material layer can function as a wiring layer for connecting the cathode and the terminal electrode. If only the wiring layer is provided on the cathode, a sufficient sealing effect cannot be obtained due to defects such as pinholes in the wiring layer, but an organic protective layer is formed on the conductive inorganic material layer as the wiring layer. Thereby, a good sealing effect can be obtained.

Japanese Patent Application Laid-Open No. Hei 7-212455 discloses a water-absorbing substance (polyvinyl alcohol or the like) having a water absorption of 1% or more and a moisture-proof substance having a water absorption of 0.1% or less.
Further, an organic EL device having a protective layer formed by a vapor deposition method is described. The publication describes that a fluorine-based polymer material containing chlorine can be used as the moisture-proof substance, and that the moisture-proof substance layer is preferably present outside the water-absorbing substance layer. is there. That is, in the organic EL device described in the publication, the outer portion of the protective layer is a moisture-proof material layer corresponding to the organic protective layer in the present invention. However, the inner part of the protective layer is the hygroscopic substance layer, which is different from the present invention. In the example of the publication,
5 μm thick by depositing a hygroscopic substance at a deposition rate of 2 nm / sec.
Of the material (PVA layer).
This means that it takes about 0 minutes. This film formation time is
The film formation time of the conductive inorganic material layer in the present invention is 10 times or more, which is problematic in terms of productivity. Further, unlike the conductive inorganic material layer in the present invention, the hygroscopic substance layer cannot be used as a wiring layer.

When the conductive inorganic material layer is used as the wiring layer in the present invention, it is preferable to form the conductive inorganic material layer according to the procedure described below.

First, as shown in FIG. 3, after forming the anode 2, the terminal electrode 3 and the insulating layer 4, the mask 8 is placed so that the terminal electrode 3 is covered by the shielding portion 81 of the mask 8. At this time, a space is provided between the shielding portion 81 and the terminal electrode 3 so that they do not contact each other.

Next, the organic functional layer 5 is formed by a method having relatively poor step coverage, that is, a method having a poor wraparound (for example, a vacuum deposition method). At this time, the formation of the organic functional layer 5 is restricted by the shielding portion 81, and the organic functional layer 5 is not formed in a region covered by the shielding portion 81.

Subsequently, the cathode 6 is formed without removing the mask 8, and then the conductive inorganic material layer 71 and the organic protective layer 72 are formed.
Is formed. At least the conductive inorganic material layer 71 in the protective layer 7 has a better step coverage than the film forming method used for forming the organic functional layer 5 and the cathode 6, that is, a method with good wraparound (for example, a sputtering method). To form a film. By providing a space between the substrate 1 and the mask 8, as shown in FIG. 3 (e), the conductive inorganic material layer 71 formed by a good wraparound method also enters this space, and It becomes possible to get over the layer 5 and connect to the terminal electrode 3. According to this method, the cathode 6 and the terminal electrode 3 can be electrically connected without exchanging the mask 8 after forming the organic functional layer 5.

In this method, it is preferable to keep the vacuum without removing the mask 8 until the formation of the organic protective layer 72 is completed.

According to this method, the number of mask mounting steps can be reduced by one. Also, as described above, in the past, in order to protect the cathode surface from the air, after forming the cathode, a part of the wiring layer was formed before replacing the mask, and then the mask was replaced by opening to the atmosphere. After that, the wiring layers are stacked again. However, by applying the method of the present invention, it is not necessary to divide the process of forming the wiring layers (conductive inorganic material layers) into two steps. In addition, since it is not necessary to open to the atmosphere after the organic functional layer is formed, the adhesion of dust is reduced and the yield is improved. As a result, the manufacturing cost of the organic EL display device can be significantly reduced and an organic EL display device having a long life can be realized.

In the illustrated example, since the organic functional layer 5 is completely covered with the conductive inorganic material layer 71, oxygen, water,
The organic functional layer 5 can be protected from the organic solvent used in the manufacturing process. Also, by forming the cathode 6 by a method having poor step coverage, the cathode 6 is also made of a conductive inorganic material layer 7.
1, it is possible to completely cover, so that sufficient protection is possible.

Note that Japanese Patent Application Laid-Open No. 6-52991 discloses that
Described is an organic electroluminescent element that is covered with a metal film having a work function smaller than that of the electrode from at least the side surface of the electrode provided on the back side of the organic thin film layer to the entire exposed surface of the organic thin film layer on which the electrode is formed. Have been. The organic electroluminescent device described in the publication is similar to the organic EL device according to the present invention in that the electrode is covered with a metal film made of a material different from the electrode.
It is the same as the display device. However, the publication does not disclose that the metal film is further covered with a specific organic protective layer. Further, the publication does not disclose that the metal film is directly connected to a terminal electrode. In the embodiment of the publication, a lead wire extends from the metal film. Further, in the example of the publication, both the electrode and the metal film are formed by a vapor deposition method, which is different from the method of the present invention.

[0037]

FIG. 1 shows an example of the structure of an organic EL display device according to the present invention. The EL display device shown in FIG. 1 has an anode 2, an insulating layer 4, an organic functional layer 5 including a light emitting layer, and a cathode 6 in this order on a substrate 1, and further comprises a conductive inorganic material on the cathode 6. The protective layer 7 includes a layer 71 and an organic protective layer 72. The terminal electrode 3 is provided on the substrate 1. The conductive inorganic material layer 71 in the illustrated example functions as a wiring layer that connects the cathode 6 and the terminal electrode 3. The insulating layer 4 is formed in a region on the anode 2 to be a non-light emitting portion.
A region of the anode 2 extending to the right side of the insulating layer 4 is a terminal portion 21 for connecting the anode 2 to an external circuit.
The insulating layer 4 is provided to prevent the anode 2 from contacting the cathode 6 to be formed later. The contact between the two electrodes means that the cathode and the anode of the organic EL element to be separated are electrically short-circuited. Therefore, it is necessary to provide the insulating layer 4.

Hereinafter, each part of the organic EL display device will be described.

Substrate In the organic EL display device of the present invention, the substrate 1 of the organic functional layer 5
Since the protective layer 7 is provided on the side opposite to the above, light emitted by the organic functional layer 5 is extracted through the substrate 1. Therefore, a transparent or translucent material such as glass, quartz, or resin is used for the substrate. Inexpensive soda glass can be used for the substrate. In this case, it is preferable to coat the entire surface of the substrate with silica. The silica coat has a role of protecting soda glass that is susceptible to acid and alkali, and also has an effect of improving the flatness of the substrate.

The emission color may be controlled by disposing a color filter film, a color conversion film containing a fluorescent substance, or a dielectric reflection film on the substrate.

The material and thickness of anode anode, the transmittance of the emitted light is preferably selected to be 80% or more. Specifically, it is preferable to use, for example, tin-doped indium oxide (ITO), zinc-doped indium oxide (IZO), SnO ₂ , or polypyrrole doped with a dopant for the anode. The thickness of the anode is preferably about 10 to 500 nm.

Organic Function Layer Including Light Emitting Layer The light emitting layer has a function of injecting holes (holes) and electrons, a function of transporting them, and a function of generating excitons by recombination of holes and electrons. It is preferable to use a relatively electronically neutral compound for the light emitting layer.

The organic functional layer preferably contains a hole injection / transport layer in addition to the light emitting layer. The hole injection transport layer is
It has a function of facilitating injection of holes from the anode, a function of transporting holes, and a function of hindering electrons. In addition, if necessary, for example, when the electron injecting and transporting function of the compound used in the light emitting layer is not so high, an electron injecting and transporting layer may be provided between the light emitting layer and the cathode.
The electron injection transport layer has a function of facilitating injection of electrons from the cathode, a function of transporting electrons, and a function of preventing holes. The hole injecting and transporting layer and the electron injecting and transporting layer increase holes and electrons injected into the light emitting layer and improve luminous efficiency.

The hole injection / transport layer is provided between the anode and the light emitting layer, and the electron injection / transport layer is provided between the cathode and the light emitting layer.

The hole injecting and transporting layer and the electron injecting and transporting layer may be provided separately as a layer having an injection function and a layer having a transport function.

The thickness of the light emitting layer, the thickness of the hole injection transport layer, and the thickness of the electron injection transport layer are not particularly limited. These thicknesses vary depending on the forming method, but are usually 5 to 1
It is about 00 nm. Carrier mobility and carrier density of each layer (determined by ionization potential and electron affinity)
By controlling the thickness of each layer in consideration of, it is possible to freely design the recombination region and the light emitting region, design of the emission color, control of the emission luminance and emission spectrum by the interference effect of both electrodes, The spatial distribution of light emission can be controlled.

The light emitting layer contains a fluorescent substance which is a compound having a light emitting function. For example, fluorescent substances include
Metal complex dyes such as tris (8-quinolinolato) aluminum as disclosed in JP-A-63-264692 can be used. In addition to or in place of this, quinacridone, coumarin, rubrene, styryl dyes, other tetraphenylbutadiene, anthracene, perylene, coronene, 12-phthaloperinone derivatives, and the like can also be used. The light emitting layer may also serve as the electron injection / transport layer. In such a case, it is preferable to use tris (8-quinolinolato) aluminum or the like.

The electron injecting and transporting layer is formed of an organic metal complex such as tris (8-quinolinolato) aluminum, an oxadiazole derivative, a perylene derivative, a pyridine derivative, a pyrimidine derivative, a quinoline derivative, a quinoxaline derivative, a diphenylquinone derivative, and a nitro-substituted fluorene. Derivatives and the like can be used. As described above, the electron injection / transport layer may also serve as the light emitting layer. In such a case, it is preferable to use tris (8-quinolinolato) aluminum or the like.

When the electron injecting and transporting layer is provided separately for the electron injecting layer and the electron transporting layer, a preferable combination can be selected from the compounds for the electron injecting and transporting layer and used for each layer. At this time, it is preferable to stack the layers of the compound having the highest electron affinity from the cathode side. Such a stacking order is the same when two or more electron injection / transport layers are provided.

The hole injecting and transporting layer is described in, for example,
-2956995, JP-A-2-191694, JP-A-3-792, JP-A-5-234681
JP, JP-A-5-239455, JP-A-5-5-2
JP-A-99174, JP-A-7-126225, JP-A-7-126226, JP-A-8-100172
Patents, EP 0650955 A1, etc., for example, tetraarylbendicine compounds (tetraaryldiamine to tetraphenyldiamine: TPD), aromatic tertiary amines, hydrazone derivatives, carbazole derivatives, triazole derivatives, imidazole derivatives And an oxadiazole derivative having an amino group, polythiophene, and the like. These compounds may be used in combination of two or more. When they are used in combination, they may be stacked as separate layers or mixed.

When the hole injecting and transporting layer is provided separately for the hole injecting and transporting layers, a preferable combination can be selected from the compounds for the hole injecting and transporting layer. At this time, it is preferable to stack the layers of the compound having the smaller ionization potential in order from the anode. It is preferable to use a compound capable of forming a uniform thin film for the layer provided on the anode surface. Such a stacking order is the same when two or more hole injection / transport layers are provided. With such a stacking order, the driving voltage is reduced, and the occurrence of current leakage and the occurrence and growth of dark spots can be prevented. Further, when formed by a vapor deposition method, even a thin film having a thickness of about 1 to 10 nm can be made uniform and pinhole-free. Therefore, even when a compound having a low ionization potential and having absorption in the visible region is used for the hole injection layer, it is possible to prevent a change in the color tone of the emission color and a decrease in efficiency due to reabsorption.

The layers constituting the organic functional layer may be formed by a vapor deposition method or a sputtering method, but is preferably formed by a vapor deposition method as described above.

Cathode The cathode is preferably made of a metal (including alloys and intermetallic compounds) having a work function of 4 eV or less. When the work function exceeds 4 eV, the efficiency of electron injection decreases, and the luminous efficiency decreases.

As a material used for forming the cathode, for example,
Alkali metals such as Li, Na and K; Mg, Ca, Sr,
Alkaline earth metals such as Ba; rare earth metals such as La and Ce; Al, In, Ag, Sn, Zn, Zr and the like; and at least one of them is selected so as to obtain a cathode having a desired work function. Just choose. As an alloy having a work function of 4 eV or less, for example, Ag · Mg (Ag: 1 to 20)
Atomic%), Al.Li (Li: 0.5 to 10 atomic%),
In.Mg (Mg: 50-80 atomic%), Al.Ca
(Ca: 5 to 20 atomic%).

For forming the cathode, a sputtering method may be used, but in the present invention, a vapor deposition method is preferably used.

The thickness of the cathode may be appropriately determined so that electron injection can be sufficiently performed, but is preferably 50 nm or more, more preferably 100 nm or more. Although there is no particular upper limit on the thickness of the cathode, it is generally not necessary for the cathode to have a thickness exceeding 500 nm.

The constituent material of the protective inorganic conductive material layer is not particularly limited, and a conductive metal (including an alloy and an intermetallic compound) and a conductive ceramic can obtain the conductivity required for the wiring layer as described above. A material that can sufficiently protect the cathode and the organic functional layer when forming the organic protective layer may be appropriately selected. Such conductive inorganic materials include Ag, A
l, Au, Cr, Mo, Pt, an alloy of at least one of Ti, W and Cu, Mo, Sc, Si and W with Al, or TiN, ZnO, SnO ₂ or In ₂ O ₃ is preferable. .

The thickness of the conductive inorganic material layer is preferably 3
0 nm to 1 μm, more preferably 50 nm to 0.5 μm
It is. If the conductive inorganic material layer is too thin, the step coverage of the conductive inorganic material layer will be low, and the connection with the terminal electrode will not be sufficient. On the other hand, if the conductive inorganic material layer is too thick, the stress of the conductive inorganic material layer increases, and the growth rate of dark spots increases.

The organic protective layer is formed by a vacuum evaporation method using at least one polymer selected from a fluorocarbon polymer containing chlorine as an evaporation source, or the at least one polymer. And a fluorine-based organic polymer thin film containing chlorine. As the fluorocarbon polymer serving as an evaporation source or a target, a homopolymer of a fluorocarbon compound containing chlorine and a copolymer thereof are preferable. As the homopolymer and the copolymer, chlorotrifluoroethylene homopolymer, dichlorodifluoroethylene homopolymer, a copolymer of chlorotrifluoroethylene and dichlorodifluoroethylene are preferable, and particularly, chlorotrifluoroethylene homopolymer is preferable. Coalescence is preferred. In the present invention, in addition to these homopolymers and copolymers, copolymers of tetrafluoroethylene and chlorotrifluoroethylene or dichlorodifluoroethylene can also be used. The molecular weight of each polymer is preferably 400
The number is more preferably 1,000 to 600,000, and still more preferably 10,000 to 500,000. When a copolymer is used, the copolymerization ratio is not particularly limited. For example, in a copolymer of chlorotrifluoroethylene and dichlorodifluoroethylene, chlorotrifluoroethylene:
It is preferable that dichlorodifluoroethylene = 2: 1 to 10: 1.

The organic protective layer formed by vapor deposition or sputtering is composed of substantially the same polymer as the vapor deposition source or target.

The thickness of the organic protective layer is preferably from 10 nm to
It is 100 μm, more preferably 50 nm to 10 μm. If the organic protective layer is too thin, the sealing effect becomes insufficient,
If the thickness is too large, the stress increases, and the growth rate of dark spots increases.

The conductive inorganic material layer may be composed of a plurality of layers having different targets and evaporation sources, and the same applies to the organic protective layer.

The protective layer includes a non-fluorinated organic material layer and a non-conductive inorganic material layer between the conductive inorganic material layer and the organic protective layer in addition to the conductive inorganic material layer and the organic protective layer. May be.

The conductive inorganic material layer and the organic protective layer are formed by a vapor deposition method or a sputtering method. When a sputtering method is used, a thin film having good step coverage can be formed. For this reason, it becomes easy to completely cover the cathode and the organic functional layer, and it is easy to use the conductive inorganic material layer as the wiring layer.

When the conductive inorganic material layer is made of TiN, it is preferable to use a reactive sputtering method using Ti as a target. At this time, the reactive gas includes
N ₂ or the like may be used.

[0066] the material of the terminal electrode terminal electrode is not particularly limited, for example ITO,
TiN, Al or the like may be used. However, after forming the cathode and the organic protective layer, when sealing and sealing the sealing plate and the like with an adhesive, when using an ultraviolet-curing adhesive as the adhesive, and when irradiating ultraviolet rays from the substrate side Preferably, the terminal electrode is made of a material having a high light transmittance.
As the electrode material in this case, various materials described in the description of the anode are preferable. Usually, a terminal electrode is formed simultaneously with the anode by patterning at the time of forming the anode.

Insulating layer A film formed by sputtering or vacuum deposition of an inorganic material such as silicon oxide such as SiO ₂ or silicon nitride, a silicon oxide layer formed by SOG (spin-on-glass), photoresist, polyimide, Any material having an insulating property such as a coating film of a resin material such as an acrylic resin may be used. However, since an anode made of ITO or the like exists below the insulating layer, it is preferable to use a material that can be patterned so as not to damage the anode when patterning the insulating layer.

The thickness of the insulating layer is not particularly limited, and may be appropriately determined according to the material so as to obtain necessary insulating properties. However, when an inorganic material is used, it is preferable that the thickness is thinner in terms of manufacturing cost. .

After the formation of the sealing organic protective layer, it is preferable that the sealing plate is bonded to seal the region except at least a part of the terminal electrode 3 between the substrate 1 and the sealing plate. Thereby, invasion of moisture can be prevented, and the mechanical strength also increases. For the adhesion of the sealing plate, for example, a photocurable adhesive, an epoxy-based adhesive, a silicone-based adhesive, a crosslinked ethylene-vinyl acetate copolymer adhesive sheet, or the like may be used. Glass, ceramics, metal, resin, or the like may be used for the sealing plate.

The organic EL display device of the present invention is not limited to the isolated type described above, but can be applied to a multi-pixel structure such as a simple matrix type or a thin film transistor (TFT) type.

The organic EL display device of the present invention is usually driven by a direct current, but may be driven by an alternating current or a pulse. The applied voltage is usually about 5 to 20V.

The anode, the organic functional layer, and the cathode can be patterned by using a mask at the time of formation, or by processing the shape by etching or the like after the formation, whereby a desired light emission pattern can be obtained.

Details of Manufacturing Method Referring to FIGS. 2 and 3, the manufacturing method of the present invention will be schematically described. FIGS. 2A to 2F are plan views of the organic EL display device as viewed from the surface side of the substrate 1 in a manufacturing process.
FIGS. 3A to 3F are cross-sectional views taken along lines AA to FF shown in FIG. 2, respectively. However, only the end face of the section is shown in this sectional view. The same applies to the cross-sectional views described below.

First, as shown in FIG.
The anode 2 and the terminal electrode 3 are formed thereon. Here, the terminal electrode 3 is formed simultaneously with the anode 2 by masking when forming the anode 2 or etching after the formation of the anode 2. However, a terminal electrode 3 may be formed by forming a conductive layer different from the anode 2. Good.

Next, as shown in FIG.
The insulating layer 4 is formed in an upper region to be a non-light emitting portion.

Then, the substrate 1 is mounted on the mask 8 as shown in FIG. As shown, the mask 8
Is composed of a shielding portion 81 and a base portion 82 having different sizes of openings. The shielding portion 81 having a small opening is present on the side (lower side in the illustrated example) from which the material to be deposited comes, and serves to shield the deposition material. On the other hand, the base 82 having a small opening exists on the substrate 1 side, and keeps the distance between the shielding portion 81 and the substrate 1 constant. The width of the wraparound of the film forming material is determined by the “distance between the shielding portion 81 and the substrate 1” and the “film forming method”. In order to form the organic functional layer 5 substantially in accordance with the opening pattern of the mask and to sufficiently ensure the wraparound of the conductive inorganic material layer 62, the back surface of the shielding portion 81 (the surface on the substrate 1 side) and the surface of the substrate 1 Is preferably 0.1 to 5 mm, more preferably 0.3 to 1.5 mm. However, the sum of the thickness of the substrate 1 and the thickness of the mask 8 (substrate 1
The distance from the back surface to the surface of the mask 8) is preferably 5 mm or less, more preferably 3 mm or less. Note that, as the mask 8, a plastic mask made of a resin or a metal mask made of a metal such as SUS, Ti, or Al is usually used.

When a general vacuum evaporation method is used, the evaporation material flying to the substrate 1 is shielded by the shielding portion 81,
A vapor deposition film having a pattern approximately the same size as the opening of the shielding portion 81 is formed. That is, the general vacuum vapor deposition method has poor step coverage, and there is almost no wraparound of the vapor deposition material.
Therefore, if the organic functional layer is formed by a vacuum deposition method, the organic functional layer 5 having a pattern corresponding to the opening of the shielding portion 81 of the mask 8 is formed.

After forming the organic functional layer 5, as shown in FIGS. 3D and 3E, the cathode 6 is formed without replacing the mask 8 and breaking the vacuum, The conductive inorganic material layer 71 is formed. The cathode 6 is preferably formed by a vacuum deposition method having poor step coverage so as to be completely covered by the conductive inorganic material layer 71 formed on the surface thereof. The cathode 6 formed by such a method is
As shown in FIG. 3D, the pattern becomes almost the same as that of the organic functional layer 5. After the formation of the cathode 6, the conductive inorganic material layer 71 is formed by a method having better wraparound than the vacuum deposition method, specifically, a method having good step coverage. The conductive inorganic material layer 71 formed by such a method goes around the base 82 side of the mask 8 beyond the formation pattern of the organic functional layer 5 and the cathode 6 as shown in FIG. It will be connected to the electrode 3. Conductive inorganic material layer 7
As one constituent material, a metal more stable than the constituent material of the cathode 6 is used, so that the connection between the cathode 6 and the terminal electrode 3 is made by a stable metal. Note that each of the cathode 6 and the conductive inorganic material layer 71 may be composed of a plurality of layers having different compositions.

In the illustrated example, since the entire area of the shielding portion 81 of the mask 8 is separated from the substrate 1, the organic functional layer 5 and the cathode 6 are completely covered by the conductive inorganic material layer 71. Therefore, a good protection effect can be obtained. However, in order to connect the conductive inorganic material layer 71 to the terminal electrode 3, it is not necessary to provide a space between the shielding layer 81 and the substrate 1 in the entire area near the opening of the shielding section 81, and at least one of the shielding section 81 and the terminal electrode 3 is required. It is only necessary to provide a space between the parts.

The organic protective layer 72 is also formed without removing the mask 8. The method for forming the organic protective layer 72 is not particularly limited, and may be formed by any method such as a sputtering method and a vapor deposition method. However, in order to enhance the protection effect, a method with good step coverage is preferably used. The conductive inorganic material layer 71 is completely covered with the conductive inorganic material layer 71 as shown in FIG.

After the formation of the organic protective layer 72, the mask 8 is removed to obtain an organic EL display having the structure shown in FIG.

In the above, the configuration in which only the conductive inorganic material layer 71 is used as the wiring layer has been described. However, the cathode 6 may also be formed by a method with good wraparound and may be a part of the wiring layer. Also in this case, since the surface of the cathode 6 is covered with the conductive inorganic material layer 71, the effect of not requiring replacement of the mask 8 as well as the effect of protecting the organic functional layer 5 and the cathode 6 are obtained as in the above example. Can be However, as described above, when the connection portion with the terminal electrode is a laminate of the cathode and the conductive inorganic material layer, the cathode is exposed when the conductive inorganic material layer is damaged, and is easily corroded. For this reason, it is preferable that the connection portion be formed only of the conductive inorganic material layer.

In FIGS. 2 and 3, the mask 8 in which two members having different opening sizes are bonded is described as an example. However, the present invention is not limited to the mask having this configuration, and the opening is located on the opposite side of the substrate side from the substrate side. Any structure may be used as long as the mask is larger. Examples of such a mask include a mask having a step or an inclination on the inner peripheral side surface of a shielding portion forming an opening. Specifically, in addition to the mask 8 shown in FIGS. 2 and 3, for example, a mask 8 as shown in FIG. 4 may be used. The mask 8 shown in FIG. 4A has the same outer shape as the mask 8 shown in FIG. 3, but is provided with a shielding portion 81 and a base portion 82 by shaping one plate-like body. is there. FIG. 4B is a diagram in which the inner peripheral side surface of the opening of one mask 8 is processed into a tapered shape so that the opening on the substrate 1 side is enlarged.

The gradient of the end of the conductive inorganic material layer formed by the above-described method having good step coverage is usually as extremely small as 0.1 or less. FIG.
As shown in (a), the gradient at the end of the conductive inorganic material layer 71 is represented by the ratio v / h of the change amount v of the vertical position to the change amount h of the horizontal position. On the other hand, when a method having poor step coverage similar to the method used for forming the organic functional layer is used for forming the conductive inorganic material layer, for example, when a normal vapor deposition method is used, v / h is usually 0. .5 or more. Therefore, by examining the gradient of the end portion of the conductive inorganic material layer and the position where the gradient starts, it is possible to determine whether or not the mask is exchanged between the organic functional layer forming step and the conductive inorganic material layer forming step. .

In the sputtering method described as a method having good step coverage in the above description, if the pressure of the sputtering gas is high, the frequency of the particles scattered from the target colliding with the sputtering gas and being scattered becomes high. Coverability is improved. The particles scattered from the target collide with the sputter gas atoms at least once on average before reaching the substrate, in other words, the mean free path of the scattered particles is shorter than the distance between the target and the substrate. It is preferable to select a sputtering gas pressure for the first time. On the other hand, if the pressure of the sputtering gas is too high, the particles scattered from the target will be scattered too much, and the voltage applied to the target will decrease, so that the deposition rate will decrease. Therefore, the pressure of the sputtering gas may be appropriately determined in consideration of the step coverage and the film forming rate, but is preferably 2 × 10 ⁻⁴ to 2 × 10 ⁻² Torr, more preferably 1 × 10 ⁻² Torr.
× 10 ^-3 to 1 × 10 ^-2 Torr. Note that Ar is usually used as a sputtering gas. Therefore, the fact that the sputtering method was used for film formation can be confirmed by measuring the amount of Ar in the layer. The Ar content in the layer formed by the sputtering method is usually about 0.01 to 15 atomic%. On the other hand, when the vapor deposition method is used, Ar is not substantially contained in the layer.

Examples of a method having good step coverage include a plasma CVD method and a photo CVD method in addition to the sputtering method, and these methods may be used in the present invention. Also,
In a vacuum vapor deposition method, when an inert gas such as Ar is introduced into a vapor deposition atmosphere, step coverage can be improved, so that it can be used for forming a conductive inorganic material layer. However, it is most preferable to use the sputtering method because the productivity and the uniformity are highest.

As described above, even in the vacuum deposition method, if the atmospheric pressure during the vapor deposition is high, the step coverage becomes good. Therefore, if it is necessary to deteriorate the step coverage, the pressure at the time of vapor deposition is increased. It is preferably at most 1 × 10 ⁻⁵ Torr, more preferably at most 1 × 10 ⁻⁶ Torr.

It is preferable that the side end surface of the anode 2 has a gradient not perpendicular to the substrate 1. This is to prevent a thin film formed later by a vapor deposition method or the like on the side end face of the anode 2 from being deteriorated in coverage, thereby improving yield and life. In FIG. 5B, an angle θ (hereinafter referred to as a taper angle) between the side end surface of the anode 2 and the surface of the substrate 1 is 6
It is preferable that it is 0 ° or less. It is possible to form a step having a small taper angle by any of wet etching and dry etching. For example, in wet etching, etching progresses isotropically. Therefore, if the over-etching time is not too long, the taper angle can be naturally set to about 60 ° or less, and can easily be set to 45 ° or less. Also, in the dry etching method, if the etching conditions such as dry etching gas, RF input power, and gas pressure are selected so as to transfer the taper angle of the resist, that is, a method utilizing receding due to dry etching of the resist, 20 to 30 ° Can be easily obtained. At this time, as a dry etching gas,
Hydrogen halide gas such as hydrogen chloride and hydrogen iodide, bromine gas, and methanol are used.

[0089]

EXAMPLES Example 1 EL display device samples shown in Table 1 were produced by the following procedure.

Sample No. 1 (Example of the Present Invention ) A transparent anode made of ITO was formed on a glass substrate by RF sputtering. Sputter rate is 10nm / mi
n, and the thickness of the anode was 200 nm. After patterning the anode, it was subjected to ultrasonic cleaning using a neutral detergent, acetone and ethanol, pulled out from boiling ethanol and dried, and the surface of the anode was washed with UV / O ₃ .

Next, after fixing the substrate on which the anode was formed to a substrate holder in a vacuum chamber of a vacuum evaporation apparatus, the pressure in the vacuum chamber was reduced to 1 × 10 ⁻⁶ Torr or less. While maintaining this reduced pressure state, using a deposition source of 4,4 ', 4 "-tris (3-methylphenylphenylamino) phenylamine (MTDATA), a deposition was performed to a thickness of 40 nm at a deposition rate of 0.2 nm / sec. And a hole injection layer on which N, N, N ', N'-tetrakis (3-biphenyl) -4,4'-diamino-1,1'-biphenyl was kept under reduced pressure. (TPD) was deposited at a deposition rate of 0.2 nm / sec to a thickness of 35 nm to form a hole transport layer.

Subsequently, the tris (8-
Using (quinolinolato) aluminum (hereinafter referred to as Alq ₃ ) as an evaporation source, it was evaporated to a thickness of 50 nm at an evaporation rate of 0.2 nm / sec to form an electron injection transport / emission layer.

Next, while maintaining the reduced pressure state, Mg.Ag
Alloy (weight ratio 10: 1) is deposited at a deposition rate of 0.2 nm / sec.
Evaporated to a thickness of 0 nm. The pressure during deposition is 1 × 10 ^-6 To
rr. The work function of the Mg-Ag alloy is 3.8 eV
Met.

Next, a conductive inorganic material layer was formed by sputtering using Al as a target. The pressure of the sputtering gas (Ar) was 4 × 10 ⁻³ Torr. The sputtering rate was 1.0 nm / s, and the thickness of the conductive inorganic material layer was 200 n.
m.

Next, an organic protective layer was formed on the conductive inorganic material layer by an evaporation method using a chlorotrifluoroethylene homopolymer as an evaporation source. The pressure during deposition is 1 × 10
^-4 Torr. The deposition rate was 0.5 nm / sec, and the thickness of the organic protective layer was 500 nm.

Sample No. 2 (Example of the present invention) Sample No. 2 except that the conductive inorganic material layer was made of TiN
It was produced in the same manner as in No. 1. TiN was formed by a reactive sputtering method.

Sample No. 3 (Comparative Example) Sample No. 1 except that no conductive inorganic material layer was provided.
It was produced in the same manner as described above.

Sample No. 4 (Comparative Example) Sample No. 4 was prepared in the same manner as Sample No. 1 except that no organic protective layer was provided.

In an atmosphere of 22 ° C. and 50% RH,
A DC voltage was applied to each of the above samples to continuously drive them at a constant current density of 10 mA / cm ² , and the initial luminance and the driving voltage were measured. The emission light of each sample was green (emission maximum wavelength λmax = 520 nm).

The life of each sample was evaluated according to the following criteria. : No dark spot having a diameter of 100 μm or more was generated after 1000 hours of continuous driving. ×: A dark spot having a diameter of 100 μm or more was generated after 1000 hours of continuous driving. XX: A dark spot having a diameter of 100 μm or more was generated after 100 hours of continuous driving.

The results are shown in Table 1.

[0102]

[Table 1]

From the results shown in Table 1, the effect of the present invention is clear. That is, in the comparative example sample in which the conductive inorganic material layer was not provided, a decrease in initial luminance and an increase in driving voltage were observed with respect to the sample of the present invention, and a dark spot was generated in a very short time and grew. ing. Further, in the comparative example sample in which the organic protective layer was not provided, dark spots were generated in a short time and grown, compared to the sample of the present invention, and a sufficient sealing effect was obtained with the conductive inorganic material layer alone. It turns out that it cannot be obtained. The luminance half-life of the comparative sample was shorter than that of the inventive sample.

Embodiment 2 As shown in FIG. 6A, the pixel size is 0.4 mm × 0.6.
An example in which a dot matrix display of a type having a character display area of 5 dots × 8 dots composed of mm dots and having 2 rows × 16 columns is shown. FIG. 6A shows an enlarged view of the character display area, and the terminal 2 of the anode 2.
1 and an enlarged view of the terminal electrode 3 connected to the conductive inorganic material layer 71 are also shown. FIGS. 6B and 6C show the positions of the openings of the mask 8 in the manufacturing process, where FIG. 6B is a plan view and FIG.
FIG. 4 is a partially omitted cross-sectional view taken along line -C. However, (c)
Indicates a state before the organic functional layer is formed.

FIGS. 7 and 8 are explanatory views of the manufacturing process, and for the sake of simplicity, a part of the region A of FIG. 6 is enlarged. FIG. 7 is a plan view seen from the surface side of the substrate 1.
(A-1) to (d-1) of FIG.
FIG. 7A is a sectional view taken along lines AA to DD in FIG. 7 and lines AA, B2-B2, and B3-B3 in FIG. 2) to (d-2) and (a-2), (b-2), and (b-3) in FIG.

As the substrate 1, an inexpensive soda glass coated with silica over its entire surface was used. This is for protecting soda glass which is susceptible to acid and alkali, and for improving the flatness of the glass surface.

Next, in order to form the anode 2 and the terminal electrode 3, a transparent conductive layer having a thickness of 1000 A made of ITO was formed by a sputtering method. After forming a resist pattern by photolithography on this transparent conductive layer,
Unnecessary portions were removed by etching, and then the resist was peeled off to form the anode 2 and the terminal electrode 3 as shown in (a-1) and (a-2) of FIG. The taper angle of the side end surfaces of the anode 2 and the terminal electrode 3 (the angle θ shown in FIG. 5B)
Was 45 °. The side end face having this taper angle is H
It was formed by etching for 2 minutes with an etching solution composed of a mixture of Cl, HNO ₃ and water.

Next, (b-1) and (b-2) of FIG.
As shown in FIG. 3, an insulating layer 4 covering the anode 2 and the terminal electrode 3
Was formed on the entire surface of the substrate 1. Polyimide was used for the insulating layer 4. Polyimide was selected from non-photosensitive materials, diluted with NMP (N-methyl pyrrolidone) to a concentration of about 5%, applied by spin coating, and baked at 150 ° C. for 30 minutes and further at 300 ° C. for 1 hour.

Next, in order to fabricate a structure for separating pixels, as shown in FIGS. 7C-1 and 7C-2, an Al layer 91 having a thickness of 1 μm and a thickness of 0.1 μm are formed. 2 μm
Was continuously formed.

Subsequently, a positive resist was applied, exposed and developed to form a desired photo pattern.
Further, the Cr layer 92 was etched with a cerium ammonium nitrate solution, and the Al layer 91 was etched with a mixed solution of phosphoric acid, nitric acid, and acetic acid. At this time, when the aluminum layer 91 was immersed in the etching solution for such a time period as to be sufficiently over-etched, the initial photo pattern was approximately 2
The μmAl pattern became small, and a hat-shaped structure (overhang) 9 as shown in (d-1) and (d-2) of FIG. 7 was obtained.

Further, by photolithography,
After forming a pattern having an opening for exposing the anode 2 and the terminal electrode 3 serving as the actual light emitting portion, etching the insulating layer 4 with oxygen plasma, the resist is peeled off, and the resist is removed. The structure shown in (a-2) was adopted.

Next, as shown in (b-1), (b-2) and (b-3) of FIG. 8, a mask 8 was set on the substrate 1. This mask 8 is formed of a metal mask (SU) having different openings.
(Made of S304), and the thickness of the base 82 existing on the substrate 1 side is 1 mm, and the thickness of the shielding portion 81 is 0.1 mm.
1 mm. The overhang amount of the shielding portion 81 with respect to the base portion 82 at the mask opening is 2 mm.

Next, as shown in FIG. 8C, the organic functional layer 5, the cathode 6, and the protective layer 7 (the conductive inorganic material layer 7) are formed.
1 and the organic protective layer 72) were continuously formed. The vacuum was not broken and the mask 8 was not replaced until the formation of the organic protective layer 72 was completed.

The organic functional layer 5 was composed of a hole injection layer, a hole transport layer, and an electron injection transport / light emitting layer. Each of these layers was formed in the same manner as in Example 1.

The cathode 6 has a thickness of 2000 A,
It was formed by vapor deposition of an alloy (weight ratio 10: 1). The pressure during vapor deposition was 1 × 10 ⁻⁶ Torr.

The conductive inorganic material layer 71 has a thickness of 0.3 μm and is formed by a sputtering method using Al as a target. The pressure of the sputtering gas (Ar) was 4 × 10 ⁻³ Torr. The gradient v / h at the end of the conductive inorganic material layer 71 shown in FIG. 5A was 0.05. The amount of Ar in the conductive inorganic material layer 71 was about 3 atomic%. In addition, A in the cathode 6
The r amount was below the detection limit.

The organic protective layer 72 was made of the sample N of Example 1.
o.

Lastly, after taking out from the film forming apparatus, the mask 8 is removed, and sealing for shielding the whole from outside air is performed.
The terminal electrode 3 was connected to an external circuit to complete a dot matrix display.

In this display, similarly to the sample of the present invention of Example 1, no decrease in the initial luminance and no increase in the driving voltage were observed. Further, the dark spot and the luminance half life were also the same as those of the sample of the present invention of Example 1.

Embodiment 3 The size of one pixel is 330 μm × 110 μm and the number of pixels is 3
An example of manufacturing a color display of 20 × 240 × RGB dots is shown. Basically, there is no significant difference from the second embodiment except that the color is changed and the definition is further improved.

First, a pigment dispersion type color filter, which is the most common method for colorizing a liquid crystal display, was formed. The filter liquid of each color was applied so as to have a filter thickness of about 1.5 to 2.5 μm, and was patterned. In the process of forming a color filter, taking red as an example,
The procedure was as follows. 100 color filter solution for red
Spin coating was performed at 0 rpm for 5 seconds and prebaked at 100 ° C. for 3 minutes. Align the photomask with the exposure machine, and set 20mW
Irradiate with UV light for 30 seconds, and then TM
Developed with AH aqueous solution. The development time was about 1 minute.
Next, the mixture was cured at 220 ° C. for 1 hour so as not to dissolve in a color filter liquid of another color to be applied thereafter, thereby completing a red color filter pattern. Other colors (green,
The blue) color filter was formed by sequentially performing substantially the same steps, although slightly different from the above-described red color filter forming conditions due to different materials (pigments). Here, since the manufacture is relatively easy, an example using only a color filter has been described, but green and red are output by performing color conversion using a fluorescence conversion filter, so as to emit light with higher luminance. Is also good. Further, it is also possible to stack a color filter and a fluorescence conversion filter so as to achieve both the prevention of luminance reduction and the improvement of color purity.

Next, as shown in FIG. 9A, an overcoat material is applied to the entire surface of the substrate 1 from above the color filter patterns (R, G, B in the figure).
Cured at 1 ° C. for 1 hour to form an overcoat layer 11
To improve the flatness of the surface on which the transparent conductive layer is formed.

Next, the surface of the overcoat layer 11 was coated with ITO.
Was formed by sputtering, a resist pattern was formed by photolithography, etching was performed, and finally the resist was peeled off. Thus, a column line made of ITO was formed as shown in FIG. At this time, the pattern of the terminal electrode 3 is also formed at the same time. The taper angle (the angle θ shown in FIG. 5B) of the side end surfaces of the anode 2 and the terminal electrode 3 was 45 °. The side end face having this taper angle was formed by etching for 2 minutes with an etching solution comprising a mixed solution of HCl, HNO ₃ and water.

Next, an insulating layer 4 having a thickness of 0.2 μm is formed on the anode 2 by sputtering using SiO ₂ as a target, and an Al layer 9 having a thickness of 1 μm is formed by sputtering.
1 and a Cr layer 92 having a thickness of 0.2 μm were formed.
The structure shown in FIG.

Next, the Cr layer 92 and the A
The l layer 91 was etched. Subsequently, after forming a pattern for exposing the surface of the anode 2 by photolithography, the insulating layer 4 was etched to expose the light emitting region and the terminal electrode 3, and finally the resist was removed. Note that an etching solution in which hydrofluoric acid and an aqueous solution of ammonium fluoride were mixed at a ratio of 1:20 was used for etching the insulating layer 4.

Next, as shown in FIG.
After the mask 8 similar to the mask 8 used in the above is installed on the substrate 1, the mask 8 is introduced into the film forming apparatus, and the organic functional layer 5, the cathode 6, and the protective layer 7 (the conductive inorganic material layer 71 and the organic protective layer 72 )
Are formed continuously to obtain a structure shown in FIG. The vacuum was not broken and the mask 8 was not replaced until the formation of the organic protective layer 72 was completed.

The organic functional layer 5 includes a hole injecting layer having a thickness of 100 A, a hole transporting layer serving as a yellow light emitting layer having a thickness of 500 A, a blue light emitting layer having a thickness of 500 A, and an electron transporting layer having a thickness of 100 A. And the material was selected so as to emit white light. The hole injection layer was formed by evaporating poly (thiophene-2,5-diyl). The hole transporting layer and the yellow light emitting layer are T
It was formed by co-evaporation of PD doped with rubrene at a ratio of 1% by weight. The concentration of rubrene is 0.1
The concentration is preferably about 10 to 10% by weight, and light is emitted with high efficiency at this concentration. The density may be determined from the color balance of the emission color,
It depends on the light intensity and the wavelength spectrum of the blue light emitting layer to be formed thereafter. The blue light emitting layer is composed of 4,4′-bis [(1,
2,2-triphenyl) ethenyl] biphenyl. Electron-transporting layer was formed by depositing Alq _3.

The cathode 6 has a thickness of 2000 A, and is composed of Mg / Ag
It was formed by vapor deposition of an alloy (weight ratio 10: 1). The pressure during vapor deposition was 1 × 10 ⁻⁶ Torr.

The conductive inorganic material layer 71 was formed to a thickness of 0.3 μm by sputtering using Al as a target. The pressure of the sputtering gas was 4 × 10 ⁻³ Torr. FIG.
(A) The gradient v / h of the end of the conductive inorganic material layer 71 shown in FIG.
Was 0.05. Ar in the conductive inorganic material layer 71
The amount was about 3 atomic%. Note that the amount of Ar in the cathode 6 was below the detection limit.

The organic protective layer 72 was made of the sample N of Example 1.
o.

As described above, a simple matrix type organic EL color display was completed.

In this color display, Embodiment 1
As in the case of the sample of the present invention, no decrease in initial luminance and no increase in drive voltage were observed. Further, the dark spot and the luminance half life were also the same as those of the sample of the present invention of Example 1.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration example of an organic EL display device of the present invention.

FIGS. 2A to 2F are plan views for explaining a manufacturing process of the organic EL display device.

FIGS. 3A to 3F are cross-sectional views illustrating a manufacturing process of the organic EL display device.

FIGS. 4A and 4B are cross-sectional views for explaining a mask 8 having a structure different from that of the mask 8 of FIGS. 2 and 3;

5A is a cross-sectional view for explaining a gradient at an end of a conductive inorganic material layer 71, and FIG. 5B is a cross-sectional view for explaining a gradient at an end of an anode 2. FIG.

6A is a plan view of a dot matrix display, FIG. 6B is a plan view showing a position of an opening of a mask 8 in a manufacturing process of the dot matrix display of FIG. 6A, and FIG. 3 is a sectional view of FIG.

FIG. 7 (a-1) to (d-1) show a dot matrix.
It is a top view for explaining the manufacturing process of a display, and (a-2)-(d-2) is (a-1)-(d-1).
FIG.

FIGS. 8 (a-1) and (b-1) show a dot matrix.
It is a top view for explaining the manufacturing process of a display, and (a-2), (b-2), (b-3), and (c).
Is a sectional view.

FIGS. 9A to 9E are cross-sectional views illustrating a process for manufacturing a color display.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 11 Overcoat layer 2 Anode 21 Terminal part 3 Terminal electrode 4 Insulating layer 5 Organic functional layer 6 Cathode 7 Protective layer 71 Conductive inorganic material layer 72 Organic protective layer 8 Mask 81 Shield part 82 Base part 9 Cap type structure 91 Al layer 92 Cr layer

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Mitsunari Suzuki 1-13-1 Nihonbashi, Chuo-ku, Tokyo Inside TDK Corporation

Claims (7)

[Claims] 1. A light emitting unit laminate having on a substrate surface, the light emitting unit laminate includes an anode, an organic functional layer including a light emitting layer,
A cathode and a protective layer in this order; the protective layer includes a conductive inorganic material layer and an organic protective layer formed thereon; and the organic protective layer is a carbon fluoride layer containing chlorine. It is formed by a vacuum deposition method using at least one polymer selected from coalescing as a deposition source,
An organic electroluminescent display device formed by a sputtering method using a kind of polymer as a target. 2. The method according to claim 1, wherein the conductive inorganic material layer is made of Ag, Al,
Whether it is made of any one of Au, Cr, Mo, Pt, Ti and W, or made of an alloy of at least one of Cu, Mo, Sc, Si and W and Al;
TiN, ZnO, organic electroluminescent display device according to claim 1 which is composed of SnO ₂ or In ₂ O _3. 3. The organic electroluminescent display device according to claim 1, wherein the cathode is made of a metal having a work function of 4 eV or less. 4. A substrate having a terminal electrode on a surface thereof, wherein the conductive inorganic material layer is a wiring layer in contact with at least a part of the terminal electrode, and a gradient of an end of the conductive inorganic material layer is:
It is 0.1 or less at least near the terminal electrode.
3. The organic electroluminescent display device according to any one of 3. 5. A method for manufacturing an organic electroluminescent display device according to claim 1, wherein after forming an anode and a terminal electrode, a shielding portion for limiting a layer forming region and a shielding portion surrounding the shielding portion are provided. A mask having an opening, the substrate is placed so that the surface side thereof is opposed, then an organic functional layer and a cathode are formed, and then, the step coverage is higher than the method used for forming the organic functional layer. A method for manufacturing an organic electroluminescent display device in which a conductive inorganic material layer is formed by a favorable method so that the conductive inorganic material layer is in contact with at least a part of a terminal electrode. 6. The method for manufacturing an organic electroluminescent display device according to claim 5, wherein the substrate is placed on the mask such that the shielding portion of the mask covers at least a part of the terminal electrode via a space. 7. An organic functional layer is formed by a vacuum deposition method,
6. The conductive inorganic material layer is formed by a sputtering method.
Or 6) the method of manufacturing an organic electroluminescence display device.