JP2001076870A - Method for forming display pattern of organic el element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming a display pattern of an organic EL element, allowing the formation of various display patterns in simple processes. SOLUTION: After a positive electrode 23 and a luminescent layer 221 are layered in sequence on a transparent substrate 1 or a negative electrode is further layered thereon, a high energy beam (electron beam of 1 keV or more) is applied to a predetermined portion of the luminous layer 221 for deenergizing the luminescence of the portion to form a luminescence deenergized portion 221b. With the existance of a portion which is a luminescence deenergized portion 221a of the luminescent layer 221, where no high energy beam is radiated, and which is located between the positive electrode 23 and the negative electrode, a double-circular display pattern 6 is formed with an internal circular pattern 62 independently located inside an external circular pattern 61.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method for forming a display pattern (light emission pattern) of an organic electroluminescence (EL) element. INDUSTRIAL APPLICATION This invention is utilized for the organic EL element etc. which perform the light emission display by a fixed pattern.

[0002]

2. Description of the Related Art Conventionally, as a method of forming a display pattern in an organic EL device which performs light-emitting display by a fixed pattern, one electrode and a light-emitting layer of an anode and a cathode are formed solid, and the other electrode is displayed. There is known a method in which a voltage is applied to only a portion of a light emitting layer corresponding to a display pattern to emit light by forming the light emitting layer in a pattern shape.
In Japanese Patent Application Laid-Open No. 10-284254, an insulating layer patterned so as to have a through hole cut out in a display pattern shape is provided between both electrodes, and a portion other than the light emitting pattern is illuminated by the insulating layer. Organic E not to be
An L element is disclosed.

[0003]

All of the above prior arts require a step of forming an electrode or an insulating layer in a predetermined pattern. As this method, there are a method using a deposition mask, a method using photolithography, and the like. But,
According to the method using an evaporation mask, when a pattern having another pattern independently positioned inside the annular pattern (for example, a double-circle pattern) or the like is formed, one evaporation mask is used. Since it cannot be formed, a plurality of evaporation steps must be performed using a plurality of evaporation masks. On the other hand, the photolithography method has a high degree of freedom in the pattern shape to be applied, but requires many man-hours such as resist pattern formation, exposure, and etching, and may cause a light emission defect due to a resist residue.

An object of the present invention is to provide a method for forming a display pattern of an organic EL device, which can form various display patterns by a simple process.

[0005]

In order to solve the above-mentioned problems, the present invention provides a method for forming a display pattern of an organic EL device, which comprises irradiating a predetermined portion of a light emitting layer with a high energy ray to emit light from the portion. It is characterized by deactivating.

The high energy beam includes an electron beam, X
Light, ultraviolet light, laser light, or the like can be used. Among them, it is particularly preferable to use an electron beam in terms of irradiation efficiency, irradiation accuracy, and ease of handling. The intensity of the electron beam is preferably 1 keV or more as in the third invention, more preferably in the range of 1 keV to 10 keV, and more preferably 1 kV.
The range of eV to 2 keV is more preferable.

The irradiation of the high energy beam may be performed after the anode and the light emitting layer are sequentially laminated on a transparent substrate in a process of manufacturing an organic EL device as in the second invention.
Alternatively, it may be performed after further laminating the cathode. In addition, high energy rays may be irradiated from the display side (transparent substrate side) of the light emitting layer, or may be irradiated from the side opposite to the display side (cathode side). Examples of a method of irradiating a high energy ray include a method of drawing by scanning a finely squeezed high energy ray, a method of using an irradiation mask made of a material that does not transmit the high energy ray, a method of using these in combination, and the like. .

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described more specifically by way of examples. (1) Configuration of Organic EL Element FIG. 6 shows an organic EL element obtained by forming a display pattern by the method of the present invention. The organic EL element is joined to a transparent substrate 1, an organic EL laminated film 2 formed on the transparent substrate 1, and
And a sealing member 4 for sealing the laminated film 2. At the time of light emission, as shown in FIG. 7, a double circular display pattern 6 composed of an outer circle pattern 61 and an inner circle pattern 62 is displayed.

The transparent substrate 1 is made of soda-lime glass having a thickness of 1.1 mm. As the transparent substrate 1, in addition to glasses such as soda-lime glass, a plate, sheet, or film made of a transparent material such as resin and quartz can be used. Among them, it is particularly preferable to use a glass plate.

An organic EL laminated film 2 is formed on a transparent substrate 1
An anode 21 made of TO, an organic EL film 22, and a cathode 23 made of an aluminum alloy are laminated. The organic EL film 22 includes, in order from the cathode 23 side, an electron injection layer made of LiF, an electron transport layer made of an aluminum quinolium complex, a light emitting layer 221 doped with quinacridone using an aluminum quinolium complex as a host, and TPTE (triphenylamine A hole transport layer (not shown) composed of a tetramer) and a hole injection layer (not shown) composed of a copper phthalocyanine complex are laminated. Note that the organic EL film 22 is
21 and may have a hole transport layer and / or an electron transport layer in addition to the light emitting layer, and may further have a hole injection layer and / or an electron injection layer. 1 and 3 to 3
6, only the light emitting layer 221 is schematically shown as the organic EL film 22.

The light-emitting layer 221 includes a light-emitting active portion 221a having a light-emitting function and a light-emitting inactivating portion 221b having light emission deactivated by irradiating an electron beam as described later.
Consists of A portion (a portion that can emit light by applying a voltage) between the ITO electrode 21 and the cathode 23 in the light emitting active portion 221a causes the outer circular pattern 61 to be positioned inside the outer circular pattern 61 and from the outer circular pattern 61 A double-circle display pattern 6 including an independent inner circle pattern 62 is formed. In addition, as a material constituting each layer of the anode 21, the cathode 23, and the organic EL film 22, various known materials other than those described above can be used. In addition, methods for forming these layers include a vacuum evaporation method, a spin coating method,
What is necessary is just to select suitably from well-known methods, such as a casting method, a sputtering method, and LB method.

As the sealing member 4, one or two kinds of metals such as stainless steel, aluminum or alloy thereof, glasses such as soda lime glass and silicate glass, and resins such as acrylic resin and styrene resin are used. What consists of the above can be used. In this embodiment, the sealing member 4
Is a soda-lime glass having a thickness of 1.1 mm. The joining between the sealing member 4 and the transparent substrate 1 is performed by using an epoxy resin adhesive, an acrylate adhesive, a thermosetting resin,
It can be performed using an adhesive such as a photocurable resin. Among them, those that form a cured product having low permeability to moisture and the like are preferable. Further, a photocurable resin is preferably used because it is excellent in the reduction of thermal stress to the element and the rapid curability.
In the present embodiment, the peripheral portion 41 of the sealing member 4 is joined to the transparent substrate 1 by an adhesive portion 5 formed by curing an adhesive made of an electrically insulating photocurable resin, thereby forming an organic EL. The laminated film 2 is hermetically sealed.

(2) Method of Manufacturing Organic EL Device The organic EL device having the above structure can be manufactured as follows. An ITO film for the anode 21 and the electrode lead 23a is formed on the transparent substrate 1 (FIG. 2).
Then, an organic EL film 22 made of a material such as 21 is formed (FIG. 3). At this stage, the entire surface of the light emitting layer 221 has a light emitting function (that is, the light emitting deactivating portion 221b has not been formed yet). Next, as shown in FIG. 1, from the side opposite to the transparent substrate 1, the light emitting layer 221 located on the anode 21 and a portion other than the display pattern 6 are irradiated with an electron beam having an intensity of 1 keV by a scanning method. . Thereby, the light emitting layer 221 in the portion irradiated with the electron beam loses the light emitting function and changes to the light emitting inactivating portion 221b. The portion not irradiated with the electron beam becomes the light emitting active portion 221a. FIG. 4 is a view taken in the direction of the arrow X in FIG. 1, and the hatched area indicates the light emission deactivating portion 221 b formed by electron beam irradiation.

Thereafter, as shown in FIG.
An aluminum alloy film for the cathode 23 is formed from above, and the sealing member 4 is further joined to obtain the organic EL device shown in FIG. When a voltage is applied to the organic EL element, a portion of the light emitting active portion 221a sandwiched between the anode 21 and the cathode 23 emits light, and a display pattern 6 including an outer circle pattern 61 and an inner circle pattern 62 is displayed. You.

In this embodiment, the electron beam is irradiated only on the portion other than the light emitting pattern of the light emitting layer and between the anode and the cathode (the portion to which a voltage is applied) to deactivate the light emission. However, the electron beam may also be applied to the light emitting layer in a portion other than the light emitting pattern and not between the anode and the cathode. In the case where the organic EL film has an electron injection layer, an electron transport layer, and the like in addition to the light emitting layer, the light emitting layer may be irradiated with an electron beam before or after laminating these layers on the light emitting layer. You may. Further, in the above embodiment, the electron beam is irradiated before forming the cathode, but the electron beam may be irradiated after forming the cathode on the organic EL film. Also in this case, the display pattern can be formed by deactivating the light emitting layer in the irradiated portion.

[0016]

The display pattern forming method of the present invention is different from the conventional technique of forming an electrode having a display pattern shape and the conventional technique of forming an insulating layer having a through hole having the shape of a display pattern. A display pattern is formed by irradiating a predetermined portion of the light emitting layer with a high energy beam such as an electron beam to inactivate light emission. According to this method, even if the pattern has another pattern independently positioned inside the annular pattern (for example, a double circular pattern), a resist pattern is formed or a plurality of evaporation masks are used. Can be created without having to do so. Therefore, the manufacturing process can be simplified, and the resist residue does not adversely affect light emission. Further, since the irradiation position can be accurately controlled as in the case of the electron beam lithography technology in the semiconductor field, a fine display pattern can be formed with high accuracy. Further, since there is no step between the portion forming the display pattern and the portion other than the display pattern in the light emitting layer, it is easy to uniformly form the cathode and the like on the light emitting layer.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a stage in which a light emitting layer is irradiated with an electron beam to form a light emitting deactivating portion in an example.

FIG. 2 is a plan view showing a stage in which an ITO film is formed in an example.

FIG. 3 is a longitudinal sectional view showing a stage in which a light emitting layer is formed in an example.

FIG. 4 is a view as seen in the direction of arrow X in FIG. 1;

FIG. 5 is a plan view showing a stage in which a cathode is formed in an example.

FIG. 6 is a longitudinal sectional view showing an organic EL device manufactured according to an example.

FIG. 7 is a plan view of the organic EL device manufactured according to the example when viewed from the transparent substrate side during light emission.

[Explanation of symbols]

1; transparent substrate, 2; organic EL laminated film, 21; anode, 2
2, organic EL film, 221; light emitting layer, 221a; light emitting active portion, 221b; light emitting deactivating portion, 23; cathode, 4; sealing member, 6; display pattern, 61; outer circle pattern, 62;

Claims (3)

[Claims] 1. A method for forming a display pattern of an organic EL device, comprising irradiating a predetermined portion of a light emitting layer with a high energy beam to deactivate light emission of the portion. 2. The method for forming a display pattern of an organic EL device according to claim 1, wherein the irradiation with the high energy beam is performed after sequentially stacking an anode and the light emitting layer on a transparent substrate, or after further stacking a cathode. . 3. The method according to claim 1, wherein the high energy beam is an electron beam of 1 keV or more.