JP2003297568A - Method for manufacturing organic electroluminescent display device - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To provide a plurality of lower electrodes 12 formed in an elongated stripe pattern formed on a surface 11a of a transparent electrode 11, an organic electroluminescent layer 13, and a number of upper electrodes 14 formed in an elongated stripe pattern. In an organic electroluminescent display device comprising a cap body 15 fixed to the surface of the transparent substrate 11 so as to seal them, the upper electrodes 14 are patterned by irradiating a metal film 18 with a laser beam. In this case, the patterning process is easily performed at low cost. The laser beam is applied to the cap body (15).
The metal film 19 sealed in is irradiated from the back surface 11b side of the transparent substrate 11.

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to an organic electroluminescent display device (organic EL device) having an electroluminescent layer (organic EL layer) which emits light by applying a current.
Display device). 2. Description of the Related Art Generally, as shown in FIGS. 1 to 3, an organic electroluminescent display device of this type has a transparent substrate 11 made of glass or the like, and a lower electrode 12 made of a transparent material on a surface 11a thereof. Are formed in an elongated stripe pattern, an electroluminescent layer 13 is formed on the lower electrode 12, and a plurality of upper electrodes 14 made of a metal film are formed on the electroluminescent layer 13. Is formed in an elongated stripe pattern in a direction intersecting with the lower electrode 13, and the entire lower electrode 12, the organic electroluminescence layer 13, and each upper electrode 14 are hermetically sealed on the surface 11 a of the transparent substrate 11. Is fixed with an adhesive 16 such as an epoxy resin. By applying a current between a desired lower electrode and any of the upper electrodes 14 to emit light from the electroluminescence layer 13 between the lower electrode and the upper electrode 14, the electroluminescent layer 13 emits light at the portion between the lower electrode and the upper surface of the transparent substrate 11. In addition, characters and the like are displayed. [0003] In FIGS.
Represents a lead electrode for each of the lower electrodes 12,
Reference numeral 18 indicates a lead electrode for each of the upper electrodes 14, and these lead electrodes 17, 18 extend outside the cap body 15. Conventionally, when manufacturing an organic electroluminescent display device having this configuration, first, a lower electrode 12 is formed on a surface 11a of the transparent substrate 11, and an organic electroluminescent layer 13 is superposed thereon. Is formed on the surface of the organic electroluminescence layer 13 by forming a metal film for the upper electrode into a thin film by sputtering or the like, and a predetermined stripe pattern is formed on the metal film using a shadow mask. After baking, a method of forming an upper electrode 14 by removing a portion of the metal film other than a predetermined stripe pattern by etching, or adopting a method of forming a lower electrode 12 on the surface 11a of the transparent substrate 11 After forming a cathode partition layer, the cathode partition layer is photo-etched to form an upper electrode. Patterned into Ri, during the cathode barrier layer, after forming the organic electroluminescent layer 13, the surface of the cathode partition layer adopts a method of forming the upper electrode 14. [0005] However, in the former method, the upper electrode 14 is formed by baking using a shadow mask, so that the upper electrode 14 may be misaligned. In addition, the latter method requires a complicated process of photoetching, which leads to a significant increase in cost. Accordingly, Japanese Patent Laid-Open No. 5-30 as a prior art is disclosed.
In order to solve these problems, Japanese Patent Application Laid-Open No. 77-107 discloses a method of directly irradiating a laser beam directly to a metal film for an upper electrode formed on the surface of the electroluminescent layer 13 so that a predetermined portion of the metal film is A patterning method using a laser beam has been proposed in which portions other than the stripe pattern are removed by thermal processing using laser beam irradiation. [0007] This prior art method of patterning an upper electrode by using a laser beam has a relatively simple process, and
It has the advantage of improving the positional accuracy between the two electrodes, but on the other hand, irradiates the laser beam directly to the metal film for the upper electrode before fixing the cap on the front side of the transparent substrate Therefore, when the patterning process using the laser beam is performed in the air, the organic electroluminescent layer 13 is deteriorated by the air and moisture in the air, or the upper electrode is oxidized. In other words, the display quality is degraded. Therefore, in order to avoid this situation, it is necessary to perform the patterning process using a laser beam in a sealed container in a state where it is almost completely shielded from the atmosphere. In addition to the necessity of a container, it is necessary to put the container in and out of the closed container, and there has been a problem that the production cost is greatly increased. According to the present invention, in manufacturing an organic electroluminescence display element, it is extremely simple to form a large number of upper electrodes by patterning with a laser beam without causing the above-mentioned problems. It is a technical task to do so. In order to achieve this technical object, the present invention provides a method of forming at least a plurality of transparent lower electrodes on the surface of a transparent substrate in an elongated stripe pattern. Forming an organic electroluminescent layer on the surface of the transparent substrate so as to overlap the lower electrode, forming an upper electrode metal film on the organic electroluminescent layer, and forming a surface of the transparent substrate on the surface of the transparent substrate. The lower electrode, an organic electroluminescence layer and a step of fixing a cap that seals the whole of the metal film, further comprising, after the step of fixing the cap, the metal film for the upper electrode, By irradiating a laser beam onto the metal film from the back side of the transparent substrate, patterning processing is performed on a large number of upper electrodes having an elongated stripe pattern. It is characterized by that. As described above, the present invention provides a method of patterning a metal film for an upper electrode formed on an organic electroluminescence layer into a plurality of upper electrodes having a long and narrow stripe pattern. After fixing the cap for sealing the entirety of the organic electroluminescent layer or the like on the surface of the transparent substrate, by performing the irradiation by the laser beam from the back side of the transparent substrate, by the laser beam The patterning process on the upper electrode can be performed in an organic electroluminescence display device in a state in which the upper electrode is shielded from the atmosphere by using a cap body fixed to the surface side of the transparent substrate. Therefore, according to the present invention, the use of a large hermetic container for patterning the upper electrode by the laser beam is not required, and the need for taking in and out of the hermetic container is not required. Having. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. First, as shown in FIG. 4, a transparent substrate 11 made of glass or transparent synthetic resin has a surface 11a.
In the same manner as before, a large number of transparent lower electrodes 12 are formed in an elongated stripe pattern by sputtering or photolithography, etc., and a lead electrode 17 for each of the lower electrodes 12 is formed as described below. The lead electrode 18 for each of the upper electrodes 14 to be formed is similarly formed of a transparent body. Next, as shown in FIG. 5, an organic electroluminescent layer 13 is formed on the surface 11a of the transparent substrate 11 by vapor deposition or the like in the same manner as in the prior art.
2 is formed. In this case, in another embodiment, the organic electroluminescent layer 13 is formed by using a hole transport layer which is formed on the lower electrode 12 before the organic electroluminescent layer 13 as a base, and Alternatively, they may be formed so as to overlap. Next, as shown in FIGS. 6 and 7, a metal film 19 for an upper electrode made of a manganese-silver alloy or aluminum or the like is formed on substantially the entire organic electroluminescent layer 13 by sputtering or vacuum evaporation. Then, the metal film 19 is formed so as to overlap with each lead electrode 18 of the upper electrode. Next, as shown in FIG. 8, each of the lower electrodes 12, the organic electroluminescent layer 13, and the metal film 19 are formed on the surface 11a of the transparent substrate 11, as shown in FIG.
Metal or synthetic resin cap body 15 for sealing the whole
Is fixed with an adhesive 16 such as an epoxy resin. The cap body 15 is filled with an inert gas such as a nitrogen gas. Then, as shown in FIG. 9, the transparent substrate 11 has its back surface 11b facing upward, and a laser beam from a laser beam source 20 disposed thereabove is applied to the back surface 11b of the transparent substrate 11. Is irradiated downward. Then, the laser beam passes through the transparent substrate 11, the transparent lower electrode 12, and the organic electroluminescence layer 13, reaches the metal film 19, and the portion of the metal film 18 where the laser beam hits Disappears by thermal processing. Therefore, by scanning the laser beam in a direction intersecting with each of the lower electrodes 12 from a portion between the respective lead electrodes 18, it is possible to form a plurality of upper electrodes 14 having an elongated stripe pattern. It is. The laser beam is focused on the metal film 19 using a lens (not shown), so that the patterning of the metal film 19 by the laser beam can be performed reliably and accurately. It can be carried out. Thus, the metal film 19 for the upper electrode is formed.
Of the upper electrode 14 having a long and narrow stripe pattern by irradiating the metal film 19 with a laser beam, it is possible to form the upper electrode 14 in the cap body 15 fixed on the surface 11 a of the transparent substrate 11 into an atmosphere. It can be performed in a state completely shut off from the air.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical sectional front view showing an organic electroluminescence display device. FIG. 2 is a sectional view taken along line II-II of FIG. FIG. 3 is a perspective view of the inside of the organic electroluminescence display device. FIG. 4 is a perspective view showing a state in which a lower electrode is formed on a transparent substrate in the present invention. FIG. 5 is a perspective view showing a state in which an organic electroluminescent layer is formed on a transparent substrate so as to overlap the lower electrode in the present invention. FIG. 6 is a perspective view showing a state in which a metal film is formed on a transparent substrate so as to overlap the organic electroluminescence layer in the present invention. FIG. 7 is an enlarged sectional view taken along line VII-VII of FIG. 6; FIG. 8 is a cross-sectional view showing a state where a cap body is fixed to a transparent substrate in the present invention. FIG. 9 is a cross-sectional view showing a state where the metal film is being patterned by a laser beam in the present invention. DESCRIPTION OF SYMBOLS 11 Transparent substrate 12 Lower electrode 17, 18 Lead electrode 14 Upper electrode 13 Organic electroluminescence layer 19 Metal film 15 Cap body 16 Adhesive 20 Laser beam source

Claims (1)

Claims 1. At least a step of forming a large number of lower electrodes of a transparent body in an elongated stripe pattern on a surface of a transparent substrate, and forming an organic electroluminescence layer on the surface of the transparent substrate. Forming a metal film for an upper electrode on the organic electroluminescent layer; and forming the lower electrode, the organic electroluminescent layer and the metal film on the surface of the transparent substrate. Fixing a cap body for sealing the whole, and further comprising, after the step of fixing the cap body, applying a laser beam to the metal film for the upper electrode from the back surface side of the transparent substrate. An organic electroluminescent display device characterized by patterning a large number of elongated strip-shaped upper electrodes by irradiating light. Manufacturing method.