Electric lamp and discharge devices – With luminescent solid or liquid material – Solid-state type
Reexamination Certificate
1999-01-14
2001-06-19
Patel, Nimeshkumar D. (Department: 2879)
Electric lamp and discharge devices
With luminescent solid or liquid material
Solid-state type
Reexamination Certificate
active
06249084
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention:
The present invention relates to an electroluminescence display panel in which light-emitting elements utilizing the electroluminescence of an organic material are arranged in a matrix, and a method for producing the same.
2. Description of the Related Art:
An electroluminescence display panel in which an organic material for obtaining electroluminescence and metal electrodes (serving as upper electrodes) for transferring a current are subsequently deposited by a vacuum vapor deposition method on a glass substrate with patterned ITO (indium tin oxide) transparent electrodes (serving as lower electrodes) is known.
In such a display, light is emitted from the portions of the organic material which are interposed between the ITO electrodes and the metal electrodes. In the case where the ITO electrodes and the metal electrodes are both patterned into a stripe shape, and arranged so as to intersect each other (e.g., orthogonal to each other), an electroluminescence display panel capable of providing a dot-matrix display can be obtained.
For fabricating such a display panel, the metal electrodes are patterned by depositing a metal material on the substrate through a metal mask having desired opening patterns. However, patterning the metal electrodes using a metal mask has the following problems.
In the case of the metal mask for forming stripe patterns for providing image display, the metal mask has a large open area and a small mask portion. Such a metal mask thus has a poor mechanical strength. Therefore, the metal mask is likely to be bent and partially separated from the substrate surface.
When the metal mask is partially separated from the substrate surface and a gap is produced therebetween, a material being deposited is introduced into the gap, thereby causing defective patterns of the metal electrodes or the like. This leads to a serious problem particularly when small patterns are formed over a large area.
A method for forming a metal film to pattern metal electrodes by photolithography techniques is possible in order to solve the above-mentioned problem.
However, this method raises another problem as follows: the organic material may be damaged by a solvent of a resist solution, a developer and an etchant, or by plasma in the case of a dry etching method, whereby characteristics of the light-emitting elements (light-emitting portions) may be degraded.
Moreover, a method for producing an electroluminescence display panel by using a technique of obliquely supplying an upper electrode material onto a substrate having a plurality of stripe-shaped insulation films is described in Japanese Laid-open Publication No. 5-2058859. In this method, however, vapor of the metal electrode material may be undesirably directed to the sides of the insulation films, thereby hindering desirable patterning.
SUMMARY OF THE INVENTION
According to one aspect of the present invention, an electroluminescence display panel includes: a substrate; a plurality of stripe-shaped lower electrodes formed adjacent and spaced apart from each other on the substrate so as to extend in a first direction; a plurality of stripe-shaped insulation films formed spaced apart from each other on the stripe-shaped lower electrodes so as to extend in a second direction which crosses the first direction, each of the stripe-shaped insulation films having a groove extending in the second direction; a plurality of organic films for providing electroluminescence formed over the plurality of stripe-shaped lower electrodes and the plurality of stripe-shaped insulation films, the plurality of organic films being separated from each other by the grooves of the stripe-shaped insulation films; and an upper electrode being formed from an electrically conductive film and formed on the organic film.
In one example, a plurality of the grooves are formed in each of the stripe-shaped insulation films so as to extend in the second direction.
In one example, the stripe-shaped insulation films are formed from a water-resisting material.
In one example, the stripe-shaped insulation films are formed from a moisture-absorbing material.
In one example, the upper electrodes do not reach respective ends of the stripe-shaped insulation films, the ends of the stripe-shaped insulation films being located along the second direction.
According to another aspect of the present invention, an electroluminescence display panel includes: a substrate; a plurality of stripe-shaped lower electrodes formed spaced apart from each other on the substrate so as to extend in a first direction; a plurality of stripe-shaped insulation films formed spaced apart from each other on the stripe-shaped lower electrodes so as to extend in a second direction which is perpendicular to the first direction, at least one recess being formed in a side surface of each stripe-shaped insulation film; an organic film for providing electroluminescence, the organic film being formed at least on each lower electrode located between the stripe-shaped insulation films which are adjacent to each other, and the stripe-shaped insulation films, and the organic film being separated by the recess; and an upper electrode being formed from an electrically conductive film and formed on the organic film.
In one example, each of the stripe-shaped insulation films has a cross sectional width broadening toward its bottom, and a protruding portion is formed at a lowermost portion of each of the stripe-shaped insulation films.
In one example, each of the stripe-shaped insulation films includes alternate layers of insulation materials having different etching rates.
In one example, a first alternate layer is formed from a water-resisting material and a second alternate layer is formed from a moisture-absorbing material.
In one example, at least one groove is formed in a surface of each stripe-shaped insulation film.
In one example, the upper electrodes do not reach respective ends of the stripe-shaped insulation films, the ends of the stripe-shaped insulation films being located along the second direction.
In one example, the upper electrodes are formed after the stripe-shaped lower electrodes and the stripe-shaped insulation films are sequentially formed on the substrate, the upper electrodes being formed by supplying the electrically conductive material onto the substrate at a prescribed angle from an axis perpendicular to a surface of the substrate.
In one example, the groove is formed in a surface of each stripe-shaped insulation film by forming a groove in the surface of each stripe-shaped insulation film or by locating a pair of stripe-shaped insulation films close to each other.
In one example, the at least one recess is formed in a side surface of each stripe-shaped insulation film by etching.
In one example, at least the upper electrodes are formed by supplying the electrically conductive material from a direction substantially perpendicular to a surface of the substrate.
In one example, the stripe-shaped insulation films are formed by lifting off a resist formed before depositing the stripe-shaped insulation films.
Thus, the invention described herein makes possible the advantages of (1) providing an electroluminescence display panel capable of patterning upper electrodes without using a metal mask, thereby readily achieving smaller patterns and larger display area, as well as a method for producing the same; (2) providing an electroluminescence display panel capable of patterning the upper electrodes without using photolithography techniques after light-emitting portions are formed, thereby achieving improved reliability without damaging the light-emitting portions, as well as a method for producing the same; (3) providing an electroluminescence display panel having an insulation film with a simple structure, thereby achieving improved production efficiency of the insulation film, and reduction in cost, as well as a method for producing the same; (4) providing an electroluminescence display panel capable of improving uniformity of the depo
Hopper Todd Reed
Patel Nimeshkumar D.
Sharp Kabushiki Kaisha
LandOfFree
Electroluminescence display panel and production method of... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electroluminescence display panel and production method of..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electroluminescence display panel and production method of... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2514368