JP2003133077A - Organic el panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic EL panel capable of suppressing nonuniform luminance in a luminescent region on a display panel. SOLUTION: This organic EL panel 1 is structured by disposing an organic EL element (laminate) 8 formed by holding at least an organic layer having an luminescent layer 5 between a non-translucent back plate 6 and a translucent transparent electrode (front electrode) 3 on a translucent glass base (supporting base) 2, and is composed of the back plate 6 formed as a common electrode, the transparent electrode 3 formed so that the luminescent layer generates prescribed luminescence by giving a fixed current, and a slit 6c provided on the front electrode 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a laminated body in which an organic layer having at least a light emitting layer is sandwiched between a non-translucent back electrode and a translucent front electrode on a translucent support substrate. The present invention relates to an organic EL (electroluminescence) panel.

[0002]

2. Description of the Related Art As an organic EL panel, ITO is formed on a glass substrate (translucent supporting substrate) made of a glass material.
A transparent electrode (front electrode) that becomes an anode by (indium tin oxide), an organic layer that consists of a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer, and a non-electrode such as aluminum (Al) that becomes a cathode. An organic EL element that is a laminated body is formed by sequentially laminating a translucent back electrode, and a sealing member made of a glass material that covers the laminated body is hermetically sealed on the glass substrate via an ultraviolet curable adhesive. What is arranged in a known manner is known.

As such an organic EL panel, a single back electrode serving as a common electrode (common electrode) is provided, and a transparent electrode (eg, a letter-shaped segment corresponding to a constant current) is formed in each light emitting region. There is one using a so-called static drive system in which it is selectively applied to the transparent electrode).

[0004]

The back electrode in such an organic EL panel is formed to be slightly smaller than the formation region of the organic layer in order to avoid contact with the transparent electrode. To electrically connect to the electrode terminals (terminals made of the same material as the transparent electrodes) formed on the end portions of the glass substrate for the purpose of connecting the transparent electrodes, so that they do not make electrical contact with the transparent electrodes. In this state, it is formed by drawing on the glass substrate. In the organic EL panel having such a configuration of the back electrode, as the panel size increases, the contact portion of the back electrode with the electrode terminal and the glass substrate also increases, and the back electrode, especially the contact portion, has a high temperature. At the time of or low temperature, it will be displaced with respect to the glass substrate due to the difference in thermal expansion between the glass substrate and the electrode terminal, because the contact portion will be fixed to the glass substrate, The displacement of the back electrode causes a forced displacement in the light emitting region of the organic layer to generate stress, and this stress causes a problem of uneven brightness of the light emitting region particularly in a high temperature environment. Was.

Therefore, the present invention focuses on the above-mentioned problems and provides an organic EL panel capable of suppressing the occurrence of luminance unevenness in a light emitting region of a display panel.

[0006]

In order to solve the above problems, the present invention provides a laminated body in which an organic layer having at least a light emitting layer is sandwiched between a non-translucent back electrode and a translucent front electrode. An organic EL panel arranged on an optical support substrate, wherein the back electrode is provided with slits.

An organic EL panel in which a laminated body in which an organic layer having at least a light emitting layer is sandwiched between a non-translucent back electrode and a translucent front electrode is disposed on a translucent support substrate. Where the back electrode is formed as a common electrode, the front electrode is formed so that the light emitting layer emits light in a predetermined manner by selectively applying a constant current, and a slit provided in the back electrode. And are composed of.

Further, the slit is formed at least in the vicinity of the contact portion of the back electrode with the supporting substrate, or at least in the vicinity of the contact portion of the back electrode with the electrode terminal. is there.

The back electrode is composed of a metal electrode having a thickness of 150 nm or less.

Further, the slit provided in the back electrode is formed by any one of a vapor deposition method, laser processing, and an electrically insulating partition wall.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

A first embodiment of the present invention will be described with reference to FIGS. 1 and 2, an organic EL panel 1 includes a glass substrate (supporting substrate) 2, a transparent electrode (front electrode) 3, an insulating layer 4, an organic layer 5, and a back electrode (second electrode).
It is mainly composed of an electrode 6 and a sealing member 7.

The glass substrate 2 is a translucent support substrate having a rectangular shape.

The transparent electrode 3 is formed of a conductive material such as ITO on the glass substrate 2 by a method such as a vapor deposition method or a sputtering method.
a, a lead portion 3b formed by drawing out from each display segment portion 3a, and an electrode terminal 3c provided at the end portion of the lead portion 3b. A structure capable of selectively applying the constant current of is obtained. The electrode terminals 3c are formed by drawing out lead portions 3b corresponding to the respective display segment portions 3a so as to be concentratedly arranged on one side of the glass substrate 2.

The insulating layer 4 is made of, for example, an insulating material such as polyimide, and is formed by means such as photolithography. The insulating layer 4 has a window portion 4a corresponding to the display segment portion 3a, and in order to clearly display the outline of the light emitting region, the window portion 4a is formed so as to slightly overlap the peripheral portion of the display segment portion 3a of the transparent electrode 3. Formed and also
In order to ensure the insulation between the transparent electrode 3 and the back electrode 6, it is arranged so as to cover the lead portion 3b.

The organic layer 5 may have at least a light emitting layer, but in the embodiment of the present invention, the hole injection layer, the hole transport layer, the light emitting layer and the electron transport layer are formed by a method such as vapor deposition. Are sequentially laminated.

The back electrode 6 is made of a metal conductive material such as aluminum (Al), aluminum lithium (Al: Li), and magnesium silver (Mg: Ag) with a thickness of 150 nm or less by means such as vapor deposition or sputtering. It is formed on the organic layer 6 with a film thickness, is a single metal electrode having a rectangular shape, and serves as a common electrode of the light emitting portion (display segment portion 3a) in the organic layer 5. The back electrode 6 is electrically connected to a cathode electrode terminal 6 a provided on one side of the glass substrate 2 so as to be adjacent to each electrode terminal c of the transparent electrode 3. The electrode terminal 6
The a is made of the same material as the transparent electrode 3 and is formed in an elongated shape along the width direction of the back electrode 6.

The back electrode 6 is, as shown in FIG.
Electrode terminal 6 for cathode of display segment portion (light emitting portion) 3a
Since it is electrically connected to a, one side is formed slightly larger than the insulating layer 4 and the organic layer 5, and the electrode terminal 6
A contact portion 6b is provided so as to overlap with a and the glass substrate 2. In addition, the back electrode 6 has a plurality of slit portions 6c along the longitudinal direction of the back electrode 6, and the display segment portion 3a.
Is provided in a state excluding the formation region. The slit portion 6c is formed by, for example, sequentially laminating the transparent electrode 3, the insulating layer 4, the organic layer 5, and the back electrode 6, and then laser machining the visible region wavelength from the back electrode 6 made of a non-translucent metal material. Or by vapor deposition. Further, in the slit portion 6c in the first embodiment of the present invention, for example, the formation interval in the width direction of the back electrode 6 is 0.65 mm, and the slit width is 10 to 20 μ.
I am m.

The back electrode 6 is formed on the insulating layer 4 in a state in which one side is provided on the glass substrate 2 but the other side hardly contacts the glass substrate 2.

As described above, the organic EL element 8 is obtained by sequentially laminating the transparent electrode 3, the insulating layer 4, the organic layer 5 and the back electrode 6 on the glass substrate 2 to form a laminated body.

The sealing member 7 is a flat member made of, for example, a glass material and having a recess 7a as a storage portion formed therein. The sealing member 7 is provided with a supporting portion 7b formed so as to surround the recess 7a in an airtight manner on the glass substrate 2 via, for example, an ultraviolet curable epoxy resin adhesive 9, so that the sealing member 7 and The glass substrate 2 constitutes an airtight space 10 for housing the organic EL element 8. The sealing member 7 is slightly smaller than the glass substrate 2 so that the electrode terminal 3c of the transparent electrode 3 and the electrode terminal 6a of the back electrode 6 are exposed to the outside.

The organic EL panel 1 is composed of the above-mentioned parts. A feature of the organic EL panel 1 of the first embodiment is that an organic EL element 8 that is a laminated body in which an organic layer 5 is sandwiched between a transparent electrode 3 and a back electrode 6 is provided on a glass substrate 2. Regarding the panel 1, there is a point in which the rear electrode 6 is provided with a plurality of slit portions 6c.

Therefore, in the organic EL panel 1, the contact portion 6c of the back electrode 6 is arranged and fixed on the glass substrate 2, and the back electrode 6 is attached to the glass substrate 2 and the electrode terminal 6b.
Although the glass substrate 2 is displaced due to the difference in thermal expansion between the organic layer 5 and the glass substrate 2, the stress generated by this displacement can be relieved by the slit portion 6c formed in the back electrode 6, and thus the organic layer 5 of It is possible to suppress the occurrence of uneven brightness in the display segment portion 3c which is a light emitting region. Therefore, since it is possible to suppress the occurrence of uneven brightness in the light emitting region particularly in a high temperature environment, it can be used as a display panel of a vehicle display device used in a severe environment.

Next, a second embodiment of the present invention will be described with reference to FIG. 4. The same or corresponding portions as those of the first embodiment will be designated by the same reference numerals and detailed description thereof will be omitted.

The second embodiment differs from the first embodiment in the structure of the slit portion. That is, in the first embodiment, a plurality of slit portions 6c are formed in the longitudinal direction of the back electrode 6, while in the second embodiment, the mesh-shaped slit portions 11c are excluded from the formation region of the display segment portion 3a. In this state, the back electrode 11 is formed. In the back electrode 11 shown in FIG. 4, a portion indicated by a line is an electrically connected portion, and a portion indicated by a blank is a slit portion 11c. In the figure, 11a
Is an electrode terminal of the back electrode 11 with the feeding circuit, 11
Reference numeral b is a contact portion with the glass substrate 1 and the electrode terminal 11a.

The back electrode 11 can be obtained by vapor deposition using a mesh-shaped shadow mask.

In the second embodiment, similarly to the first embodiment, it is possible to suppress the occurrence of uneven brightness in the display segment portion 3c which is the light emitting region of the organic layer 5.

Except for the slit portions 6c and 11c of the back electrodes 6 and 11 of the first and second embodiments described above, after the transparent electrode is formed on the glass substrate 2, the phenol-based electrically insulating overcoat is formed. By forming the hang-shaped partition wall, the slit portion can be obtained in the back electrode. That is, by sequentially stacking each layer except the transparent electrode on the partition wall, a slit portion using the partition wall can be obtained in the back electrode. The method of forming the partition wall is disclosed in, for example, Japanese Patent Application Laid-Open No. 10-31886.

The slit portions 6c and 11c of the above-described first and second embodiments are the contact portions 6c of the back electrodes 6 and 11.
Was formed in substantially the entire area except for, in the slit portion of the present invention, at least near the contact portion with the glass substrate in the back electrode, or the electrode terminal in the back electrode Even if it is formed at least in the vicinity of the contact portion, it is possible to suppress uneven brightness in the light emitting region of the display panel.

Further, in the above-described first and second embodiments, the slit portions 6c and 11c are provided on the back electrodes 6 and 11 so as not to be formed in the formation region of the display segment portion 3a. It is also possible to form in the region where the light emitting portion is formed by forming a minute hole portion having a unit of several tens of μm.

[0031]

According to the present invention, a laminate in which an organic layer having at least a light emitting layer is sandwiched between a non-translucent back electrode and a translucent front electrode is provided on a translucent support substrate. Naru Organic E
With respect to the L panel, by providing a slit in the back electrode, it is possible to suppress the occurrence of uneven brightness in the light emitting region of the display panel.

[Brief description of drawings]

FIG. 1 is a perspective view showing an organic EL panel according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a main part of the organic EL panel according to the first embodiment.

FIG. 3 is a diagram showing a formation state of back electrodes in the organic EL panel of the first embodiment.

FIG. 4 is a diagram showing a formation state of a back electrode in the organic EL panel of the second embodiment of the present invention.

[Explanation of symbols]

1 Organic EL panel 2 Glass substrate (support member) 3 Transparent electrode (front electrode) 3a Display segment part 3c electrode terminal 5 organic layers 6,11 Back electrode 6a, 11a electrode terminals 6b, 11b contact part 6c, 11c slit part 8 Organic EL element (laminate)

Claims (5)

[Claims] 1. An organic EL panel comprising a translucent support substrate and a laminated body in which an organic layer having at least a light emitting layer is sandwiched between a non-translucent back electrode and a translucent front electrode. The organic EL panel, wherein the back electrode is provided with a slit. 2. An organic EL panel comprising a translucent support substrate and a laminated body in which an organic layer having at least a light emitting layer is sandwiched between a non-translucent back electrode and a translucent front electrode. A back electrode formed as a common electrode, the front electrode formed so that the light emitting layer emits light in a predetermined manner by selectively applying a constant current, and a slit provided in the back electrode. An organic EL panel composed of and. 3. The slit is formed at least in the vicinity of a contact portion of the back electrode with the support substrate, or at least in the vicinity of a contact portion of the back electrode with an electrode terminal. The organic EL panel according to claim 1 or 2, which is characterized. 4. The organic EL panel according to claim 1, wherein the back electrode is composed of a metal electrode having a thickness of 150 nm or less. 5. The slit according to claim 1, wherein the slit provided in the back electrode is formed by any one of a vapor deposition method, laser processing, and an electrically insulating partition wall. The described organic EL panel.