Organic led element of dot matrix type

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention is also referred to as injection-type electroluminescence (EL), and relates to an organic LED element that emits light by injecting electrons and holes into an organic thin-film EL material and recombining them. It relates to an organic LED element having an electrode arrangement that can be driven in a dot matrix shape in order to have a display function.

【0002】

[Conventional technology]

Examples of the configuration of the conventional dot matrix type organic LED element 90 are shown in FIGS. 4 and 5, and the hotoriso method or screen printing is performed on the transparent substrate 91 formed of a transparent member such as glass or resin. A plurality of anode electrodes 92 made of transparent conductive members such as ITO are formed in parallel by a method or the like.

【0003】

A luminescent organic layer 93 is formed on the surface of the transparent substrate 91 on the side where the anode electrode 92 is laid by a screen printing method or the like, and the upper surface of the luminescent organic layer 93 has a small work function. A plurality of cathode electrodes 94 made of a metal, for example, a mixture of Mg: Ag, are laid in parallel in a direction orthogonal to the anode electrodes 92.

【0004】

Here, the luminescent organic layer 93 is not necessarily a single layer, and is a layer having an appropriate function from each of the hole injection layer, the hole transport layer, the light emitting layer, and the electron injection layer, each of which is formed of an organic material. Is selected and is configured as a layer including at least a light emitting layer.

【0005】

[Problems to be Solved by the Invention]

However, in the dot matrix type organic LED element 90 having the above-mentioned conventional configuration, if the anode electrode 92 has an excessively high resistance, the voltage drop in the anode electrode 92 is remarkable, and the efficiency is lowered as a whole. Therefore, it is generally formed as a film thickness of 2000 Å.

【0006】

On the other hand, the luminescent organic layer 93 generally has a film thickness of about 1000 Å. Therefore, as is clear from the cross-sectional view shown in FIG. 5, the luminescent organic layer 93 is the luminescent organic layer 93 itself. The cathode electrode 94 is also laid on the uneven surface, which exceeds the film thickness of the above.

【0007】

At this time, if, as shown in FIG. 6, a portion where the film is not formed is formed on the side of the luminescent organic layer 93 due to the unevenness of the surface described above, the anode electrode 92 and the cathode electrode 94 are formed. If they come into contact with each other and cause a short-circuit accident, and if a portion where film formation is not performed occurs on the side of the cathode electrode 94 as shown in FIG. 7, a disconnection accident occurs in the cathode electrode 94. In any case, the dot matrix type organic LED element 90 becomes a defective product, which causes a problem of impairing productivity such as a decrease in yield, and a solution to this problem has been an issue.

【0008】

[Means for solving problems]

In the present invention, as a specific means for solving the above-mentioned conventional problems, a luminescent organic layer is formed on a transparent substrate in which a plurality of anode electrodes are laid in parallel in either one of rows and columns. Further, in a dot matrix type organic LED element in which a plurality of cathode electrodes are laid in parallel on the luminescent organic layer in a direction orthogonal to the positive electrode, between each of the anode electrodes and the anode electrode. An insulating film having a film thickness of [(absolute value of (thickness of anode electrode-thickness of insulating film)] <(thickness of luminescent organic layer) is provided at the outer end in the longitudinal direction. The problem is solved by providing a dot matrix type organic LED element characterized by the above.

【0009】

BEST MODE FOR CARRYING OUT THE INVENTION

Next, the present invention will be described in detail based on one embodiment shown in the figure. What is indicated by reference numeral 1 in FIGS. 1 and 2 is a dot matrix type organic LED element (hereinafter abbreviated as organic LED element 1) according to the present invention, and the organic LED element 1 is a transparent member such as glass or resin. On the transparent substrate 2 formed of the above, a plurality of anode electrodes 3 by ITO or the like are laid in parallel in either one of the rows and columns, which is the same as that of the conventional example.

【0010】

Further, a luminescent organic layer 4 is formed on the anode electrode 3, and a plurality of cathode electrodes 5 are formed on the upper surface of the luminescent organic layer 4 in a direction orthogonal to the anode electrode 3. However, according to the present invention, an insulating film 6 is formed between the anode electrodes 3 and the outermost end of the outermost anode electrode 3 in the longitudinal direction. Is supposed to be provided.

【0011】

Here, in forming the insulating film 6, it is necessary to lay it accurately between the anode electrodes 3 and in a relatively narrow place, so it is preferable to form the film by the hotoriso method or the like. Therefore, the hotoriso Possible SiO₂Alternatively, a photosensitive resin such as ultraviolet curable is adopted as a member of the insulating film 6. If the distance between the anode electrodes 3 is as wide as 0.1 mm or more, it can be formed by the mask vapor deposition method. In this case, the insulating film 6 can be selected from a wider range. It becomes.

【0012】

Further, in the present invention, the film thickness t3 of the insulating film 6 is also limited, and the film thickness t3 of the insulating film 6 is determined by the film thickness t1 of the anode electrode and the film thickness t2 of the luminescent organic layer 4. It is formed so as to satisfy the condition of [(absolute value of (film thickness t1-film thickness t3 of anode electrode)] <(film thickness t2 of luminescent organic layer).

【0013】

Assuming that the film thickness t1 of the anode electrode 3 is 2000 Å and the film thickness t2 of the luminescent organic layer 4 is 1000 Å under the above conditions, more specifically, the film thickness of the anode electrode 3 will be described. The absolute value obtained by subtracting the film thickness t3 of the insulating film 6 from t1 (that is, 2000 Å) does not exceed the film thickness t2 (that is, 1000 Å) of the luminescent organic layer 4, that is, the above conditions. Then, the film thickness t3 of the insulating film 6 is 1000 Å or more and 3000 Å or less.

【0014】

In actual implementation, a sufficient margin is expected in consideration of manufacturing variations of the anode electrode 3 and the luminescent organic layer 4, and the film thickness t3 of the insulating film 6 is set to 1500 Å or more, 2500 Å or less, and the like. Further, as will be described later, for example, 1800 Å or more and 2200 Å or less, the smaller the difference from the anode electrode 3, the more preferable the result can be obtained.

【0015】

Next, the operation and effect of the present invention having the above configuration will be described. The light emitting organic layer 4 has a step between the surface of the transparent substrate 2 and the upper surface of the anode electrode 3 between the anode electrodes 3 having the film thickness t1. By providing the insulating film 6 having a film thickness t3 that is smaller than the film thickness t2, in the organic LED element 1 of the present invention, the luminescent organic layer 4 laid on the upper surface of the anode electrode 3 has a film thickness t2 or less. It will be laid on the uneven surface.

【0016】

Therefore, even when the film thickness t3 of the insulating film 6 is thinner than the film thickness t1 of the anode electrode 3 as shown in FIG. 2, or as shown in FIG. 3, the insulating film 6 is thinner than the film thickness t1 of the anode electrode 3. Even when the film thickness t3 is thick, the luminescent organic layer 4 does not have a portion where the film thickness is interrupted due to the above-mentioned unevenness and the film is not formed. Short circuit accidents can be completely prevented.

【0017】

Further, the fact that the step on the uneven surface is reduced by the insulating film 6 means that the film surface is not interrupted with respect to the luminescent organic layer 4 as described above, and a film is formed on the upper surface of the luminescent organic layer 4. The unevenness of the cathode electrode 5 is also reduced, so that the cathode electrode 5 does not have a break in the film surface, and a disconnection accident of the cathode electrode 5 can be prevented.

【0018】

[Effect of the invention]

As described above, according to the present invention, the film thickness is set to [(anode electrode film thickness-insulation film film thickness) between each of the anode electrodes and the end portion on the outer side in the longitudinal direction of the anode electrode. Absolute value of] <(Thickness of luminescent organic layer) The transparent substrate and anode electrode generated on the laying surface of the luminescent organic layer by using a dot matrix type organic LED element provided with an insulating film. The step that exceeds the film thickness of the luminescent organic layer is relaxed within the range of the film thickness of the luminescent organic layer by the insulating film, which causes a break in the film surface of the luminescent organic layer, and the anode electrode and the cathode. This is to prevent a short circuit accident with the electrode or a breakage of the film surface on the cathode electrode to cause a disconnection accident, thereby improving the retention of this type of dot matrix type organic LED element. It has an extremely excellent effect on improving productivity.

[Simple explanation of drawings]

[Figure 1]

It is a top view which shows one Embodiment of the dot matrix type organic LED element which concerns on this invention.

[Figure 2]

It is sectional drawing which follows the AA line of FIG.

[Fig. 3]

It is sectional drawing which shows the other embodiment of the dot matrix type organic LED element which also concerns on this invention in the main part.

[Fig. 4]

It is a top view which shows the conventional example.

[Fig. 5]

It is sectional drawing which follows the line BB of FIG.

[Fig. 6]

It is explanatory drawing which shows the example of the short circuit accident which occurs in the conventional example.

[Fig. 7]

It is explanatory drawing which shows the example of the disconnection accident which occurs in the conventional example.

[Explanation of symbols]

1 ...... Dot matrix type organic LED element 2 ...... Transparent substrate 3 ...... Anode electrode 4 ...... Luminous organic layer 5 ...... Cathode electrode 6 ...... Insulation film t1 ...... Anode electrode film thickness t2 ...... Film thickness of luminescent organic layer t3 ...... Insulating film thickness