JP3750631B2 - Manufacturing method of organic thin film light emitting element panel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing an organic thin film light-emitting element panel, and more particularly, a method of manufacturing an organic thin film light-emitting element panel capable of suppressing the increase in the connection resistance of the terminal portion even under high temperature and high humidity environment About.
[0002]
[Prior art]
Currently, as a flat panel display, a liquid crystal display (LCD), a plasma display (PDP), an electroluminescence display (ELD), and the like are known.
[0003]
These displays are provided with a plurality of linear conductive portions as external electrode portions at the end on a transparent substrate, and these external electrode portions are used for drive circuits such as flexible printed circuit boards (FPC) and tape carrier packages (TCP). The conductive portion is connected via an anisotropic conductive tape (ACF) or the like.
[0004]
In most of these displays, the connection portion between the substrate and the conductive portion for the drive circuit is processed at a pitch of 100 μm or less, and the connection between the external electrode portion and the FPC or TCP is made in a region narrower than this pitch. Since it is necessary, the connection is made in an extremely small area. In addition, there is a tendency that a wire having a small surface roughness is required for a linear conductive portion of a recent organic EL display. Along with this, the surface roughness of the external electrode portion at the end is also reduced.
[0005]
[Problems to be solved by the invention]
However, if the ACF terminal connection is made to such an external electrode part having a small surface roughness, the resistance of the terminal connection part increases in environmental tests such as a storage test and a heat cycle test in a high temperature / high humidity environment. Therefore, there is a problem that the power consumption increases and the risk of the connection portion being destroyed increases.
[0006]
The present invention, this in view of the problems has been made, it is an object of manufacturing an organic thin film light-emitting element panel capable of suppressing the increase in the connection resistance of the terminal portion even under high temperature and high humidity environment It is to provide a method.
[0007]
[Means for Solving the Problems]
In order to solve this problem, the present invention provides a method for manufacturing an organic thin film light emitting element panel, comprising: forming an organic thin film light emitting element part on a substrate;
Providing a rough surface on the substrate surface other than the region where the organic thin film light emitting element is formed,
It characterized Rukoto a step of forming a linear conductive portion of the external electrode at a desired position on the roughened substrate surface.
[0008]
The invention according to claim 2 further includes a step of connecting the linear conductive portion and the anisotropic conductive tape after the step of forming the linear conductive portion in the invention according to claim 1. It is characterized by that.
Furthermore, the invention described in claim 3 is the method of manufacturing an organic thin film light emitting element panel according to claim 1 or 2, wherein the step of providing irregularities on the substrate to roughen the substrate is performed by wet etching or dry etching. It is characterized by that.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0013]
FIG. 1 is a view for explaining a state in the vicinity of an end portion of an organic thin film light emitting element panel according to the present invention, in which an organic EL light emitting element 2 is provided via an external electrode portion 3 formed on a substrate 1. The external electrode unit 3 is electrically connected to a drive circuit (not shown) to drive the organic EL light emitting element 2.
[0014]
The region of the substrate 1 on which the external electrode part 3 is formed is processed in advance so as to have an appropriate surface roughness, and the external electrode part 3 is formed thereon to reflect the surface state of the end of the substrate 1. Thus, the surface of the external electrode portion 3 is moderately roughened. According to the study by the present inventors, it is concluded that the above-mentioned problem of the conventional organic thin film light emitting element panel is caused by the fact that the surface area of the external electrode portion is smooth and the connection area with the drive circuit is reduced. It is done. For this reason, in the organic thin-film light-emitting element panel of the present invention, it is possible to suppress an increase in connection resistance by increasing the contact area with the conductive particles in the ACF by providing an appropriate roughness on the surface of the external electrode portion. It is possible.
[0015]
The degree of surface roughness of the external electrode portion is such that the average surface roughness (Ra) of any linear conductive portion constituting the external electrode portion is preferably 1 nm or more, and the maximum difference in surface roughness (Rmax) ) Is preferably 10 nm or more.
[0016]
In the above description, the external electrode portion 3 is formed after the region of the substrate 1 on which the external electrode portion 3 is to be formed is previously processed to have an appropriate surface roughness. However, the present invention is not limited to this. The same effect can be obtained by forming the external electrode portion 3 without processing the substrate 1 and then roughening at least the external electrode portion 3 by a technique such as etching or sputtering. .
[0017]
[Example 1]
FIG. 2 is a view for explaining a procedure for manufacturing the organic thin film light emitting element panel of the present invention described in FIG. 1. In this example, the surface of the linear conductive portion constituting the external electrode portion by wet etching is illustrated. I am going to wreck.
[0018]
First, a substrate 21 on which an organic thin film light emitting element is formed is prepared (FIG. 2A), and a resist 22 for protecting an organic film forming portion on the substrate 21 is applied (FIG. 2B). Further, when the emitted light is extracted from the substrate 21, a resist is also applied to the back surface of the organic film deposition portion to protect it.
[0019]
After the resist is dried, etching is performed by immersing the substrate 21 in an etchant 23 that can be etched (FIG. 2C). Since the resist 22 is not applied to the region of the substrate 21 where the external electrode portion is to be formed, the surface of the substrate 21 in this region is roughened by this etching.
[0020]
After the desired surface roughness is obtained, the substrate 21 is taken out from the etching solution 23, washed with pure water, and immersed in the stripping solution 24 to strip the resist 22 (FIG. 2D).
[0021]
Finally, after washing with IPA and pure water, the linear conductive portion 25 and an electrode (not shown) are formed by sputtering (FIG. 2E). Of the linear conductive portion 25, the portion formed on the substrate 21 that is not covered with the resist 22 has an appropriate surface roughness reflecting the roughness of the surface of the substrate 21, and this portion serves as the external electrode portion. Will be configured.
[0022]
In this method, since the surface roughness of the external electrode portion depends on the etching time, it is necessary to obtain the etching time dependency of the surface roughness in advance.
[0023]
FIG. 3 and FIG. 4 are diagrams for explaining the results of obtaining the etching time dependence of the average surface roughness (Ra) and the maximum height difference (Rmax) of the external electrode part, respectively, as the etching time increases. Ra and Rmax gradually increase. In this case, the etching time when Ra is 1 nm or more is about 25 seconds, and the etching time when Rmax is 10 nm or more is about 30 seconds.
[0024]
[Example 2]
FIG. 5 is a view for explaining another procedure for manufacturing the organic thin film light emitting element panel of the present invention described in FIG. 1. In this example, the surface of the external electrode portion is roughened by dry etching.
[0025]
First, a substrate 51 on which an organic thin film light emitting element portion is formed is prepared (FIG. 5A), and a resist 52 for protecting the organic film forming portion on the substrate 51 is applied (FIG. 5B).
[0026]
After the resist 52 is dried, the substrate 51 is placed in a vacuum vessel 53 that can be dry-etched to perform etching (FIG. 5C). Since the resist 52 is not applied to the region of the substrate 51 where the external electrode portion is to be formed, the surface of the substrate 51 in this region is roughened by this etching.
[0027]
When the desired surface roughness is obtained, the substrate 51 is taken out from the vacuum vessel 53 and washed with pure water, and then immersed in a stripping solution 54 to strip the resist 52 (FIG. 5D).
[0028]
Finally, after washing with IPA and pure water, the linear conductor 55 and an electrode (not shown) are formed by sputtering (FIG. 5E). Of the linear conductive portion 55, a portion formed on the substrate 51 that is not covered with the resist 52 has an appropriate surface roughness reflecting the surface roughness of the substrate 51, and this portion is used as an external electrode. It is done.
[0029]
In the first and second embodiments, the processing for roughening the surface of the external electrode portion has been described as being performed before the film formation of the linear conductive portion. However, the present invention is not limited to this, and the surface state of the substrate The linear conductive portion may be formed without roughening the surface, and then the surface of the external electrode portion may be roughened.
[0030]
[Comparative Example]
Below, the result of having compared the change of connection resistance on the high temperature and high humidity conditions of the organic thin film light emitting element panel produced by the method mentioned above and the organic thin film light emitting element panel produced by the conventional method is demonstrated.
[0031]
The organic thin film light-emitting element panel of the present invention, the end of the glass substrate of 50 mm × 50 mm was formed and the organic thin film light-emitting layer by wet etching with an average surface roughness 3 nm, the surface condition of the height difference 30 nm, this In ₂ A 200 nm pattern film was formed using O ₃ —ZnO as a conductive material for the linear conductive portion.
[0032]
On the other hand, in an organic thin film light emitting element panel having a conventional configuration, a 200 nm pattern was formed using In ₂ O ₃ —ZnO as a conductive material on a 50 mm × 50 mm glass substrate on which an organic thin film light emitting layer was formed. The average surface roughness of this glass substrate is 0.2 nm, and the height difference is 4 nm. The surface roughness of In ₂ O ₃ —ZnO, which is a linear conductive portion constituting the external electrode portion at the end, is also included. It has the same roughness.
[0033]
A test FPC was connected to the external electrode of the organic thin-film light-emitting element panel produced in this manner by ACF, and the change in connection resistance was examined under the conditions of high temperature and high humidity of 85 ° C. and 85% in this state.
[0034]
FIG. 6 is a diagram for explaining the state of change in connection resistance of these organic thin film light emitting element panels. In the organic thin film light emitting element panel having a conventional configuration, the resistance value, which was an initial value of 5Ω, suddenly increases with time. While the connection resistance increases and is saturated at about 30Ω after about 100 hours, the organic thin-film light-emitting element panel of the present invention maintains the initial value of 5Ω even after 500 hours has elapsed, so that stable connection is achieved. Resistance is obtained.
[0035]
【The invention's effect】
As described above, according to the present invention, the contact area with the conductive particles in the ACF is increased by providing an appropriate roughness on the surface of the linear conductive portion constituting the external electrode portion. -It becomes possible to provide the manufacturing method of the organic thin film light emitting element panel which can suppress the increase in the connection resistance of a terminal part also in a high humidity environment.
[Brief description of the drawings]
FIG. 1 is a view for explaining a state in the vicinity of an external electrode portion provided at an end of an organic thin film light emitting element panel of the present invention.
FIG. 2 is a diagram for explaining a procedure for manufacturing the organic thin film light emitting element panel of the present invention when the surface of the linear conductive portion is roughened by wet etching.
FIG. 3 is a diagram for explaining a result of obtaining an etching time dependency of an average surface roughness of a linear conductive portion constituting an external electrode portion.
FIG. 4 is a diagram for explaining the result of obtaining the etching time dependence of the maximum height difference (Rmax).
FIG. 5 is a diagram for explaining a procedure for manufacturing the organic thin film light emitting element panel of the present invention when the surface of the linear conductive portion is roughened by dry etching.
FIG. 6 is a diagram for explaining the change in connection resistance between the organic thin-film light-emitting element panel of the present invention and the organic thin-film light-emitting element panel of the conventional configuration under high temperature and high humidity conditions of 85 ° C. and 85%. is there.
[Explanation of symbols]
1, 2, 51 Substrate 2 Organic EL light emitting element 3 External electrode part 22, 52 Resist 23 Etching liquid 24, 54 Stripping liquid 25, 55 Linear conductive part 53 Vacuum container

Claims (3)

Forming an organic thin film light emitting element on a substrate;
Providing a rough surface on the substrate surface other than the region where the organic thin film light emitting element is formed,
And a step of forming a linear conductive portion for an external electrode at a desired position on the roughened substrate surface. 2. The method of manufacturing an organic thin film light emitting element panel according to claim 1 , further comprising a step of connecting the linear conductive portion and the anisotropic conductive tape after the step of forming the linear conductive portion. Wherein the step of roughening by irregularities on the substrate surface, method of manufacturing an organic thin film light-emitting element panel according to claim 1 or claim 2, characterized in that is carried out by wet etching or dry etching.

Images