JP2000068053A - Manufacture of organic luminescent device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispense with the positioning of a metal mask and provide a large and precise organic luminescent device by determining the width ratio of a part corresponding to a light emitting part and the boundary part of a luminescent pixel above a specific range relative to an evaporation mask used, when the pixels of the luminescent element are distinguished or when a multicolored luminescent pixel is manufactured. SOLUTION: The line width of a metal mask for determining a pixel boundary of a cathode electrode for determing the pixel of a luminescent element is taken large. That is, the ratio of the width of a part corresponding particularly to a light generating part (an exposed part of a mask) and a boundary part of a luminescent pixel (a metal part of the mask) is set so as to be above 1:0.5 in a deposition mask. In a metal mask 2, for example, the ratio of an exposed part on which the cathode electrode is to be deposited and a meal part 22 as a mask part is determined to be 1:2, a base is moved by one pixel after the first deposition, and then the base is moved once more to realize the luminescent pixel of RGB. As a result, the positioning of the metal mask 2 becomes unnecessary.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic light-emitting display device, and more particularly to a structure of a high-definition display and a method and apparatus for manufacturing the same.

[0002]

2. Description of the Related Art When an organic light-emitting device is used to manufacture a display aiming at enlargement or high definition,
It is necessary to make each pixel emit light separately. In order to divide each pixel, a portion where a vertical electrode and a horizontal electrode intersect usually serves as a light emitting point, and it is general to provide a plurality of the pixels to enlarge the screen.

In an organic light emitting display, a transparent electrode is formed as an elongated line on a glass substrate to secure an electrode portion in one direction. In the other direction, in the lateral direction, the metal mask used for manufacturing the cathode electrode of the organic light emitting element is formed in such a manner that a vapor deposition portion is left out, and the cathode electrode is vapor-deposited in the left portion.

When the function of the organic light emitting display is advanced one step, for example, when a high definition, a large area, and a color are performed, a method of manufacturing an organic light emitting display using a simple metal mask cannot be used.

As an example, when a display of a 0.3 mm square light emitting pixel is considered, a metal mask used for manufacturing the display needs to have a hole having a hole corresponding to 0.3 mm of a light emitting portion.

Further, a metal line of a mask for preventing adhesion of a cathode electrode on a portion for separating pixels, that is, a mask metal line for preventing the adhesion of a cathode electrode (this separation width is required to be as small as possible in order to increase the opening area of a light emitting region. (If one sixth of the area is set to 0.05 mm), a large number of lines are arranged.

A metal mask in which a plurality of lines of 0.05 mm are arranged in parallel with a plurality of lines of 0.3 mm has a limit in a length direction of 100 to 200 times the line width in order to function stably. The emission width of an organic light-emitting display using a metal mask (of course, other directions do not apply to this discussion) is limited to at most 20 mm.

[0008]

SUMMARY OF THE INVENTION The present invention solves the problem of increasing the size and increasing the definition by changing the structure of a metal mask and its use in the production of a conventional organic light emitting display.

The reason why the conventional metal mask cannot be enlarged is described again. As shown in the conventional example, when the ratio between the line width and the length of the metal mask exceeds a certain range, the geometric stability is limited. Is caused.

One of the limiting factors is due to the expansion of the metal mask due to temperature, and the other is due to insufficient mechanical rigidity, and is caused by slight vibration and stress (including the relaxation of internal stress). This is because the position of the line of the mask is displaced, so that the geometrical position is not secured.

The second problem is that, in the case of a single color, the number of simple light-emitting pixels in the light-emitting area of the display is simply increased, and the metal mask work is performed only once. When performing this, it is necessary to ensure the positional relationship between the positions of the light emitting pixels of each color and the metal mask. The problem is how to secure the positioning accuracy.

[0012] Of course, the above-mentioned problems are not problems that cannot be overcome by the current technology, but alignment with micron precision in a vacuum device is not a simple technology.

In order to overcome the above-mentioned drawbacks, the present invention mainly involves increasing the rigidity of the metal mask and eliminating alignment of the metal mask (extremely loose positioning accuracy). Is a point.

[0014]

SUMMARY OF THE INVENTION The present invention is used for manufacturing an organic light emitting device display comprising a plurality of organic light emitting devices arranged side by side when dividing light emitting device pixels or manufacturing multicolor light emitting pixels. The vapor deposition mask is characterized in that the ratio of the width of the portion corresponding to the light emitting portion (the open portion in the mask) and the width of the boundary portion between the light emitting pixels (the metal portion in the mask) is 1: 0.5 or more.

[0015]

The means taken to increase the rigidity of the metal mask is to increase the line width of the metal mask which determines the pixel boundary of the cathode electrode which determines the pixel of the light emitting element.

With the light emitting area of 0.3 mm width shown in the conventional example,
For example, a structure having a line width of 0.05 mm for determining a boundary has the same light emitting area as 0.3 mm as an example.

If the line width of the metal mask for determining the boundary area is compared with this configuration, it is expected that the rigidity will be increased by a factor of six even in a simple calculation by increasing the line width from 0.05 mm to 0.3 mm.

Of course, since the thickness of the substrate can be increased, the rigidity of the present embodiment can be increased by one digit or more. Of course, by further increasing the line width region, a further increase in rigidity can be obtained.

Next, the prevention of deformation due to thermal expansion can be mentioned. However, when the evaporation material is heated during vapor deposition, the temperature of the metal mask rises. If the temperature does not expand due to a rise in the temperature of the mask, or if it is small, the amount of deformation is small.

The present invention aims at reducing the expansion coefficient of the mask material to a negative value and conversely contracting it when the temperature rises. To increase the number.

In order to further increase the effect, it is also possible to increase the effect by providing an outer frame of a metal mask and actively applying stress to the outer frame using a material having a larger expansion coefficient than the mask. is there.

The reason why the line width at the boundary of the metal mask can be made large can be attained by dividing the vapor deposition operation.

The vapor deposition operation is described in detail. The first vapor deposition is performed by a conventional method, and then the metal mask or the substrate is moved by one pixel (not particularly limited to one pixel), and the second vapor deposition is performed. Is deposited.

Here, the first vapor deposition and the second vapor deposition are completely the same operation. The result is that the first and second patterns are deposited on the substrate in parallel.

Conventionally, 0.3 mm (open portion), 0.05
A similar vapor deposition pattern can be realized by moving a 0.3 mm (open portion) pattern by 0.35 mm in the metal mask of the present invention from a line of mm (metal portion), 0.3 mm, and 0.05 mm. Can be done. At that time, the skipped portion must have the metal mask not opened.

In particular, when colorization is performed, RGB and light-emitting pixels are arranged side by side, but a red organic light-emitting material is vapor-deposited at the R portion in the first vapor deposition, and a metal mask is vapor-deposited at the same time.

Next, in the second deposition, the mask or the substrate is moved by one pixel to deposit G, that is, a green organic material and a metal mask.

Further, a third B, ie, blue deposition is performed. In this vapor deposition work, the organic material of each color and the cathode electrode at that position can be formed at the same time, so there is no particular need to position the metal mask, and it is only necessary to move one pixel. There is no.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an element configuration of the organic light emitting display device of the present invention.

In FIG. 1, reference numeral 11 denotes a display substrate, and reference numeral 12 denotes a transparent electrode provided on a glass substrate.
13 is a hole transport material, 14 is an electron transport material, and 15 is a cathode electrode.

One embodiment of the production of the organic light emitting device is as follows.
A transparent electrode on a glass substrate is formed by photolithography, and a hole transport material 13 and an electron transport material 14 are deposited on the entire surface of the substrate. Further, the cathode electrode 15 is prepared by preparing a metal mask corresponding to the electrode shape and performing a vapor deposition operation in a vacuum device.

FIG. 2 shows an embodiment of the metal mask of the present invention. In FIG. 2, reference numeral 21 denotes an open portion of a mask on which a cathode electrode is deposited, and reference numeral 22 denotes a metal portion serving as a shielding portion. In FIG. 2, the ratio between the open portion 21 and the metal portion 22 is set to 1: 2 for the purpose of providing RGB three-color pixels.

FIG. 3 shows an example of the structure of a vapor deposition apparatus. In the figure, 1
Denotes an evaporation source, 2 denotes a metal mask, and 3 denotes a substrate. In this embodiment, the substrate 3 is moved by one pixel after the first vapor deposition, and the substrate is moved again to realize RGB light emitting pixels.

In the present invention, RGB and RGB can be repeated at one time in the present invention, so that the first position and the third position do not have to overlap each other. 0.05 mm, the positioning accuracy when the metal mask is moved 0.6 mm is 0.05 mm
It must be:

The relative accuracy of the movement distance and the positioning accuracy accompanying the movement is 0.05 / 0.3 = 0.16, which is 10%.
It can be seen that the following feeding accuracy should be ensured.

It is preferable that the ratio of the width of the portion corresponding to the light emitting portion (open portion in the mask) and the width of the boundary portion between the light emitting pixels (metal portion in the mask) be 1 to 2 in particular.

Further, when the metal mask is used, the metal mask may be pulled from the periphery of the metal mask with a spring to ensure flatness.

[0038]

As described above, according to the present invention, a fine pattern pixel can be realized and a full-color display can be produced without mask alignment by only slightly changing the pattern configuration and the vapor deposition operation of the metal mask. Large size and high definition can be easily achieved.

In particular, the fact that the positioning technology corresponding to the micron accuracy has been made possible without performing the positioning with a micron accuracy in a vacuum apparatus has a great effect in terms of promoting the spread of the technology. There is something.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an organic light emitting device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a metal mask structure according to the embodiment;

FIG. 3 is a schematic view of an apparatus for manufacturing an organic light emitting device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Deposition source 2 Metal mask 3 Substrate 11 Display substrate 12 ITO transparent electrode 13 Hole transport material 14 Electron transport material 15 Cathode electrode 21 Open part 22 Metal part

Continued on the front page F term (reference) 3K007 AB04 AB06 AB17 AB18 BA06 CB01 DA01 DB03 EB00 FA01 4K029 AA09 BB03 BD00 HA05 5C094 AA05 AA14 AA43 AA46 AA48 BA12 BA27 CA19 DA13 DB01 EA05 FA01 FB03 FB12 GB10 JA08

Claims (7)

[Claims] 1. An organic light-emitting element display comprising a plurality of organic light-emitting elements arranged, a deposition mask used for dividing light-emitting element pixels or for producing multicolor light-emitting pixels corresponds to a light-emitting portion. A method of manufacturing an organic light-emitting device, wherein a ratio of a width of a portion to be formed (a portion opened by a mask) to a boundary portion of a light-emitting pixel (a metal portion in a mask) is set to 1: 0.5 or more. 2. The method according to claim 1, wherein a ratio of a width of a portion corresponding to a light emitting portion (open portion in the mask) and a width of a boundary portion of the light emitting pixel (metal portion in the mask) is 1: 2. The method for manufacturing an organic light emitting device according to claim 1. 3. A method of manufacturing an organic light-emitting device display comprising a plurality of organic light-emitting devices, wherein a metal mask used for dividing light-emitting device pixels or for manufacturing multicolor light-emitting pixels is formed by the same operation. 3. The method for manufacturing an organic light emitting device according to claim 1, wherein the method is used when manufacturing an organic light emitting material and when manufacturing a cathode electrode. 4. The method for manufacturing an organic light emitting device according to claim 1, wherein a material having a negative thermal expansion coefficient is used as a material of the metal mask. 5. The method for manufacturing an organic light-emitting device according to claim 1, wherein when the metal mask is used, the flatness is secured by pulling the metal mask from the periphery thereof with a spring. 6. The method for manufacturing an organic light emitting device according to claim 1, wherein a material having a coefficient of thermal expansion larger than that of the metal mask is used as a frame around the metal mask. 7. An apparatus for manufacturing an organic light-emitting device using the metal mask according to claim 1.