JP4089228B2 - Display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a display device in which a plurality of light emitting elements are arranged in a matrix, a manufacturing method thereof, and a vapor deposition mask used in the display method.
[0002]
[Prior art]
An organic EL element (organic EL element) using electroluminescence of organic material (hereinafter referred to as EL) has an organic layer sandwiched between an anode and a cathode. In the organic EL element having such a configuration, light generated when holes injected from the anode and electrons injected from the cathode recombine in the organic layer is extracted as emitted light from the cathode or anode side, It attracts attention as a light emitting element capable of emitting light with high brightness of several hundreds to several 10000 cd / m ² at a low driving voltage of 10 V or less. In addition, in the organic EL element, it is possible to obtain light emitting elements that emit light of each color by selecting the material of the organic layer. By arranging the light emitting elements that emit light of each color in a predetermined state, multicolor display or full color display is achieved. Can be configured.
[0003]
In the case of manufacturing a display device including an organic EL element having such a configuration, first, a lower electrode serving as a cathode (or an anode) is patterned on a substrate, and then an organic layer is formed on the lower electrode. . The formation of the organic layer is usually performed by a vacuum deposition method. In addition, after the organic layer is formed, an upper electrode serving as an anode (or a cathode) is formed in a state in which insulation with the lower electrode is ensured.
[0004]
In particular, in a display device capable of color display, for example, a display device that performs full-color display, a display element that emits light of each color of R (red), G (green), and B (blue) is provided for each pixel (subpixel). One picture element (pixel) is composed of three adjacent R, G, and B pixels. In manufacturing such a display device, it is necessary to form a light emitting element that emits light of each color for each pixel. Therefore, for example, in the organic layer pattern forming step, as shown in FIG. 5, the organic layer patterns 3 r and 3 g of the respective emission colors are provided for each specific pixel 2 among the pixels 2 arranged on the substrate 1. , 3b are formed separately.
[0005]
Such organic layer patterns 3r, 3g, and 3b are formed by a vapor deposition method using a vapor deposition mask as shown in FIG. 6, for example. The vapor deposition mask 5 is disposed opposite to the surface of the substrate 1 where the pixels 2 are disposed, and only the pixel (for example, red) 2r in which light emitting elements that emit light of a specific color among the plurality of pixels 2 are disposed. Is provided with an opening 5r for exposing the.
[0006]
Further, the vacuum deposition using the deposition mask 5 is performed in a state where the deposition material is evaporated from the deposition source on one surface side of the deposition mask 5 and the substrate 1 is disposed on the other surface side of the deposition mask 5.
[0007]
As an example of such a vapor deposition method, Japanese Patent Application Laid-Open No. 2001-93667 discloses a production apparatus and a production method for moving a substrate and a vapor deposition mask with respect to a vapor deposition source. In this method, as shown in the schematic diagram of FIG. 7, a deposition source 12 is disposed below an opening 11 a provided in the shielding plate 11 for partitioning the deposition space, and the deposition mask 5 is disposed above the shielding plate 11. And the substrate 1 disposed on the upper part of the substrate 11 are relatively deposited with respect to the opening 11a and the deposition source 12, and the deposition is performed. In this method, the opening 11a and the vapor deposition source 12 are provided in a linear shape having a width equal to or larger than the width of the vapor deposition region in a direction orthogonal to the moving direction of the substrate 1 and the vapor deposition mask 3 (the direction indicated by the arrow in the figure). It has been.
[0008]
[Problems to be solved by the invention]
Here, FIG. 8 shows a view of FIG. 7 as seen from the traveling direction of the substrate 1 and the vapor deposition mask 5. As shown in FIG. 8, with respect to a direction perpendicular to the moving direction of the substrate 1 and the vapor deposition mask 5 (hereinafter referred to as vapor deposition width direction), the vapor deposition source 12 has a width equal to or larger than the vapor deposition region in the substrate 1. The opening (11a) of the shielding plate (11) (not shown) has a shape corresponding to the vapor deposition source 12. For this reason, the vapor deposition component a scattered in the vapor deposition width direction (the extending direction of the vapor deposition source 12) from the vapor deposition source 12 reaches the substrate 1 through the vapor deposition mask 3 without being cut by the shielding plate.
[0009]
Therefore, in the vapor deposition method as described above, among the vapor deposition component a scattered in the vapor deposition width direction from the vapor deposition source 12, the vapor deposition component (oblique vapor deposition component) a1 supplied from the oblique direction to the substrate 1 is also used as the vapor deposition mask 5. Since it is supplied to the substrate 1 from an oblique direction with respect to the opening, it is possible to make the film thickness of the organic layer pattern 5r (5gor5b) deposited on the substrate 1 through the deposition mask 3 uniform in the deposition width direction. Can not. FIG. 9 shows the relative film thickness ratio of the organic layer pattern 5r in the vapor deposition width direction. As shown in this figure, the relative film thickness ratio of the organic layer pattern formed in the central part of the substrate is maintained at a constant film thickness in the central part, but the oblique vapor deposition component at the end part in the vapor deposition width direction. Since the film is formed by supplying only a1, the film thickness is reduced. For the same reason, for example, the relative film thickness ratio of the organic layer pattern formed on the left end portion of the substrate is thin because the left end portion is formed only by the intrusion of oblique deposition components from the right side. It becomes.
[0010]
By the way, in a light emitting device in which an organic layer pattern is sandwiched between electrodes, the film thickness of the organic layer pattern greatly affects the light emitting characteristics of the device. For this reason, in order to ensure the light emission characteristic in each light emitting element, it is necessary to use only the part with the uniform film thickness of an organic layer pattern as a light emitting element. For this reason, the decrease (variation) in the relative film thickness ratio at the end of the organic layer pattern as described above becomes a factor that decreases the aperture ratio of each pixel, and improves the luminance of the display device, thereby increasing the integration density. This is a factor preventing high resolution.
[0011]
Therefore, the present invention relates to a display device in which a plurality of pixels provided with a light emitting element having a light emitting material layer sandwiched between electrode material layers are arranged on a substrate, and the luminance can be improved by improving the pixel aperture ratio. The present invention relates to a display device and a method for manufacturing the display device, and a method for manufacturing a display device capable of forming a vapor deposition pattern of a material layer with a uniform film thickness, and a vapor deposition mask used in the method. For the purpose.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, a display device of the present invention is formed by arranging a plurality of pixels provided with a light-emitting element having a light-emitting material layer sandwiched between a lower electrode and an upper electrode on a substrate. Ri greens and, in an active matrix type display device used in common said upper electrode to said plurality of pixels comprises at least one of the deposition pattern of the material layers constituting the light-emitting element, these deposition pattern These are continuously provided so as to cover a plurality of pixels arranged adjacent to each other in one direction . Furthermore, the one-way interval between the pixels covered with each vapor deposition pattern is narrower than the one-way interval between the pixels covered with the vapor deposition pattern adjacent to the one direction among the vapor deposition patterns . An auxiliary electrode connected to the upper electrode is provided between the pixels covered with the vapor deposition pattern adjacent in the one direction .
[0013]
According to such a display device, than the spacing between the pixels covered with deposition patterns adjacent to one direction, by narrowing the spacing between the pixels arranged that in one direction in the same vapor-deposition pattern, each A pixel covered with the vapor deposition pattern is arranged at the center of the vapor deposition pattern. For this reason, compared with the case where all the some pixels are arrange | positioned at equal intervals, a some pixel can be arrange | positioned effectively using the center part of the vapor deposition pattern whose film thickness is stable. Therefore, the aperture ratio of the pixel can be improved. In addition, by providing auxiliary electrodes at wider intervals between the pixels, it is possible to prevent the auxiliary electrodes from affecting the arrangement of the pixels.
[0014]
The display device manufacturing method of the present invention is a method for manufacturing a display device in which a plurality of pixels each provided with a light emitting element having a light emitting material layer sandwiched between electrode material layers are arranged on a substrate. . In the present invention, a deposition source is disposed on one surface side of the deposition mask, the substrate is disposed on the other surface side of the deposition mask, and a plurality of arrays arranged in the first direction of the substrate from each opening of the deposition mask. With the pixels exposed in a lump, the deposition mask and the substrate are moved relative to the deposition source in a second direction orthogonal to the first direction. A vapor deposition pattern of the light emitting material layer is formed on each pixel .
[0015]
According to such a manufacturing method, since the plurality of pixels arranged in the first direction orthogonal to the moving direction (second direction) of the substrate and the deposition mask are exposed in a lump, this deposition is performed. The vapor deposition pattern formed by vapor deposition is provided in a continuous state across a plurality of pixels arranged in one direction on the substrate. Therefore, compared to the case of forming individual vapor deposition patterns corresponding to each pixel, the opening width of the vapor deposition mask in the first direction is widened, and the relative film thickness ratio variation of the vapor deposition pattern in the first direction of the substrate is different. Get smaller.
[0016]
In such a manufacturing method, by setting the width in the first direction of the vapor deposition source to be equal to or larger than the width of the vapor deposition region of the substrate, the vapor deposition components are scattered more uniformly in the first direction, and more uniform with respect to the substrate. The vapor deposition component can be incident on the substrate.
[0017]
Moreover, in such a manufacturing method, by providing a shielding plate having an opening at a position facing the vapor deposition source between the vapor deposition mask and the vapor deposition source, the vapor deposition mask side of the vapor deposition components scattered in the second direction. Only the vertical vapor deposition component can pass through the vapor deposition component. Therefore, the variation in the relative film thickness ratio of the vapor deposition pattern in the second direction of the substrate is reduced.
[0018]
The vapor deposition mask of the present invention is a vapor deposition mask used in the above-described manufacturing method, and is characterized in that it has an opening that collectively exposes a plurality of pixels arranged in one direction on the substrate.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be sequentially described in detail based on the drawings.
[0020]
<Display device>
FIG. 1 is a diagram showing an embodiment of a display device of the present invention, and FIG. 2 is a cross-sectional view taken along line AA ′ in FIG. The display device 101 shown in these drawings is a so-called stripe array display device in which a plurality of pixels 103 are arranged in a matrix on a substrate 102. In such a display device 101, since all the scanning lines and signal lines are orthogonal, the wiring layout is simple, and the display image is clear and the demand for a display device for a personal computer is high.
[0021]
Here, in each pixel 103, a lower electrode layer (not shown), organic layer patterns 104r, 104g, and 104b, and an upper electrode layer (not shown) are stacked in order from the substrate 101 side, and each stacked portion of these layers is stacked. The light emitting element which consists of is provided.
[0022]
Here, the organic layer patterns 104r, 104g, and 104b are vapor deposition patterns formed using a vapor deposition mask, and are formed of a material corresponding to the emission color of each light emitting element. Here, for example, the organic layer patterns 104r, 104g, and 104b corresponding to the emission colors of red (R), green (G), and blue (B) are arranged in the row direction (lateral direction in the drawing) p. It is provided so as to cover the two pixels 103 and 103. Further, the organic layer pattern 104r, the organic layer pattern 104g, and the organic layer pattern 104b are repeatedly arranged in the column direction (vertical direction in the drawing). One pixel is constituted by three pixels 103 arranged in the column direction.
[0023]
Here, each pixel 103 is gathered at the center in the row direction p of each organic layer pattern 104r, 104g, 104b, and the film thickness at the end in the row direction p in the organic layer pattern 104r, 104g, 104b is unstable. It is arrange | positioned inside the area | region d. The interval w1 between the pixels 103 covered with one organic layer pattern 104r, 104g, 104b is the interval between the pixels 103 covered with the organic layer pattern 104r (104g or 104b) adjacent in the row direction p. It is narrower than w2.
[0024]
In addition, the display device 101 is an active matrix system in which each light emitting element is driven by a thin film transistor, and an upper electrode (not shown) is formed so as to cover the entire region where the pixel 103 is arranged. In the case where it is used in common over the light emitting elements, an auxiliary electrode for preventing a voltage drop of the upper electrode is provided in a portion where the interval between the pixels 103 is wide (w2 portion).
[0025]
In the display device 101 having such a configuration, the same organic layer pattern 104r (104g) than the interval w2 between the pixels 103 and 103 covered with the organic layer pattern 104r (104g or 104b) adjacent in the row direction p. , 104b), by narrowing the interval w1 between the pixels 103, 103 arranged in the row direction p, the pixels 103 are arranged in the central portion of each organic layer pattern 104r (104g, 104b) in the row direction p. is doing. For this reason, compared with the case where all the pixels 103 arranged in the row direction p are arranged at equal intervals, the central portion where the film thickness is stable in the organic layer pattern 104r (104g, 104b) is effectively used. Thus, a plurality of pixels 103 can be arranged in the row direction p. Further, as described above, when the display device 101 is an active matrix type and includes an auxiliary electrode, the auxiliary electrode is provided in the space w <b> 2 between the pixels 103 and 103 so that the auxiliary electrode is arranged in the array of the pixels 103. It can prevent the influence.
[0026]
Therefore, it is possible to improve the aperture ratio of the pixel 103 in the row direction p. As a result, display with high luminance can be performed, and further, the luminance can be secured and the number of pixels can be increased, so that high integration and high resolution of the display device can be achieved. .
[0027]
In the display device of the above-described embodiment, the two pixels 103 and 103 arranged in the row direction p are configured to be covered with one organic film pattern 104r (104g and 104b). However, the present invention covers three or more pixels 103 arranged in the row direction p with one organic film pattern 104r (104g, 104b), and the row direction p of each organic layer pattern 104r (104g, 104b). A configuration may be adopted in which these pixels 103 are arranged in a central portion in FIG. When the organic film patterns 104r, 104g, and 104b of each color are repeatedly arranged in the row direction p, a plurality of pixels arranged in the column direction perpendicular to the row direction p are combined into one organic film pattern 104r (104g, 104b), and the pixels 103 may be collectively arranged at the center in the column direction of each organic layer pattern 104r (104g, 104b).
[0028]
<Manufacturing method of display device>
Next, an embodiment of a manufacturing method of a display device of the present invention and a vapor deposition mask used in the manufacturing method will be described in detail with reference to the drawings. The manufacturing method of the display device described here is a method suitable for manufacturing the display device described with reference to FIG. 1. First, the configuration of the vapor deposition mask used in this manufacturing method is based on FIG. 3, and also refer to FIG. However, it will be explained.
[0029]
The vapor deposition mask 201 of the embodiment shown in FIG. 3 is a so-called metal mask. When the organic layer patterns 104r, 104g, and 104b are vapor-deposited on the substrate 102, the vapor deposition mask 201 is formed on the substrate 102 on the pixel 103 arrangement surface side. On the other hand, it is used in a state where it is arranged at a predetermined interval. The vapor deposition mask 201 is prepared for each organic layer pattern 104r, 104g, 104b.
[0030]
For example, when the vapor deposition mask 201 is used for forming the organic layer pattern 104r, the vapor deposition mask 201 has a plurality of openings 203 corresponding to the formation positions of the organic layer pattern 104r. Each opening 203 has a shape that exposes the two pixels 103 and 103 arranged in the row direction p of the substrate 102. In the column direction of the array of the pixels 103 on the substrate 102, the pixels are provided every two rows (every two rows). The interval w3 in the row direction of each opening 203 is set to such an extent that bending of the vapor deposition mask 201 can be prevented, while the interval w4 in the column direction is set to about twice the width w5 in the column direction of the opening 203. The
[0031]
Next, the manufacturing method of the display apparatus using this vapor deposition mask 201 is demonstrated based on the schematic diagram of FIG.
[0032]
The display device manufacturing method shown in this figure is a method applied when the organic film pattern 104 is formed on the substrate 102 in the display device manufacturing method described with reference to FIG. Is called.
[0033]
That is, the inside of the chamber (not shown) of the vapor deposition apparatus is separated by the shielding plate 301, and the vapor deposition source 302 is disposed below the opening 302 a formed in the shielding plate 301. The shielding plate 301 is provided with a rectangular opening 302a having a wide width in the first direction x. The width of the opening 302a in the first direction x is equal to or larger than the width of the vapor deposition region in the row direction p of the substrate 201. The vapor deposition source 302 includes a heating holder and a vapor deposition material (material constituting the organic layer pattern) filled therein, and is formed in a rectangular shape corresponding to the opening 302a of the shielding plate 301. ing. That is, the width of the vapor deposition source 302 in the first direction x is also approximately the same as the opening 302a, that is, approximately equal to or greater than the width of the vapor deposition region in the row direction p of the substrate 201. Such a deposition source 302 is arranged directly below the opening 302a so as to coincide with the opening 302a.
[0034]
The substrate 102 is held on the shielding plate 301 through the vapor deposition mask 201. The vapor deposition mask 201 and the substrate 102 are moved in a second direction y orthogonal to the first direction x while being held at a predetermined interval by members not shown here. At this time, the substrate 102 has the pixel formation surface of the substrate 102 opposed to the shielding plate 301 side, and the row direction p of the substrate 102 is matched with the first direction x which is the longitudinal direction of the vapor deposition source 302. Further, the vapor deposition mask 201 is also arranged so as to coincide with the arrangement direction of the substrate 102, and a plurality (for example, two pixels) arranged in the row direction p of the substrate 102 is shielded from each opening 203 of the vapor deposition mask 201. It is exposed to the plate 301 side.
[0035]
In the arrangement state as described above, the vapor deposition material a is evaporated from the vapor deposition source 302 disposed below the substrate 102 through the shielding plate 301 and the vapor deposition mask 203. And the vapor deposition mask 201 and the board | substrate 102 arrange | positioned in the predetermined state on this upper part are moved to the 2nd direction y, maintaining these arrangement | positioning relationships.
[0036]
As a result, a plurality of (two) pixels arranged in the row direction p of the substrate 102 are collectively exposed from each opening 203 of the vapor deposition mask 201 in the second direction y orthogonal to the row direction p. In addition, while the deposition mask 201 and the substrate 102 are relatively moved, the deposition material a that has passed through the opening 301 a of the shielding plate 301 is deposited on the substrate 102 through the opening 203 of the deposition mask 201. At this time, the opening 301a of the shielding plate 301 and the vapor deposition source 302 disposed immediately below the opening extend in the first direction x perpendicular to the second direction y, that is, the row direction p of the substrate 102. The vapor deposition material a is supplied to the entire vapor deposition region in the row direction.
[0037]
According to such a manufacturing method, as described above, a plurality of pixels arranged in the first direction x (that is, the row direction p here) orthogonal to the moving direction (second direction y) of the substrate 102 and the vapor deposition mask 201. Since the vapor deposition is performed in a state where the layers are exposed in a lump, the vapor deposition pattern formed by the vapor deposition (that is, the organic layer pattern here) extends over a plurality of pixels arranged in the row direction p on the substrate 102. It is formed in a continuous shape.
[0038]
Therefore, the opening width of the opening 203 of the vapor deposition mask 201 in the row direction p is wider and the organic layer pattern in the row direction p of the substrate 102 than in the case of forming individual organic layer patterns corresponding to each pixel. The variation in the relative film thickness ratio is reduced. That is, in the formation of the organic layer pattern by vapor deposition, as described in the section of the problem to be solved by the invention, since the peripheral portion of the pattern tends to be thinned, the area of the organic film pattern is set in the row direction p. By widening, the area ratio of the thinned portion occupying the whole is reduced, whereby the variation in the relative film thickness ratio can be reduced.
[0039]
Therefore, it is possible to expand the pixel area in the row direction p by effectively using the portion having a stable film thickness in the organic layer pattern, and it is possible to manufacture a display device with high luminance. become.
[0040]
In such a manufacturing method, the width in the first direction x in the opening 301a of the shielding plate 301 and the vapor deposition source 302 is set to be equal to or greater than the width of the vapor deposition region in the substrate 102. Thus, the vapor deposition component a can be scattered more uniformly, and the vapor deposition component a can be incident on the substrate 102 more uniformly. Then, since the substrate 102 and the vapor deposition mask 201 are moved in the second direction y orthogonal to the first direction x, it is possible to perform vapor deposition on the entire surface of the substrate 102 by one movement, thereby ensuring productivity. It is also possible to do.
[0041]
Furthermore, by forming the opening 301a of the shielding plate 301 and the vapor deposition source 302 into a corresponding rectangular shape, the vapor deposition component a scattered in the second direction y from the vapor deposition source 302 passes through the vapor deposition mask 201 side. The vapor deposition component a can be substantially only the vertical vapor deposition component. Therefore, the variation in the relative film thickness ratio of the organic layer pattern in the second direction y of the substrate 102 can be reduced.
[0042]
In addition, in each embodiment demonstrated above, although the case where an organic layer pattern was formed as a vapor deposition pattern was illustrated, this invention is not limited to this. For example, when the lower electrode layer or the upper electrode layer sandwiching the organic layer pattern is a vapor deposition pattern formed for each pixel and can be continuously formed, the electrode layer is formed with the above-described configuration. May be.
[0043]
【The invention's effect】
As described above, according to the display device of the present invention, by arranging the pixels covered with the vapor deposition pattern in the central portion of the vapor deposition pattern, all of the plurality of pixels are arranged at equal intervals. Compared to the case, a plurality of pixels can be arranged by effectively using the central portion of the vapor deposition pattern having a stable film thickness. Accordingly, it is possible to improve the aperture ratio of the pixel in the display device, further improve the luminance, and thereby achieve higher integration and higher resolution.
[0044]
In addition, according to the method for manufacturing a display device of the present invention, since the plurality of pixels arranged in the first direction orthogonal to the moving direction of the substrate and the vapor deposition mask are collectively exposed, this is performed. The vapor deposition pattern formed by vapor deposition is provided in a continuous state across a plurality of pixels arranged in one direction on the substrate. Therefore, compared to the case of forming individual vapor deposition patterns corresponding to each pixel, the opening width of the vapor deposition mask in the first direction is widened, and the variation in the relative film thickness ratio of the vapor deposition pattern in the first direction of the substrate is caused. It becomes possible to make it smaller. As a result, it is possible to obtain a display device having a larger aperture ratio and higher luminance by utilizing the uniform thickness portion.
[Brief description of the drawings]
FIG. 1 is a plan view illustrating an example of a display device of the present invention.
FIG. 2 is a cross-sectional view taken along the line AA ′ in FIG.
FIG. 3 is a configuration diagram showing an example of a vapor deposition mask used in the manufacturing method of the present invention.
FIG. 4 is a schematic diagram for explaining the production method of the present invention.
FIG. 5 is a configuration diagram of a conventional display device.
FIG. 6 is a configuration diagram of a vapor deposition mask used in a conventional manufacturing method.
FIG. 7 is a schematic diagram for explaining a conventional manufacturing method.
FIG. 8 is a diagram for explaining a problem of the prior art.
FIG. 9 is a graph of a relative film thickness ratio for explaining a problem of the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 101 ... Display apparatus, 102 ... Board | substrate, 103 ... Pixel, 104r, 104g, 104b ... Organic layer pattern (deposition pattern), 201 ... Deposition mask, 203 ... Opening part, 301 ... Shielding plate, 301a ... Opening, 302 ... Deposition source , W1 ... interval between pixels covered with organic layer pattern, w2 ... interval between pixels covered with adjacent organic layer pattern, a ... deposition material, x ... first direction, y ... second direction

Claims (2)

A plurality of pixels provided with a light emitting element having a light emitting material layer sandwiched between a lower electrode and an upper electrode are arranged on a substrate, and the upper electrode is commonly used for the plurality of pixels. In an active matrix type display device,
At least one of the material layers constituting the light emitting element is composed of a vapor deposition pattern, and the vapor deposition pattern is continuously provided in a state of covering a plurality of pixels arranged adjacent to one direction among the pixels,
The one-way interval between the pixels covered with the respective vapor deposition patterns is narrower than the one-way interval between the pixels covered with the vapor deposition pattern adjacent to the one direction of the vapor deposition patterns,
An auxiliary electrode connected to the upper electrode is provided between the pixels covered with the vapor deposition pattern adjacent in the one direction .   The display device according to claim 1,
  The vapor deposition pattern includes an organic layer pattern sandwiched between the lower electrode and the upper electrode.
  A display device characterized by that.

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