JP2004209409A - Method for producing substrate, droplet discharging device, organic electroluminescence display, and electronic equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a substrate by which a required sufficient amount of a solution can be applied to the coating regions divided by partitions on a substrate, to provide a droplet discharging device for realizing the method for producing the substrate, to provide a method for producing an organic electroluminescence display including the method for producing the substrate, to provide an organic electroluminescence display, and to provide electronic equipment comprising the organic electroluminescence display. <P>SOLUTION: Among the three coating regions 270R, 270G and 270B divided by partitions, a main scanning as for the discharge of droplets is performed to the coating region 270B having a large area for a plurality of times. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a substrate, in particular, a method for manufacturing a substrate for applying a droplet containing an organic electroluminescent material or the like, in a region partitioned by a partition formed on the substrate, a droplet discharge device, The present invention relates to a method for manufacturing an organic electroluminescence display device, an organic electroluminescence display device, and electronic equipment.
[0002]
[Prior art]
A matrix display type organic EL (electroluminescence) display panel generally has a structure having a thin film layer such as an organic EL layer and a hole injection layer. As one of the methods of forming this kind of thin film layer, a droplet discharge method is known. In the case where the organic EL layer is formed by a droplet discharging method, first, a droplet containing an organic EL material is separated by a droplet discharging device into a region partitioned by a partition formed on a substrate (hereinafter, referred to as a “coating region”). ) To apply the liquid droplets to the application area. Next, the applied droplet is dried to evaporate the solvent contained in the droplet, so that an organic EL layer is formed in the application region (for example, see Patent Document 1).
[0003]
[Patent Document 1]
JP 2001-291584 A
[0004]
By the way, in a part of a color display type organic EL display panel, a red EL layer that emits red light, a green EL layer that emits green light, and a blue EL layer that emits blue light are regularly arranged. There is one that realizes full-color display by additively mixing the emission colors of the layers. However, even if each of the red EL layer, the green EL layer, and the blue EL layer emits light under the same condition, their luminance is not always the same. For example, the luminance of the blue EL layer is In some cases, the luminance is lower than the luminance of the EL layer of another color. In such a case, even if the generated light emitted from each EL layer is simply added and mixed, the luminance of the blue light becomes relatively low, and there is a problem that color display cannot be performed well. As a technique for coping with this, a technique is known in which a region corresponding to the blue EL layer is made wider than a region corresponding to another color, and the emission region of blue light is relatively large. As a result, it is possible to satisfactorily perform color display on the entire panel without improving the organic EL material itself.
[0005]
[Problems to be solved by the invention]
However, when the droplet discharge method is used, if the area of one EL layer is widened, the amount of liquid applied to each application area increases, so that the following problem occurs. Now, as a droplet discharge device, a device that scans a discharge head at a constant speed with respect to a substrate is assumed. In this droplet discharge device, it is assumed that the amount of droplets discharged from the discharge head is “10 ng”, and the shortest cycle of droplet discharge is “T”. Further, it is assumed that the scanning time of the ejection head for one application region is “7T”. At this time, the droplet discharge device can apply a maximum of seven droplet discharges, that is, only a maximum of “70 ng” of a solution to one application region, regardless of the size of the application region. As described above, in the conventional droplet discharge apparatus, since the upper limit of the application amount is substantially defined, the application amount cannot be arbitrarily increased according to the size of the application area. As a result, the film thickness of the thin film layer formed in the application region becomes insufficient or non-uniform, which is one of the causes of the deterioration of the quality of the EL display panel.
[0006]
The present invention has been made in view of the circumstances described above, and realizes a method of manufacturing a substrate capable of applying a necessary and sufficient amount of a solution to an application area defined by partition walls, and a method of manufacturing the substrate. Discharge device for manufacturing the same, a method for manufacturing an organic electroluminescence display device including the method for manufacturing the substrate, an organic electroluminescence display device manufactured by the method for manufacturing the organic electroluminescence display device, and the organic electroluminescence display device An electronic device having:
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a method of manufacturing a substrate according to the present invention includes applying a droplet ejected from an ejection head ejecting a droplet to an application region partitioned by a partition formed on the substrate. A substrate manufacturing method for manufacturing a substrate by scanning one of a scanning body of the discharge head or the substrate with respect to the other, and discharging droplets from the discharge head and discharging the droplets from the discharge head. A scanning process of scanning the scanning body along a path in which the droplet is applied to the application region on the substrate is repeated a plurality of times for the same application region.
According to such a substrate manufacturing method, the scanning body is scanned a plurality of times on the same application region, so that a necessary and sufficient amount of the solution can be applied on the application region.
[0008]
Here, in the process of scanning the same application region, the scanning direction of the scanning body is one direction.
In the scanning process for the same application region, the scanning direction of the scanning body includes two directions opposite to each other.
[0009]
Further, it is preferable that in the scanning process for the same application region, the scanning body is scanned along different paths. In this way, by shifting the scanning path for each scanning process, the application points of the droplets are dispersed. Thereby, the solution can be applied to the application area without unevenness.
[0010]
In the above-described method of manufacturing a substrate, the amount per droplet discharged from the discharge head to the same discharge region may be different for each scanning process on the same application region. Further, in each scanning process for the same application region, a plurality of droplets are ejected from the ejection head, and for each scanning process for the same application region, the droplets are ejected to the same application region. The total amount of droplets may be different.
Thus, the amount of the droplet applied to the same application area can be changed for each scanning process, so that the solution can be arbitrarily applied according to the shape of the application area.
[0011]
Further, in the method for manufacturing a substrate, the method further includes an area obtaining step of obtaining an area of each of the application areas on the substrate, wherein the larger the application area in the area obtained in the area obtaining step, the greater the number of repetitions of the scanning process. It is preferable to set so that
In this manner, by increasing the number of scans for an application region having a larger area, the application amount per unit area of the application region can be equalized regardless of the size of the application region.
[0012]
According to the present invention, there is provided a method for manufacturing an organic electroluminescent display device, comprising the step of applying a droplet containing an organic electroluminescent material or a hole injection material, for example, by the method for manufacturing a substrate. The present invention further provides an organic electroluminescent display device manufactured by the manufacturing method, and an electronic apparatus having the organic electroluminescent display device as a display unit.
[0013]
In addition to the method of manufacturing the substrate, the present invention is a droplet discharge device that applies droplets discharged from a discharge head that discharges droplets to a coating area partitioned by a partition formed on the substrate, A droplet discharge unit configured to discharge droplets from the discharge head; and a discharge head configured to apply a droplet discharged from the discharge head by the droplet discharge unit to an application region on a substrate. Alternatively, one of the substrates includes a scanning unit that scans the scanning body with respect to the other, and a scanning control unit that controls the scanning unit to scan the scanning body a plurality of times with respect to the same application region. A droplet discharging device is provided.
According to this droplet discharge device, scanning for applying a droplet is performed a plurality of times for one region partitioned by the partition on the substrate, so that a necessary and sufficient amount of solution is applied to the region partitioned by the partition. Can be applied.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0015]
<First embodiment>
<Configuration of EL display panel>
FIG. 1 is a partial cross-sectional view of an organic EL display panel (hereinafter, referred to as “EL display panel”) to which droplets are applied by a droplet discharge device according to a first embodiment of the present invention. More specifically, this figure shows the EL display panel immediately before the formation of the hole injection layer in the process of manufacturing a color display type organic EL display panel. For convenience of explanation, the scale of each configuration shown in FIG. 1 is different from the actual scale and is changed to be suitable for the description.
[0016]
In FIG. 1, a TFT 220 for driving an EL element is formed on a substrate (base material) 210 such as glass by, for example, a low-temperature polysilicon process. The buffer layer 230 is formed so as to cover the upper surfaces of the substrate 210 and the TFT 220, but is opened at the electrode portion of the TFT 220.
[0017]
The pixel electrode 240 is, for example, a conductive film having a hole-injecting property such as Cr, Mo, Ta, and the like, in addition to a hole-injecting property. It is connected. The pixel electrode 240 functions not only as an anode of the EL element but also as a reflective layer.
[0018]
Next, the lower layer film 250 is made of an inorganic material such as a silicon oxide film, and is formed mainly between the pixel electrodes 240 so as to slightly cover the edge of the pixel electrode 240. On the other hand, the partition wall 260 is a kind of a partition having a height of about 2 μm formed on the upper surface of the lower layer film 250 and is formed by patterning an organic material such as acrylic by a photolithography technique or the like. The partition 260 divides an application region 270B to which a droplet is applied in a droplet discharge device described later. The upper surface of the pixel electrode 240 is subjected to a hydrophilic treatment, while the side wall surface of the partition wall 260 is subjected to a water-repellent treatment.
[0019]
FIG. 2 is a diagram showing the arrangement of the application areas in the EL display panel. The cross-sectional view shown in FIG. 1 corresponds to the cross-sectional view of the EL display panel taken along line AA ′ in FIG.
As shown in FIG. 2, in the EL display panel, each of the application region 270R, the application region 270G, and the above-described application region 270B is arranged in a matrix. More specifically, the application region 270R has a rectangular shape of about 50 × 150 μm, and is arranged side by side in the Y direction with its longitudinal direction facing the Y direction in the figure. It has a rectangular shape of about 50 × 150 μm, and is juxtaposed in the Y direction with its longitudinal direction facing the Y direction. On the other hand, the application region 270B has a larger area than the application regions 270R and 270G, has a rectangular shape of about 100 × 150 μm, and is arranged in the Y direction with its longitudinal direction facing the Y direction. ing.
[0020]
Each of these application regions 270R, 270G, and 270B is provided at a position corresponding to a sub-pixel that is the minimum unit of light emission in the EL display panel, and application region 270R corresponds to a sub-pixel that emits red light. , The application region 270G corresponds to a sub-pixel emitting green light, and the application region 270B corresponds to a sub-pixel emitting blue light. A set of three sub-pixels of a sub-pixel emitting red light (application region 270R), a sub-pixel emitting green light (application region 270G), and emitting blue light (application region 270B) arranged in the X direction is used to form an EL display panel. A pixel 270 as a minimum unit of display is configured.
[0021]
In FIG. 1 again, a hole injection layer having a thickness of about “60 nm” and an organic EL layer having a thickness of about “60 nm” are stacked on the pixel electrode 240 in the application region 270B in this order. Although not particularly shown, also in each of the application region 270R and the application region 270G, a hole injection layer and an organic EL layer are stacked on the pixel electrode 240 in this order.
[0022]
<Configuration of droplet discharge device>
FIG. 3 is a diagram showing a configuration of a droplet discharge device used for forming a hole injection layer. In this figure, the control unit 110 included in the droplet discharge device 100 supplies a drive signal to each of the discharge head 130, the head carriage 140, and the substrate carriage 150 according to the dot data stored in the storage unit 120. , And controls the entire droplet discharge device 100.
[0023]
FIG. 4 is a diagram schematically showing dot data stored in the storage unit 120. As shown in this figure, the dot data is data indicating whether or not each dot allocated in a matrix on the substrate 210 is a point where a droplet is ejected. In the drawing, black dots indicate that the droplet is to be ejected, whereas white dots indicate that the droplet is not to be ejected. Therefore, in each of the application region 270R and the application region 270G of the substrate 210, droplet ejection is instructed only for seven dots included in one dot row extending in the longitudinal direction. On the other hand, in the application region 270B, droplet ejection is instructed only for a total of 14 dots included in two dot rows extending in parallel with the longitudinal direction.
[0024]
Referring back to FIG. The tank 160 stores a polymer solution of about 1% including a hole injection material such as a polythiophene-based conductive polymer that injects holes into an organic EL material described later. In addition, the ejection head 130 has one nozzle, receives supply of a solution from the tank 160 in accordance with a drive signal supplied from the control unit 110, and converts the solution into “10 ng” droplets from the nozzle. Discharge. In addition, when continuously ejecting the droplets, the ejection head 130 can eject the droplets in a cycle of the time “T (s)” in the shortest time. Further, for convenience of explanation, in this embodiment, the number of nozzles is only one, and an example is shown in which the droplet ejected from the nozzle is only one kind of droplet of “10 ng”. May be provided, and a configuration may be employed in which a plurality of droplets can be selectively discharged from each nozzle.
The head carriage 140 scans the ejection head 130 in the main scanning direction (Y direction in the drawing) at a constant speed “150 / 7T (nm / s)” under the control of the control unit 110.
[0025]
On the other hand, the substrate carriage 150 holds the substrate 210 and performs sub-scanning of the substrate 210 with respect to the ejection head 130 under the control of the control unit 110. More specifically, the substrate carriage 150 sub-scans the substrate 210 in the sub-scanning direction (X direction in the drawing) each time the main scanning of the ejection head 130 by the head carriage 140 ends. Note that the substrate 210 is held by the substrate carriage 150 such that the X direction shown in FIG. 2 is parallel to the same direction as the sub-scanning direction X in FIG.
[0026]
<Operation of the droplet discharge device>
Next, an operation of applying a droplet containing a hole injection material by the droplet discharge device 100 (see FIG. 3) will be described. In this operation description, “70 ng” of the solution is applied to each of the application region 270R and the application region 270G, while “140 ng” of the solution is applied to the application region 270B.
[0027]
FIG. 5 is a diagram showing a state of the main scanning of the ejection head 130 by the control unit 110. As shown in this drawing, first, the control unit 110 performs main scanning of the ejection head 130 on each of the application regions 270R arranged in the main scanning direction Y by the head carriage 140 along the path indicated by S1 in the drawing. As described above, the scanning speed of the ejection head 130 is “150 / 7T (nm / s)”, and the length of the application region 270R in the main scanning direction Y is “150 nm”. Therefore, the time required for the main scan for one application region 270R is “7T (s)”. On the other hand, the shortest cycle required for discharging the droplet is “T (s)”. Accordingly, the droplet discharge device 100 can discharge a droplet up to seven times in one application region 270R. In addition, since the length of the application region 270G and the application region 270B in the main scanning direction Y is equal to the application region 270R, it is necessary to discharge the droplet to each of the application regions 270G and 270B up to seven times. Can be.
[0028]
When the ejection head 130 is main-scanned along the path S1, the control unit 110 sends the ejection area 130 from the ejection head 130 to the application area 270R in the drawing in accordance with the dot data stored in the storage unit 120 in the drawing. One droplet is ejected to each of the seven points indicated by. As a result, a total of about “70 ng” droplets are applied to the application region 270R. When the solvent contained in the solution applied on the pixel electrode 240 in the application region 270R volatilizes, a hole injection layer having a necessary and sufficient thickness (about 60 nm) is formed over the entire application region 270R.
[0029]
When the main scanning for the application region 270R is completed, the control unit 110 performs sub-scanning on the substrate 210 in the sub-scanning direction X so that the path of the main scanning by the ejection head 130 is S2 in the drawing. Subsequently, the control unit 110 causes the head carriage 140 to perform main scanning of the ejection head 130 along the path S2 for each of the application areas 270G arranged in the main scanning direction Y. At this time, the control unit 110 sends a total of seven drops of the liquid from the ejection head 130 to each point indicated by 1, 2,..., 7 in the application area 270G according to the dot data stored in the storage unit 120. Discharge droplets. As a result, a total of about “70 ng” droplets are applied to the application region 270G. When the solvent contained in the solution applied on the pixel electrode 240 in the application region 270G evaporates, a hole injection layer having a necessary and sufficient thickness (about 60 nm) is formed over the entire application region 270G.
[0030]
When the main scanning for the application region 270G is completed, the control unit 110 applies a droplet to the application region 270B.
By the way, in the conventional droplet discharge method, droplet application is performed by one main scan for one application region. For this reason, in the case of the droplet discharge device 100 that can apply only a maximum of “70 ng” of the solution to the application region 270B in one main scan as in this embodiment, if no measures are taken, The required “140 ng” solution cannot be applied to region 270B.
[0031]
Therefore, in the droplet discharge device 100, “140 ng” of the solution is applied to the application region 270B as follows. That is, first, when the main scanning of the application region 270G is completed, the control unit 110 performs the sub-scanning of the substrate 210 in the sub-scanning direction X such that the path of the main scanning by the ejection head 130 is S3 in the drawing. Subsequently, the control unit 110 performs the main scanning of the ejection head 130 along the path S3 for each of the application areas 270B arranged in the main scanning direction Y. At this time, the control unit 110 sends the liquid from the ejection head 130 to each point indicated by 1, 2,..., 7 of each application area 270B one by one in accordance with the dot data stored in the storage unit 120. Discharge droplets. As a result, first, “70 ng” droplets are applied to the application region 270B.
[0032]
Next, the control unit 110 performs sub-scanning on the substrate 210 in the sub-scanning direction X such that the main scanning path by the ejection head 130 is S4 in the drawing. Subsequently, the control unit 110 performs a main scan of the ejection head 130 on each of the application areas 270B along the path S4. At this time, the control unit 110 drops one droplet from the ejection head 130 to each point indicated by 8, 9,..., 14 in the application area 270B according to the dot data stored in the storage unit 120. Is discharged. In the second scan, “70 ng” droplets are further applied to the application region 270B, and a total of “140 ng” droplets are applied to the pixel electrodes 240 in the application region 270B by a total of two main scans. You. Thereafter, when the solvent contained in the solution applied on the pixel electrode 240 evaporates, a hole injection layer having a necessary and sufficient thickness (about 60 nm) is formed over the entire application area 270B.
[0033]
As described above, according to the droplet discharge device 100 according to the present embodiment, the main scanning is performed a plurality of times for one application region 270B, so that the application can be performed on the application region 270B by one main scanning. Even when it is necessary to apply a liquid amount equal to or more than the liquid amount ("70 ng" in this example), it is possible to apply the required amount of the solution without fail.
[0034]
By the way, from the viewpoint of applying a necessary and sufficient amount of the solution to the application region 270B, by increasing the diameter of the nozzle included in the ejection head 130 and increasing the amount of liquid per one drop, The main scanning can apply a necessary and sufficient solution. However, when the amount of liquid per droplet is increased in this way, the dot diameter increases, and the accuracy of applying (patterning) the droplet is reduced. In particular, when the application areas 270R, 270G, and 270B having a plurality of sizes are mixed like the substrate 210, if the size of the droplet is set according to the amount of the liquid to be applied to the large application area 270B, the small application area 270R 270G may be impaired in patterning accuracy. On the other hand, according to the present embodiment, since the main scanning is performed a plurality of times for one application region 270B, the application regions 270R, 270G, and 270B of all sizes need to be patterned with fine droplets. Can be. As a result, the amount of solution applied to the application region 270B can be increased without unduly impairing the patterning accuracy.
[0035]
In addition, in the present embodiment, since the path S3 of the first main scan with respect to the application area 270B is different from the path S4 of the second main scan, the droplet is applied by only one main scan. In comparison with the case, the application points of the droplets can be dispersed. Thus, the droplets can be applied evenly so as to cover the entire application area 270B.
[0036]
<Second embodiment>
In the above-described first embodiment, the droplet discharge device 100 that forms the hole injection layer in the manufacturing process of the EL display panel has been described. On the other hand, in the second embodiment, a droplet discharge device that forms an organic EL layer in a manufacturing process of an EL display panel will be described.
[0037]
<Configuration of droplet discharge device>
FIG. 6 is a diagram showing a configuration of a droplet discharge device used for forming an organic EL layer. In addition, among the components included in the droplet discharge device 102 shown in this drawing, the same components as those of the droplet discharge device 100 shown in FIG. 3 are denoted by the same reference numerals. Reference numeral 272 on the substrate 210 held by the substrate carriage 150 indicates a hole injection layer formed by the droplet discharge device 100 according to the first embodiment.
[0038]
The characteristic point of the droplet discharge device 102 as compared with the above-described droplet discharge device 100 is that, instead of the pair of the tank 160 and the discharge head 130, a pair of the tank 170R and the discharge head 172R, and the tank 170G The point is that each of a set of the ejection head 172G and a set of the tank 170B and the ejection head 172B are provided. More specifically, the solution tank 170R stores about 1% of a polymer solution containing a polymer organic EL material that emits red light, and the discharge head 172R discharges the solution as 10 ng droplets. The solution tank 170G stores about 1% of a polymer solution G containing a high-molecular-weight organic EL material emitting green light, and the discharge head 172G discharges the solution as 10 ng droplets. Then, the solution tank 170B stores a polymer solution of about 1% containing a high-molecular-weight organic EL material emitting blue light, and the ejection head 172B ejects the solution as 10 ng droplets. The ejection head 172R, the ejection head 172G, and the ejection head 172B are integrated, and are main-scanned in the main scanning direction Y by the head carriage 140 in a state where three are arranged.
[0039]
<Operation of the droplet discharge device>
Next, an operation of applying a droplet by the droplet discharge device 102 to the hole injection layer 272 in each of the application regions 270R, 270G, and 270B will be described. In this description of the operation, the droplet discharge device 102 applies approximately “70 ng” of a droplet containing an organic EL material that emits red light to the application region 270R, and emits green light to the application region 270G. About 70 ng of the droplet containing the material is applied, and about 140 ng of the droplet containing the organic EL material emitting blue light is applied to the application region 270B.
[0040]
Hereinafter, the main scanning of the ejection heads 172R, 172B, and 172G by the control unit 110 will be described with reference to FIGS. First, the control unit 110 performs main scanning of the ejection head 172R along the path S1 for each of the application areas 270R arranged in the main scanning direction Y. At this time, the control unit 110 discharges droplets one by one from the discharge head 172R to each of the points 1, 2,..., 7 in the drawing in the application area 270R according to the dot data stored in the storage unit 120. I do.
[0041]
As a result, about 70 ng of the solution containing the organic EL material emitting red light is applied on the hole injection layer 272 in the application region 270R. When the solvent contained in the solution applied on the hole injection layer 272 evaporates, a red organic EL layer having a thickness of about “60 nm” is formed on the hole injection layer 272.
[0042]
Next, the control unit 110 performs sub-scanning on the substrate 210 in the sub-scanning direction X such that the main scanning path by the ejection head 172G is S2 in the drawing. Subsequently, the control unit 110 performs main scanning of the ejection head 172G along the path S2 on each of the application areas 270G arranged in the main scanning direction Y. At this time, the control unit 110 discharges droplets one by one from the discharge head 172G to each point indicated by 1, 2,..., 7 in the application area 270G according to the dot data. As a result, droplets containing the organic EL material that emits green light are applied on the hole injection layer 272 in the application region 270G in a total of about “70 ng”. When the solvent contained in the solution applied on the hole injection layer 272 evaporates, a green organic EL layer having a thickness of about “60 nm” is formed on the hole injection layer 272.
[0043]
Next, the controller 110 applies a droplet to the application region 270B. Here, droplets of “140 ng” more than “70 ng” that can be applied in one main scan must be applied to the application region 270B. In order to cope with this, in the droplet discharge device 102, as described below, the main scan is performed a plurality of times for each application region 270B, so that the “140 ng” solution is applied to each application region 270B. I do.
[0044]
When the main scanning of the application region 270G is completed, the control unit 110 first sub-scans the substrate 210 in the sub-scanning direction X such that the main scanning path by the ejection head 172B is S3 in the drawing. Subsequently, the control unit 110 performs main scanning of the ejection head 172B along the path S3 on each of the application areas 270B arranged in the main scanning direction Y. At this time, the control unit 110 discharges droplets one by one from the discharge head 172B to each point indicated by 1, 2,..., 7 in the application area 270B according to the dot data. As a result, about “70 ng” of the droplet is first applied to the application region 270B.
[0045]
Next, the control unit 110 performs sub-scanning on the substrate 210 in the sub-scanning direction X such that the main scanning path by the ejection head 172B is S4 in the drawing. Subsequently, the control unit 110 performs main scanning of the ejection head 172B along the path S4. At this time, the control unit 110 discharges droplets one by one from the discharge head 172B to each of the points indicated by 8, 9,..., 14 in the application area 270B according to the dot data. In this second scan, droplets of about “70 ng” are further applied onto the hole injection layer 272 in the application region 270B, and a total of approximately “140 ng” droplets are applied in a total of two main scans. 270B.
[0046]
As described above, by performing the main scanning twice on the application region 270B, a solution containing the organic EL material that emits blue light is applied on the pixel electrode 240 in the application region 270B in a necessary and sufficient amount. Thereafter, when the solvent contained in the solution applied on the pixel electrode 240 is volatilized, an organic EL layer 274 having a constant thickness is formed over the entire application area 270B as shown in FIG.
[0047]
Hereinafter, the manufacturing process of the EL display panel will be described with reference to FIG. As described above, after the hole injection layer 272 and the organic EL layer 274 are stacked on the pixel electrode 240, the light transmittance can be sufficiently secured on the upper surface of the organic EL layer 274 by, for example, a vacuum deposition method. The electron injection layer 276 is formed to have a thickness of about the same. Here, as the electron injecting layer 276, for example, a fluoride or oxide of an alkali metal or an alkaline earth metal, a metal having a suitable work function such as Ca or Ba, or an organic material having an electron injecting property is used. It is suitable. Next, a light transmissive counter electrode 280 such as ITO is disposed above the electron injection layer 276, and a light transmissive sealing layer 290 such as epoxy resin or glass is disposed thereabove.
Through the above steps, the EL display panel 200 is manufactured.
[0048]
<Operation of EL display panel>
In the EL display panel 200, when a voltage is applied to a layer including the hole injection layer 272, the organic EL layer 274, and the electron injection layer 276, light is emitted from the organic EL layer 274. Of the emitted light, light emitted from the organic EL layer 274 to the sealing layer 290 side passes through the electron injection layer 276, the counter electrode 280, and the sealing layer 290, and is emitted toward the observer. Light emitted from the organic EL layer 274 to the substrate 210 side is reflected by the pixel electrode 240, passes through the sealing layer 290 and the like, and reaches an observer. Thus, top emission type color display is realized on the EL display panel 200.
[0049]
Here, in the EL display panel 200, each of the hole injection layer 272 and the organic EL layer 274 included in the sub-pixel emitting blue light is formed by applying liquid droplets by a plurality of main scans. Therefore, the hole injection layer 272 and the organic EL layer 274 are formed to have a necessary and sufficient film thickness over the entire coating region 270B, and a good blue light is emitted from the blue pixel. Can be. This blue light is additively mixed with red light and green light emitted from other sub-pixels included in the same pixel, and the pixel is visually recognized as a dot of a specific color by an observer.
[0050]
As described above, according to the present embodiment, even when the amount of the liquid to be applied to the application region 270B defined by the partition wall 260 is large, the solution can be applied in a necessary and sufficient amount. . This makes it possible to form the hole injection layer 272 and the organic EL layer 274 with a necessary and sufficient thickness.
[0051]
<Modifications / Improvements>
The present invention is not limited to the above-described embodiment, and various modifications and improvements can be added to the embodiment.
For example, in the above-described embodiment, an example has been described in which the main scanning is performed in one direction Y (see FIG. 5), but the main scanning may be performed in two directions. FIG. 8 is a diagram showing a state in which droplets are applied by bidirectional main scanning. As shown in this figure, first, main scanning is performed in the Y direction on the application region 270R, and then main scanning is performed on the application region 270G in the Y ′ direction opposite to the Y direction. Then, for the application region 270B, the first main scanning is performed in the Y direction, and the second main scanning is performed in the Y 'direction. By setting the directions of the continuous main scans to be opposite to each other, an operation for returning the ejection head 130 to the home position for each main scan becomes unnecessary, and the processing time can be reduced.
[0052]
In the above-described embodiment, an example has been described in which the main scanning path S3 (see FIG. 5) of the first main scanning and the second main scanning path S4 of the second main scanning are different for the main scanning over the application region 270B. The main scanning may be performed a plurality of times along the same path. When the main scanning is performed in the same route as described above, the effect of dispersing the application points of the droplets cannot be obtained, but the following effects can be obtained. That is, the droplet applied in advance is diffused in the application region 270B by the collision energy when the droplet ejected during the second main scan lands on the droplet applied by the first main scan. It has the effect of
[0053]
In addition, in the above-described embodiment, an example in which the application area 270B is scanned twice according to the dot data stored in the storage unit 120 has been described, but the invention is not limited to this. For example, when a thin film layer having a constant thickness is formed in all the application regions, a sensor or the like for detecting the area of the application region is provided in the droplet discharge devices 100 and 102, and according to the detection result by the sensor. Alternatively, the number of main scans may be increased in a larger application area. This makes it possible to equalize the amount of liquid applied to each application area per unit area regardless of the size of the area, and to form a thin film layer having a constant thickness in all application areas.
[0054]
Further, in the above-described embodiment, the example in which the droplet in the first main scan and the droplet in the first main scan with respect to the application region 270B are both “10 ng” has been described. The amount of the liquid droplets may be changed. For example, as shown in FIG. 9A, in the main scanning along the path S5 near the center line C, a “15 pl” droplet is ejected seven times, while along the path S6 far from the center line C. In the main scanning, droplets of “5 pl” may be ejected seven times. By making a difference in the total amount of droplets for each scan in this manner, even when main scanning is performed along two paths S5 and S6 that are asymmetric with respect to the center line C, the entire coating area 270B is covered. Droplets can be applied without unevenness.
Alternatively, the same effect can be obtained even if the number of times of discharging the droplet is changed for each main scan. For example, as shown in FIG. 9B, in the main scanning along the path S5, the number of ejections of the droplet (14pl) is set to seven, while in the main scanning along the path S6, the droplet (14pl) is used. The number of times of ejection in ()) may be three. Thus, even when the main scanning is performed along the two paths S5 and S6 that are asymmetric with respect to the center line C, the droplets can be applied to the entire application area 270B without unevenness.
[0055]
In the above embodiment, the scan of the substrate 210 with respect to the substrate 210 is defined as the main scan, but the scan of the substrate 210 with respect to the discharge head 130 may be defined as the main scan.
[0056]
<Electronic equipment>
Lastly, an EL display panel 200 (see FIG. 7) having a thin film layer (a hole injection layer 272 and an organic EL layer 274) formed by the above-described droplet discharge devices 100 and 102 is used as a display unit. The device will be described.
For example, FIG. 10 is an external view of a mobile phone 300 equipped with an EL display panel 200. In this figure, a mobile phone 300 includes an organic EL display device 340 including an EL display panel 200, in addition to a plurality of operation buttons 310, an earpiece 320 and a mouthpiece 330.
In addition to the mobile phone 300, the organic EL display device 340 including the EL display panel 200 includes computers, projectors, digital cameras, movie cameras, PDAs (Personal Digital Assistants), in-vehicle devices, copiers, audio devices, and the like. It can be used as a display portion of various electronic devices.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional view of an organic EL display panel in a process of manufacturing an organic EL display panel according to an embodiment of the present invention.
FIG. 2 is a diagram for explaining an application area in the organic EL display panel.
FIG. 3 is a diagram illustrating a configuration of a droplet discharge device that forms a hole injection layer in the same embodiment.
FIG. 4 is a diagram showing dot data used in the same droplet ejection apparatus.
FIG. 5 is a diagram showing a state of main scanning by the droplet discharge device.
FIG. 6 is a diagram showing a configuration of a droplet discharge device for forming an organic EL layer in the embodiment.
FIG. 7 is a cross-sectional view of the organic EL display panel according to the same embodiment.
FIG. 8 is a diagram showing a state of main scanning according to a modification of the embodiment.
FIG. 9 is a diagram showing a state of main scanning according to a modification of the embodiment.
FIG. 10 is a diagram showing a mobile phone provided with an organic EL display device including the organic EL display panel.
[Explanation of symbols]
100 droplet discharge device, 110 control unit, 130 discharge head, 140 head carriage, 150 substrate carriage, 200 EL display panel, 270R, 270G, 270B coating area, 300 mobile phone, 340 organic EL display device.

Claims (12)

In order to apply droplets discharged from a discharge head that discharges droplets to a coating area partitioned by a partition formed on a substrate, one of the discharge heads or the substrate is scanned with respect to the other. A method of manufacturing a substrate for manufacturing a substrate by
A droplet is ejected from the ejection head, and a droplet is ejected from the ejection head, and a scanning process of scanning the scanning body along a path that is applied to an application region on a substrate,
A method for manufacturing a substrate, wherein the method is repeated a plurality of times for the same application region. 2. The method according to claim 1, wherein a scanning direction of the scanning body is one in a scanning process on the same application region. 2. The method of manufacturing a substrate according to claim 1, wherein in a scanning process on the same application region, the scanning direction of the scanning body includes two directions opposite to each other. 4. The method according to claim 2, wherein in the scanning process on the same application area, the scanning body is scanned along different paths. 5. The method according to any one of claims 1 to 4, wherein the amount of droplets discharged from the discharge head to the same discharge region is different for each scanning process on the same application region. In each of the scanning processes for the same application region, a plurality of droplets are ejected from the ejection head,
6. The substrate manufacturing method according to claim 1, wherein the total amount of droplets ejected from the ejection head to the same application region is different for each scanning process on the same application region. Method. The method further includes an area obtaining step of obtaining an area of each of the application regions on the substrate,
The method of manufacturing a substrate according to claim 1, wherein the application area having a larger area acquired in the area acquiring step is set to have a larger number of repetitions of the scanning step. A method for manufacturing an organic electroluminescent display device, comprising the method for manufacturing a substrate according to claim 1. The method for manufacturing a substrate according to any one of claims 1 to 7, wherein a droplet containing either an electroluminescent material or a hole injection material for injecting holes into the electroluminescent material is applied on the substrate. A method for manufacturing an organic electroluminescent display device, comprising a step of applying the solution to a region. An organic electroluminescent display device manufactured by the method for manufacturing an organic electroluminescent display device according to claim 8. An electronic apparatus comprising the organic electroluminescence display device according to claim 10 as a display unit. A droplet discharge device that applies a droplet discharged from a discharge head that discharges a droplet to an application region partitioned by a partition formed on a substrate,
Droplet ejection means for ejecting droplets from the ejection head,
The scanning unit scans one of the discharge head and the substrate with respect to the other in a path such that the droplet discharged from the discharge head by the droplet discharge unit is applied to a coating region on the substrate. Scanning means for performing
A droplet discharge device comprising: a scanning control unit that controls the scanning unit so that the scanning body is scanned a plurality of times on the same application region.

Images