JP4313564B2 - Non-fixed side substrate manufacturing method of organic EL display panel and non-fixed side substrate manufacturing apparatus of organic EL display panel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to the manufacture of an organic EL display that has recently been viewed as a promising flat panel display (FPD).
[0002]
[Prior art]
An organic EL display is a display using an organic EL element. The organic EL element has a structure in which an organic thin film is sandwiched between a pair of electrodes, and at least one of them is a transparent electrode such as indium-tin oxide (ITO) for the purpose of extracting light. A DC voltage is applied to the pair of electrodes, and electrons are injected from one side into the organic thin film from the other. In the organic thin film, these carriers are recombined and excited, and light emission occurs when this carrier returns to the ground state.
[0003]
Since the organic EL display is self-luminous, a backlight like a liquid crystal display is unnecessary. In addition, it has excellent high-speed response and can be easily reduced in thickness and driving voltage. In addition, the manufacturing process is simple compared to a liquid crystal display or the like. For this reason, it is attracting attention as a next-generation display technology, and its practical application to mobile phones has already begun.
[0004]
The structure of the current organic EL display panel will be described with reference to FIG. FIG. 5 is a schematic cross-sectional view of a current organic EL display panel. The organic EL display panel shown in FIG. 5 includes a pair of electrodes 11 and 12, an EL element portion 1 composed of an organic thin film 13 sandwiched between the pair of electrodes 11 and 12, and a package 2 in which the EL element portion 1 is housed. It consists of. The organic EL display panel refers to an organic EL display composed of a package 2 excluding a drive circuit and the like and components inside the package 2.
[0005]
For convenience of extracting light, at least one of the pair of electrodes 11 and 12 is a transparent electrode such as ITO. In the active type in which each pixel is driven, a thin film transistor (TFT) is formed as one electrode. The package 2 includes a fixed side substrate 21 to which the EL element unit 1 is fixed and a non-fixed side substrate 22 on the side to which the EL element unit 1 is not fixed. The current organic EL display is a so-called bottom emission type, and the example shown in FIG. 5 also belongs to this. That is, the fixed side substrate 21 is made of glass and is transparent. The light from the EL element unit 1 passes through the fixed substrate 21 and is emitted. That is, the fixed substrate 21 is located on the side of the person viewing the image.
[0006]
[Problems to be solved by the invention]
Since the bottom emission type organic EL display panel as shown in FIG. 5 emits light through the fixed-side substrate 21 of the package 2, there is a problem that the light use efficiency is poor. That is, a circuit for driving the EL element unit 1 is formed on the fixed substrate 21, and light transmittance is worse than that of a normal simple transparent body. In order to solve this problem, a top emission type organic EL display panel is effective, and the top emission type is considered promising in the future. FIG. 6 is a schematic cross-sectional view of a top emission type organic EL display panel.
In the top emission type, as shown in FIG. 6, the light from each EL element unit 1 is directly emitted through the non-fixed side substrate 22. Since the non-fixed side substrate 22 does not fix the EL element unit 1, it can be a simple transparent body and can have a high transmittance. For this reason, the light use efficiency is higher than the bottom emission type.
[0007]
Here, as shown in FIG. 6, in the top emission type, it is necessary to form ribs on the periphery of the non-fixed side substrate 22. The ribs are formed by processing a transparent glass plate that is the basis of the non-fixed side substrate 22. At present, it is considered that ribs are formed by sandblasting (see Semiconductor FPD World, January 2002, p. 116-118).
However, according to the sandblasting method, as shown in an enlarged view in FIG. In particular, in the case of a structure in which light is extracted through the portion as in the top emission type, there is a problem that unevenness on the surface subjected to sandblasting causes image unevenness, flicker in image quality, and the like. Moreover, according to the sandblasting method, microcracks are likely to occur. For this reason, it is easy to produce the problem in terms of strength and durability. This point does not change even if it is a bottom emission type.
[0008]
The invention of the present application has been made to solve such a problem, and is technically significant to provide a processing technology for a non-fixed side substrate that is suitable for use in a top emission type organic EL display panel with excellent image quality. It is what has.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 of the present application manufactures a non-fixed side substrate which is a side on which an EL element part is not fixed, among packages of an organic EL display panel in which the EL element part is housed. A method,
Applying a resist to the glass plate in a predetermined pattern;
Forming a recess whose peripheral edge is a rib by etching by supplying and etching a hydrofluoric acid-based etching solution in a mist form from a nozzle onto a resist-coated glass plate ,
The pressure at which the etching solution is sprayed from the nozzle in a mist form is 0.15 MPa or more and 0.25 MPa or less .
In order to solve the above-mentioned problem, the invention described in claim 2 is a transparent non-transparent non-fixed side of the top emission type organic EL display panel package in which the EL element portion is housed. A method of manufacturing a stationary side substrate,
Applying a resist to the glass plate in a predetermined pattern;
Forming a recess having a peripheral edge as a rib by spraying and supplying a hydrofluoric acid-based etching solution in a mist form from a nozzle onto a resist-coated glass plate , and the etching solution The pressure when spraying from the nozzle in the form of a mist has a configuration of 0.15 MPa or more and 0.25 MPa or less .
Further, in order to solve the above-mentioned problems, the invention described in claim 3 is an apparatus for manufacturing a non-fixed side substrate which is a side where an EL element part is not fixed, among packages of an organic EL display in which the EL element part is housed. Because
Etching is carried out by spraying a hydrofluoric acid-based etching solution onto the surface of the glass plate by spraying it in the form of a mist onto the surface of the glass plate, where the resist is applied and facing the surface of the glass plate located at a predetermined position. An etchant supply system,
The peripheral edge is a rib formed on the surface of the glass plate by etching ,
The etching solution supply system has a configuration in which the etching solution is sprayed from a nozzle at a pressure of 0.15 MPa to 0.25 MPa .
In order to solve the above-mentioned problem, the invention described in claim 4 is a transparent non-fixing which is a side where the EL element part is not fixed in a package of a top emission type organic EL display in which the EL element part is accommodated. An apparatus for manufacturing a side substrate,
Etching is carried out by spraying a hydrofluoric acid-based etching solution onto the surface of the glass plate by spraying it in the form of a mist onto the surface of the glass plate, where the resist is applied and facing the surface of the glass plate located at a predetermined position. An etchant supply system,
The peripheral edge is a rib formed on the surface of the glass plate by etching ,
The etching solution supply system has a configuration in which the etching solution is sprayed from a nozzle at a pressure of 0.15 MPa to 0.25 MPa .
In order to solve the above-mentioned problem, the invention according to claim 5 is the configuration according to claim 3 or 4 , wherein the nozzle is provided below a glass plate positioned at a predetermined position, and an etching solution is provided above the nozzle. Is sprayed to adhere to the lower surface of the glass plate and etched.
In order to solve the above-mentioned problem, the invention according to claim 6 is the movement of supplying the etching solution uniformly by relatively moving the nozzle or the glass plate in the configuration of claim 3, 4 or 5. It has the structure of having a mechanism.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention (hereinafter referred to as embodiments) will be described.
First, an embodiment of the organic EL display panel will be described. FIG. 1 is a schematic cross-sectional view of an organic EL display panel of the present invention. The organic EL display panel shown in FIG. 1 is a top emission type, and the basic structure is the same as that shown in FIG. The difference is in the non-fixed side substrate 22. In this embodiment, the concave portion is formed by a mist etching method performed by supplying the etching solution in a mist form. The cross-sectional shape of the rib 220 is different from that formed by the sandblast method shown in FIG. That is, in the present embodiment, the rib 220 has a tapered surface on the inner side (side closer to the center of the panel). The angle of the taper surface (enlarged and indicated by θ in FIG. 1) is preferably about 80 to 87 degrees. If the taper surface has such a degree, the strength of the rib 220 can be increased while taking a sufficient area of the bottom of the recess.
[0011]
In the embodiment shown in FIG. 1, the flatness of the inner side surface 221 of the non-fixed side substrate 22 is very high as shown in an enlarged manner in FIG. This is an effect of the mist etching method. The outer surface 222 of the non-fixed side substrate 22 can ensure flatness by arbitrarily selecting various polishing methods. The inner surface is difficult to polish due to the presence of the ribs 220. In this embodiment, the flatness is very high because of the mist etching method.
Since the non-fixed side substrate 22 of the present embodiment is for a top emission type organic EL display, it is a transparent member that emits light through it. Since the flatness of the surfaces 221 and 222 is high in the present embodiment, the quality of the displayed image is high.
[0012]
Next, an embodiment of the invention of the non-fixed side substrate manufacturing method and an embodiment of the non-fixed side substrate manufacturing apparatus will be described.
FIG. 2 is a diagram illustrating a schematic configuration of the non-fixed-side substrate manufacturing apparatus according to the embodiment. The apparatus shown in FIG. 2 is located in the processing container 3 in which the etching process is performed inside, the conveyance system 4 that carries the glass plate G into the processing container 3 and unloads the glass plate G after processing, and the processing container 3. A nozzle 5 provided at a position facing the surface of the glass plate G, and an etching solution supply system 6 for etching by supplying the hydrofluoric acid-based etching solution L in the form of a mist to the surface of the glass plate G through the nozzle 5 I have.
[0013]
The transport system 4 is a roller system in this embodiment. That is, the transport system 4 is constituted by a large number of transport rollers 41 provided along the transport line. In this embodiment, the glass plate G is conveyed while the surface to be etched of the glass plate G is on the lower side. The glass plate G rides on each conveyance roller 41 at the position of the end portion that does not need to be etched.
[0014]
The nozzle 5 is provided below the transfer line in the processing container 3. The etchant supply system 6 includes a liquid reservoir 61 that stores an etchant L, a pipe 62 that connects the liquid reservoir 61 and the nozzle 5, a valve 63 and a liquid feed pump 64 that are provided on the pipe 62. Yes. Further, the bottom of the processing vessel 3 has a funnel shape, and an etching solution recovery unit 7 for recovering the used etching solution L is provided there.
[0015]
FIG. 3 is a perspective view showing the shape of the nozzle 5 shown in FIG. As shown in FIG. 3, in the present embodiment, a plurality of nozzles 5 are arranged perpendicular to the conveying direction of the glass plate G. Each nozzle 5 has a tubular shape with an injection hole 50 provided in the upper part, and is provided in parallel to each other at equal intervals in a horizontal plane. The injection holes 50 are also equally spaced in each nozzle 5.
Each injection hole 50 is elongated in a 45-degree direction oblique to the conveyance direction of the glass plate G. Therefore, as shown in FIG. 3, the etchant L sprayed from each spray hole 50 spreads in a long inverted cone shape in this direction.
The arrangement of the injection holes 50 shown in FIG. 3 is devised so that the etching solution L is uniformly supplied to the glass plate G. This point will be described with reference to FIG. FIG. 4 is a view showing that each of the injection holes 50 allows the etching liquid L to be uniformly supplied to the glass plate G.
[0016]
The middle part of FIG. 4 shows the etching solution L sprayed from each spray hole 50 of one nozzle 5. In the lower part of FIG. 4, the distribution of the injection amount of the etching liquid L from each injection hole 50 viewed in the width direction of the glass plate G is shown. When the glass plate G passes above the nozzle 5, each point on the lower surface of the glass G is supplied with the etching solution L from any of the injection holes 50. At this time, the point P passing just below the intermediate position between the two adjacent injection holes 50 is supplied with the etching solution L from the two adjacent injection holes 50. In this case, since this point P is located at the end of the reverse-propagating etching solution L, the amount of the etching solution L received from one injection hole 50 is different from that shown in FIG. About half of the point, the supply of the etching solution L for one injection hole 50 is received by the injection holes 50 on both sides. Therefore, the supply amount of the etching liquid L at each point of the glass plate G is uniform.
[0017]
A resist coating machine (not shown) is provided on the front side of the processing container 3 on the transfer line. A cleaning machine (not shown) is provided behind the processing container 3 on the transfer line. As the resist coating machine and the cleaning machine, the present ones can be arbitrarily selected and employed.
The apparatus shown in FIG. 2 includes a moving mechanism that moves the glass plate G with respect to the stationary nozzle 5 in order to uniformly supply the etching solution L to the glass plate G. The moving mechanism is also used by the transport system 4. That is, among the transport rollers 41 constituting the transport system 4, the one provided in the processing container 3 constitutes a moving mechanism.
[0018]
In FIG. 2, a glass plate G having a predetermined shape coated with a resist in a predetermined pattern by a resist coating machine (not shown) is carried into the processing container 3 by the transport system 4. While the etching liquid L is sprayed from each nozzle 5, the transfer roller 41 in the processing container 3 moves the glass plate G to pass above each nozzle 5. At this time, the mist-like etching solution L adheres to the lower surface of the glass plate G. Thereby, the lower surface of the glass plate G is slightly etched.
[0019]
The conveyance roller 41 in the processing container 3 stops the glass plate G after the glass plate G has passed over the nozzles 5, and this time moves (retreats) in the opposite direction. Then, when the glass plate G passes through the nozzles 5 again, the mist-like etching solution L adheres. Thereby, the lower surface of the glass plate G is further slightly etched. The conveyance roller 41 in the processing container 3 passes the glass plate G over the nozzles 5 and then temporarily stops, reverses it, and moves it again in the conveyance direction (advances). Such reciprocating motion is repeated several times, and etching is performed little by little while adhering the mist-like etching solution L little by little. When the reciprocating motion is performed a number of times that etching can be performed at a predetermined depth, the glass plate G is unloaded from the processing container 3. Thereafter, the glass plate G is carried into a cleaning machine (not shown). In the cleaning machine, pure water is supplied to the surface of the glass plate G, and the remaining etching solution L and the like are washed away. A large glass plate G may be processed in a lump and then cut into one non-fixed side substrate 22.
[0020]
According to such a mist etching method in which the etching solution L is supplied in a mist form, the flatness of the etched surface is increased. As the wet etching method, a dip method in which an object is immersed in an etching solution is often used. However, according to the research of the inventors, the dip method has poor flatness, and the non-fixed side substrate of the top emission type organic EL display panel is not suitable. It cannot be adopted for manufacturing. According to the mist etching method in which etching is performed by depositing an etching solution in the form of a mist, etching with sufficiently high flatness can be performed for manufacturing a non-fixed side substrate of a top emission type organic EL display panel. As described above, the inner surface of the rib 220 becomes a tapered surface because of wet etching. Since wet etching proceeds isotropically, a suitable tapered surface can be obtained.
[0021]
Further, in the present embodiment, the etching surface of the glass plate G is directed downward, and the etching solution L is sprayed from below to be attached. This point also contributes to etching with high flatness. If the liquid is ejected from above, a problem occurs when a droplet of a certain size is discharged due to an abnormality such as the pressure of the liquid feed pump 64. That is, the etching liquid adheres to the surface to be etched in the state of a droplet having a certain size, and the etching proceeds abnormally much at the portion where the droplet has adhered, resulting in a decrease in flatness. There is no such a problem if it is a type injecting from below.
[0022]
Details of the apparatus and method according to the above configuration will be described.
The etching solution is basically hydrofluoric acid based, although it varies slightly depending on the material of the glass plate G that is the object. For example, those sold by Morita Chemical Co., Ltd. can be used. As the glass plate G, so-called blue plate, white plate, soda lime glass, borosilicate glass, and the like can be considered, but all can be etched with a hydrofluoric acid-based etching solution.
[0023]
The resist needs to have corrosion resistance to hydrofluoric acid. For example, FH-890K manufactured by Fuji Photo Film Arch Co., Ltd. can be used. For the application of the resist, for example, a known method such as screen printing can be employed.
The size of the hole of the nozzle 5 for injecting the etching solution in the form of a mist is, for example, about 80 to 150 mm in width (indicated by W in FIG. 3) and about 100 to 150 mm in length (indicated by Lg in FIG. 3). Good. The injection pressure may be about 0.15 MPa to 0.25 MPa.
[0024]
In the above embodiment, the etching solution L is uniformly supplied while moving the glass plate G. However, the nozzle 5 may be moved in a plane parallel to the glass plate G with respect to the stationary glass plate G. The movement of the glass plate G and the movement of the nozzle 5 may be used in combination.
The organic EL display has a configuration in which EL element portions of three colors of RGB are individually formed, a combination of a blue EL element portion and a color conversion film emits each color of RGB, and a white EL element portion. And any combination of color filters.
Moreover, although the top emission type was taken up in the said embodiment, this invention can be implemented also about a bottom emission type. Even in this case, since the processing of the non-fixed side substrate constituting the package is performed not by the sandblasting method but by the wet etching method, there is an effect that the problem of strength and the problem of durability do not occur.
[0025]
【The invention's effect】
As described above , according to the method according to claim 1 or the apparatus according to claim 3 of the present application, since the processing of the non-fixed side substrate constituting the package is performed by the wet etching method instead of the sandblasting method, Thus, an organic EL display that does not cause the above-described problems and durability problems can be manufactured .
Moreover, according to the method of Claim 2 or the apparatus of Claim 4 , in addition to the said effect, since it is a top emission type, an organic electroluminescent display with high utilization efficiency of light can be manufactured. Therefore, a bright image can be obtained with low power consumption. In addition, the non-fixed side substrate has a recess having a bottom surface that transmits light from the EL element portion formed by etching performed by supplying an etching solution in a mist form. Is expensive. For this reason, an organic EL display capable of displaying a high-quality image free from image quality unevenness and flickering can be manufactured .
Further, according to the apparatus of the fifth aspect , since the nozzle sprays the etching solution from below and supplies it to the glass plate, etching with higher flatness can be performed. For this reason, it is possible to contribute to high-quality image display in which image quality unevenness and flicker are further reduced.
According to the sixth aspect of the present invention, since the moving mechanism for moving the nozzle or the glass plate relatively is provided, a more uniform etching solution can be supplied. For this reason, it is possible to contribute to high-quality image display in which image quality unevenness and flicker are further reduced.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of an organic EL display panel of the present invention.
FIG. 2 is a diagram illustrating a schematic configuration of a non-fixed-side substrate manufacturing apparatus according to an embodiment.
3 is a perspective view showing the shape of the nozzle 5 shown in FIG. 2. FIG.
4 is a view showing that each injection hole 50 is configured to uniformly supply an etching solution L to a glass plate G. FIG.
FIG. 5 is a schematic cross-sectional view of a current organic EL display panel.
FIG. 6 is a schematic cross-sectional view of a top emission type organic EL display panel.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 EL element part 2 Package 21 Fixed side board | substrate 22 Non-fixed side board | substrate 3 Processing container 4 Conveyance system 41 Conveyance roller 5 Nozzle 50 Injection hole 6 Etching liquid supply system G Glass plate L Etching liquid

Claims (6)

A method of manufacturing a non-fixed side substrate which is a side where an EL element part is not fixed among packages of an organic EL display panel containing an EL element part therein,
Applying a resist to the glass plate in a predetermined pattern;
Forming a recess whose peripheral edge is a rib by etching by supplying and etching a hydrofluoric acid-based etching solution in a mist form from a nozzle onto a resist-coated glass plate ,
The method for producing a non-fixed side substrate of an organic EL display panel, wherein the pressure when spraying the etching solution in a mist form from a nozzle is 0.15 MPa or more and 0.25 MPa or less . Among the top emission type organic EL display panel packages that house the EL element portion therein, a method for manufacturing a transparent non-fixed side substrate that is a side where the EL element portion is not fixed,
Applying a resist to the glass plate in a predetermined pattern;
Forming a recess having a peripheral edge as a rib by spraying and supplying a hydrofluoric acid-based etching solution in a mist form from a nozzle onto a resist-coated glass plate , and the etching solution A method for producing a non-fixed-side substrate of an organic EL display panel, wherein the pressure when sprayed in a mist form from a nozzle is from 0.15 MPa to 0.25 MPa . Among the organic EL display packages containing the EL element part inside, it is an apparatus for manufacturing a non-fixed side substrate which is a side where the EL element part is not fixed,
Etching is carried out by spraying a hydrofluoric acid-based etching solution onto the surface of the glass plate by spraying it in the form of a mist onto the surface of the glass plate, where the resist is applied and facing the surface of the glass plate at a predetermined position An etchant supply system,
The peripheral edge is a rib formed on the surface of the glass plate by etching ,
The apparatus for producing a non-fixed side substrate of an organic EL display panel, wherein the etching solution supply system is one for injecting the etching solution from a nozzle at a pressure of 0.15 MPa to 0.25 MPa . Among top emission type organic EL display packages that house an EL element portion therein, an apparatus for manufacturing a transparent non-fixed side substrate that is a side where the EL element portion is not fixed,
Etching is carried out by spraying a hydrofluoric acid-based etching solution onto the surface of the glass plate by spraying it in the form of a mist onto the surface of the glass plate, where the resist is applied and facing the surface of the glass plate at a predetermined position An etchant supply system,
The peripheral edge is a rib formed on the surface of the glass plate by etching ,
The apparatus for producing a non-fixed side substrate of an organic EL display panel, wherein the etching solution supply system is one for injecting the etching solution from a nozzle at a pressure of 0.15 MPa to 0.25 MPa . The nozzle is provided below the glass plate located in a predetermined position, according to claim 3 or 4 above etching solution is sprayed on to adhere to the lower surface of the glass plate and characterized in that the etching The manufacturing apparatus of the non-fixed side board | substrate of the organic electroluminescent display panel of description. 6. A non-fixed-side substrate of an organic EL display panel according to claim 3 , further comprising a moving mechanism that uniformly moves the nozzle or the glass plate to uniformly supply an etching solution. Manufacturing equipment.

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