JP2001255502A - Method for manufacturing flat panel display, and its manufacturing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a flat panel display, capable of carrying out cleaning without adversely affecting the condition of the surface to be cleaned and which has high performance, as compared to conventional one by using a detergent for which there is no residue at all. SOLUTION: In the method of manufacturing the flat panel display, a drying stage and the like can be omitted, and the number of manufacturing stages can be reduced to reduce the manufacturing cost by bringing a substrate into contact with a super critical fluid or a subcritical fluid to clean the substrate in a cleaning stage. And, since no cleaning substance is left, adverse effects on the surface of the substrate can be prevented and the flat panel display having satisfactory display characteristics can be manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a flat panel display and an apparatus for manufacturing the same.

[0002]

2. Description of the Related Art As is well known, in order to improve the quality and the like of a flat panel display (hereinafter referred to as an FP display) while ensuring the stability of various performances, the condition of a substrate to be used and the like are required. It is extremely important to manufacture while maintaining good. Therefore, in each process, a cleaning process is frequently performed to maintain the reliability of the product.

Conventionally, pure water has been widely used exclusively as a cleaning agent in a cleaning process. Pure water is a liquid with very few impurity components, and has no danger, so that it is excellent in handleability.

However, in a cleaning process using pure water or the like, it has been difficult to manufacture an FP display while maintaining a good surface condition of a substrate as an object to be cleaned.

For example, in the case of a manufacturing process of a liquid crystal display (LCD) which is an embodiment of an FP display, cleaning is performed before forming an alignment film, after rubbing the alignment film, and after injecting liquid crystal into empty cells. The process is repeated. However, in a series of processes for manufacturing an LCD, even if it is desired to perform a cleaning process, it may be difficult to perform the cleaning process for various reasons. For example, immediately after assembling an empty cell by bonding a pair of substrates corresponds to this. The reason why the cleaning treatment is required immediately after the substrates are bonded to each other is that the sealing material previously applied to one of the substrates is cured by heat treatment or the like at the time of bonding. That is, when heat treatment is performed, the volatile components of the sealing material adhere to the substrate surface and contaminate the empty cells, thereby deteriorating the display characteristics of the display. However, if the empty cells are cleaned, even if a sufficient drying step is performed after the cleaning, the cleaning agent inside the empty cells cannot be completely removed, and the cleaning agent remains. As a result, deterioration of display characteristics such as clouding of the display screen is caused. Therefore, after assembling the empty cell, there is a problem that the contaminants cannot be removed even though the substrate surface is contaminated.

In the case of an electroluminescence display (ELD), which is another mode of the FP display, a cleaning treatment with pure water or the like is performed before forming the carrier transport layer and / or the light emitting layer. However, even if the drying step is performed after the cleaning, the adsorbed water remains on the substrate surface, causing black spots on the display screen. Therefore, in the case of ELD,
It has been difficult to manufacture the substrate while maintaining the surface condition of the substrate in a good condition.

[0007] The carrier transport layer is a hole transport layer or an electron transport layer. Then, depending on the thin film forming material used for the carrier transport layer, when the carrier transport layer is an electron transport layer, the light emitting layer functions as a hole transport layer on the anode side. That is, it has a layer structure of substrate / anode / light-emitting layer / electron transport layer / cathode. On the other hand, when the carrier transport layer is a hole transport layer, the light emitting layer plays a role as an electron transport layer on the cathode side. That is, it has a layer structure of substrate / anode / hole transport layer / light emitting layer / cathode. Further, recently, a three-layered ELD in which a light emitting layer as an independent layer which does not function as a carrier transporting layer is formed between the carrier transporting layers.
Has been proposed. In this case, the layer structure is substrate / anode / hole transport layer / light emitting layer / electron transport layer / cathode.

[0008] Each of the above-mentioned layers is generally formed by a vacuum evaporation method. In the vacuum deposition process when forming a film by this vacuum deposition method, the degree of contamination is considered to be low,
Other processes are more susceptible to contamination. However, it is known that cleanliness is very important because the outer surface of each layer forms an interface for electron injection or hole injection.

As described above, the pure water used in each of the cleaning treatments requires a drying step by heating, and even if a very small amount of pure water remains, the display performance is adversely affected. Is known. Therefore, development of a cleaning technique using a cleaning substance having a high detergency and not remaining has been desired.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the conventional problems, and it is possible to clean a workpiece without adversely affecting the condition of the surface of the workpiece and to remove a cleaning substance. It is an object of the present invention to provide a method and an apparatus for manufacturing an FP display having higher performance as compared with the conventional one by performing a cleaning process without any problem.

[0011]

According to a first aspect of the present invention, there is provided a method of manufacturing a flat panel display having a cleaning step of cleaning a substrate, wherein the cleaning step includes the steps of: The cleaning is performed using a supercritical fluid or a subcritical fluid.

In the above method, the supercritical fluid means a cleaning substance in a supercritical state, and the subcritical fluid means a cleaning substance in a subcritical state. Then, according to the above method, the supercritical fluid or the subcritical fluid (hereinafter sometimes abbreviated as a supercritical fluid or the like) may be taken out of the air, for example, to a temperature / critical pressure higher than the critical temperature and the critical pressure. By placing the substrate in a low-pressure environment, the phase changes such as instantaneous vaporization from the substrate surface, so that the cleaning substance does not remain on the substrate. Therefore, a drying step or the like, which is necessary in the conventional cleaning process, becomes unnecessary, and the number of manufacturing steps can be reduced. As a result, a flat panel display can be manufactured with reduced manufacturing costs and improved productivity.

Further, since the display quality does not deteriorate due to the residual cleaning agent, a flat panel display having excellent display characteristics can be manufactured. Further, in conventional cleaning agents, the substrate surface may be altered depending on the type thereof, but a supercritical fluid or the like can be cleaned without altering the substrate surface regardless of the type of the substrate. .

The above "flat panel display"
A light-receiving display such as a liquid crystal display and an electroluminescent display (E
LD) and the like, including a self-luminous display.

According to a second aspect of the present invention, there is provided a method of manufacturing a flat panel display having a liquid crystal cell having a liquid crystal layer provided between an array substrate and a counter substrate. And comprising a substrate manufacturing step of manufacturing the array substrate and the opposing substrate, and a liquid crystal cell manufacturing step of manufacturing the liquid crystal cell using the array substrate and the opposing substrate. The method includes a cleaning step of cleaning a substrate and / or a counter substrate with a supercritical fluid or a subcritical fluid.

In the above method, the liquid crystal cell manufacturing step includes:
Since there is a cleaning step of cleaning the substrate using a supercritical fluid or a subcritical fluid, it is not necessary to perform a drying step or the like in the liquid crystal cell manufacturing step, and the number of manufacturing steps can be reduced. As a result, a flat panel display can be manufactured with reduced manufacturing costs and improved productivity. Further, since the cleaning is performed using a supercritical fluid or the like, the cleaning substance does not remain, and as a result, it is possible to prevent the occurrence of white turbidity such as a thin black display on the display screen.

Incidentally, the array substrate means a substrate provided with electrodes and wirings, or a thin film transistor or the like as necessary. Further, the opposite substrate means a substrate provided with electrodes and necessary color filters on the substrate. Therefore, the liquid crystal cell manufacturing step is a step after performing the substrate manufacturing step of forming electrodes, wirings, and the like on the substrate, and means a series of steps until the liquid crystal cell is completed. In addition, a module step of installing a drive circuit and the like in the liquid crystal cell is not included in the liquid crystal cell manufacturing step.

According to a third aspect of the present invention, in the method of manufacturing a flat panel display according to the second aspect, the liquid crystal cell manufacturing step includes forming an alignment film on the array substrate and / or the counter substrate. An alignment film forming step of forming
Further, the cleaning step is performed immediately before or immediately after the alignment film forming step.

According to the above-described method, if a cleaning step using a supercritical fluid or the like is performed immediately before the alignment film forming step, dust and dirt on the substrate are removed, and the conventional cleaning processing is performed. There is no residual cleaning agent generated. Therefore, the alignment film can be formed favorably.

Even if the above-mentioned cleaning step is performed immediately after the formation of the alignment film, the supercritical fluid does not adversely affect the quality of the alignment film. Thus, an alignment film having good cleanliness on the film surface can be obtained. That is, when the alignment film is cleaned by the conventional liquid-based cleaning treatment method, there is a problem that the alignment film is deteriorated by a chemical action and adversely affects depending on the type of the cleaning agent. Is not deteriorated and the alignment ability is not deteriorated. Further, since no cleaning substance remains, it is possible to suppress the occurrence of disclination and flow alignment, and to manufacture a liquid crystal display having good display characteristics. Further, the number of manufacturing steps can be reduced to reduce the manufacturing cost, and the productivity can be improved.

According to a fourth aspect of the present invention, in the method of manufacturing a flat panel display according to the second aspect, the liquid crystal cell manufacturing step includes forming an alignment film on the array substrate and / or the counter substrate. An alignment film forming step to be formed; and an alignment processing step of aligning the alignment film. The cleaning step may be performed immediately before at least one of the alignment film forming step and the alignment processing step. Alternatively, it is performed immediately after.

According to the above method, in addition to the function and effect according to the third aspect of the present invention, even when the cleaning step is performed immediately after the alignment processing step, the alignment ability of the alignment film is reduced. It is possible to carry out cleaning while omitting the drying step and the like while suppressing the occurrence of drying.

According to a fifth aspect of the present invention, in the method of manufacturing a flat panel display according to any of the second to fourth aspects, in the liquid crystal cell manufacturing step, the array substrate and the counter substrate are bonded to each other. A bonding step of assembling an empty cell, and a liquid crystal injection step of injecting liquid crystal into the empty cell, further, the washing step, immediately before at least one of the bonding step or the liquid crystal injection step and And / or immediately after.

Since a substance in a supercritical fluid state has a low viscosity and a high diffusivity, it can easily penetrate into a portion where a liquid cleaning agent cannot enter. Therefore, if the cleaning step is performed immediately after the bonding step as in the above method, as a result of the supercritical fluid or subcritical fluid penetrating into the empty cell, cleaning of the inside of the empty cell is difficult with the conventional cleaning method. Becomes possible. Further, the supercritical fluid or the like immediately becomes a gaseous phase under the atmospheric pressure and does not remain in the empty cell. Therefore, according to the above method, it is possible to manufacture a flat panel display having more excellent performance such as display quality.

Further, in the conventional liquid cleaning method, since the cleaning agent deteriorates the sealing material, it is not possible to sufficiently clean liquid crystal stains and the like adhering during liquid crystal injection. However, by performing a cleaning step using a supercritical fluid or the like, it is possible to sufficiently remove liquid crystal stains attached to the liquid crystal cell surface and the liquid crystal injection port without deteriorating the sealing material.

According to a sixth aspect of the present invention, in the method of manufacturing a flat panel display according to any one of the second to fifth aspects, a resin substrate is used as the array substrate and the counter substrate. It is characterized by the following.

In the conventional liquid cleaning process, it was necessary to perform a drying step for removing the cleaning agent. Specifically, heat treatment or the like has been performed as the drying step. Because of this,
It was necessary to use a substrate having better heat resistance than a resin substrate, for example, a glass substrate (heat-resistant temperature of 600 ° C.). Further, the resin substrate is liable to be deteriorated by the chemical action of the cleaning agent. However, according to the above method, the supercritical fluid or the subcritical fluid evaporates immediately at normal temperature and normal pressure, so that there is no need to perform a drying step. Therefore, a flat panel display excellent in performance such as display characteristics can be manufactured. Further, since the supercritical fluid or the subcritical fluid does not alter the surface of the resin substrate, a flat panel display having excellent display characteristics and lighter weight can be manufactured.

In order to solve the above-mentioned problems, the invention according to claim 7 includes an electroluminescence cell including a carrier transport layer and a light emitting layer provided between a substrate with electrodes and electrodes. A method for manufacturing a flat panel display, comprising: a substrate manufacturing process with electrodes for manufacturing the substrate with electrodes; and an electroluminescence cell manufacturing process for manufacturing the electroluminescence cell using the substrate with electrodes. The cell manufacturing step includes a cleaning step of cleaning the substrate with electrodes with a supercritical fluid or a subcritical fluid.

According to the above-described method, it is possible to manufacture an EL display as a flat panel display having good display characteristics without black spots on the display screen.
In the conventional EL display, the reason why the black spot is visually recognized on the display screen is partly due to the residual cleaning agent after the conventional cleaning process. Then, even if a drying process is performed at a predetermined temperature after a cleaning process using pure water, for example, water of about the level of adsorbed water still remains on the substrate surface, and the cleaning agent on the substrate surface remains completely. Cannot be removed. However, according to the above method, since the supercritical fluid or the like is immediately vaporized under the atmospheric pressure, no cleaning substance remains on the substrate surface after cleaning. Therefore, it is possible to prevent a decrease in luminescence caused by the residual detergent. Further, since there is no need to perform a drying step for removing the cleaning substance from the substrate surface, the manufacturing cost can be reduced.
Therefore, it is possible to manufacture an EL display having excellent light-emitting properties and excellent display characteristics while reducing the manufacturing cost and improving the productivity.

According to an eighth aspect of the present invention, in the method of manufacturing a flat panel display according to the seventh aspect, in the electroluminescent cell manufacturing step, the carrier transport layer is formed on the substrate with electrodes. A carrier transporting layer forming step, and a light emitting layer forming step of forming a light emitting layer on the carrier transporting layer, further comprising the washing step, at least one of the carrier transporting layer forming step and the light emitting layer forming step The step is performed immediately before and / or immediately after the step.

According to a ninth aspect of the present invention, in the method of manufacturing a flat panel display according to the seventh aspect, the electroluminescent cell manufacturing step includes forming the light emitting layer on the substrate with electrodes. A layer forming step, and a carrier transporting layer forming step of forming a carrier transporting layer on the light emitting layer, further comprising the washing step, at least one of the carrier transporting layer forming step or the light emitting layer forming step The process is performed immediately before and / or immediately after the step.

According to the method for manufacturing a flat panel display according to claim 8 or 9, when forming the carrier transporting layer or the light emitting layer, immediately before the forming step and / or
Alternatively, by performing a cleaning step using a supercritical fluid or the like immediately thereafter, the cleanliness of the interface between the substrate with electrodes or the electrode and the carrier transport layer or the light emitting layer can be extremely increased. This can reduce the barrier for injecting carriers (electrons or holes) from the electrodes, and can manufacture an EL display with good emission intensity.

According to a tenth aspect of the present invention, in the method for manufacturing a flat panel display according to any one of the seventh to ninth aspects, the step of fabricating the electroluminescence cell comprises the steps of: A laminating step of laminating the substrate with electrodes and a pair of opposing substrates, wherein the cleaning step is performed immediately before and / or immediately after the laminating step.

According to an eleventh aspect of the present invention, in the method of manufacturing a flat panel display according to any one of the seventh to tenth aspects, the carrier transport layer is a hole transport layer or an electron transport. Characterized in that it is a layer.

According to a twelfth aspect of the present invention, in the method for manufacturing a flat panel display according to any one of the first to eleventh aspects, a resin substrate is used as the substrate with electrodes and the counter substrate. It is characterized by doing.

In the method of manufacturing an FP display according to the present invention, since cleaning is performed using a supercritical fluid or the like, there is no need to perform a drying step at a high temperature, and the surface of the resin substrate is not deteriorated. Therefore, as described above, a resin substrate can be used as the substrate with electrodes and the counter substrate. As a result, a flat panel display having excellent display characteristics and lighter weight can be manufactured.

According to a thirteenth aspect of the present invention, in the method for manufacturing a flat panel display according to any one of the first to twelfth aspects, the supercritical fluid or the subcritical fluid is in a supercritical state. Characterized by using carbon dioxide.

According to the above-mentioned method, carbon dioxide has an appropriate critical temperature and critical pressure to bring it into a supercritical state, for example, the critical temperature is around room temperature. or,
Carbon dioxide has no toxicity or corrosiveness to the human body and is nonflammable. Therefore, since the carbon dioxide is excellent in handleability, workability and the like can be improved.

According to a fourteenth aspect of the present invention, in the method of manufacturing a flat panel display according to any one of the first to thirteenth aspects, the cleaning step is performed using a supercritical fluid or a subcritical fluid. Washing is performed a plurality of times.

As in the above-described method, the multi-stage cleaning in which the supercritical fluid or the subcritical fluid is washed a plurality of times is performed, compared with the case where the supercritical fluid or the like is retained for a predetermined time and the cleaning is performed once. Can be increased when the amount is the same, and the surface contamination of the substrate can be further removed.

According to another aspect of the present invention, there is provided an apparatus for manufacturing a flat panel display having a cleaning device for cleaning a substrate, wherein the cleaning device holds the substrate. Holding means, a cleaning tank for storing the substrate held by the holding means, and cleaning the substrate with a supercritical fluid or a subcritical fluid; and
Supply means for supplying the supercritical fluid or the subcritical fluid.

In the case of the cleaning apparatus in the manufacturing apparatus having the above structure, the supercritical fluid or the like undergoes a phase change by evaporating immediately from the surface of the substrate under the atmospheric pressure. The substrate can be cleaned without remaining. Therefore, according to the manufacturing apparatus for a flat panel display having the above-described configuration, a rinsing process and a drying process after cleaning are not required, and a cleaning device capable of cleaning by preventing residual cleaning substances is provided. A flat panel display with excellent display characteristics can be manufactured while reducing the display quality.

According to a sixteenth aspect of the present invention, in the flat panel display manufacturing apparatus according to the fifteenth aspect, the supply means is provided with a storage means for storing the supercritical fluid or the subcritical fluid. It is characterized by having.

When the storage means is independently provided as described above and is connected to the cleaning tank, the timely supply to the cleaning tank can be performed in a state where the storage means is close to a critical state to some extent. It becomes possible.

[0045]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a flat panel display according to the present invention will be described below with reference to FIGS.

The method of manufacturing a flat panel display according to the present invention is characterized in that, in the cell manufacturing step, the substrate is cleaned with a supercritical fluid or a subcritical fluid instead of the conventional pure water cleaning or the like. As a result, the number of manufacturing steps can be reduced to reduce the manufacturing cost, and the surface of the substrate as the object to be cleaned can be cleaned without deteriorating the surface and preventing residual cleaning substances.

The above-described cell manufacturing step means, for example, a liquid crystal cell manufacturing step in the case of an LCD. That is, a series of processes after performing an array substrate manufacturing process and an opposing substrate manufacturing process for forming electrodes and wirings on a substrate, and before performing a module process for installing a drive circuit and the like in a liquid crystal cell. (See FIG. 1). For ELD, EL
It refers to a cell manufacturing process, more specifically, a series of processes after the manufacturing process of the substrate with electrodes and before the module process of installing a drive circuit and the like in the EL cell.

In the present specification, the supercritical fluid means a cleaning substance in a supercritical state. More specifically, the temperature and pressure are increased from a state in which a gas phase and a liquid phase are present. As a result of exceeding the critical temperature Tc and the critical pressure Pc, the fluid is in a state in which a gas-liquid interface disappears and becomes a single phase rich in fluidity. A supercritical fluid has a density close to that of a liquid and a large diffusion constant close to that of a gas, which causes a large dissolving power of the supercritical fluid. That is, when a certain medium dissolves another substance, two factors, that is, a large number of medium molecules and a large penetrating force of the medium molecules, are factors that increase the dissolving power. Further, the above-mentioned subcritical fluid means a cleaning substance in a subcritical state, and more specifically, a fluid in which one of temperature and pressure exceeds Tc and Pc.

As the cleaning substance used,
There is no particular limitation, and conventionally known substances can be used. Specifically, for example, carbon dioxide (Tc
= 31 ° C., Pc = 75.3 × 10 5 Pa), propane (Tc = 96.7 ° C., Pc = 43.4 × 10 5 Pa),
Ethylene (Tc = 9.9 ° C., Pc = 52.2 × 10 5 P
a) and the like. Here, in the present invention, CO2 can be suitably used as a cleaning substance. This is because CO2 has an appropriate critical temperature and critical pressure to bring it to a supercritical state, such as a lower critical temperature compared to others that can be used as a cleaning substance. Also, CO2 has no toxicity to the human body and is excellent in handling properties such as nonflammability.

The substrate is not particularly limited, and various conventionally known substrates can be used. Particularly, in the case of a resin substrate, some cleaning agents have disadvantages such as altering the surface of the substrate, but such a problem does not occur when a supercritical fluid or the like is used. Therefore, it is possible to preferably perform a cleaning process on the resin substrate. In addition to the case of the resin substrate, even if the substrate has a thin film made of a polymer or the like formed on the surface, the supercritical fluid or the like does not alter the thin film as described above. can do. Furthermore, in the conventional cleaning method, a heat treatment or the like is performed for the purpose of removing the remaining cleaning agent, so that the substrate to be used needs to have a certain degree of heat resistance. However, when a cleaning substance having a critical temperature close to room temperature, such as carbon dioxide, is used, it can be suitably applied to a substrate having low heat resistance.

In the washing step, washing with a supercritical fluid or the like can be performed plural times. In this case, even if the same amount of the supercritical fluid is used, the cleaning efficiency can be increased by performing the cleaning in a plurality of times compared to the case where the cleaning is performed once by staying for a predetermined time. Thereby, the surface contamination of the substrate can be further removed.

Hereinafter, as specific examples of the flat panel display, manufacturing methods for an LCD and an ELD will be described.

(1) Liquid Crystal Display FIG. 1 is a flow chart for explaining the LCD manufacturing process. The liquid crystal cell manufacturing step in the LCD manufacturing method includes a pixel electrode such as ITO (Indium Tin Oxide) or a TF.
An array substrate having T (Thin Film Transistor) or the like;
This refers to a step of performing a series of processes described below using a counter electrode and a counter substrate having a color filter and the like as a starting material.

Specifically, first, an array substrate manufactured in the array substrate manufacturing process is prepared, an alignment film material is applied, dried and baked to form an alignment film having a predetermined film thickness (alignment film). Film forming step). On the other hand, an alignment film is also formed on the counter substrate manufactured in the counter substrate manufacturing step in the same manner as described above.

Next, the alignment film formed on the array substrate and the counter substrate is subjected to an alignment process by, for example, a rubbing process (alignment process). Further, a thermosetting sealing material or the like is printed on one of the array substrate and the counter substrate, and the spacers are dispersed. The sealing material is formed so that the application shape becomes a frame-shaped pattern lacking the liquid crystal injection port. Further, the two substrates are bonded together so that the alignment films face each other, and the seal is cured by heating to assemble an empty cell (bonding step).

Subsequently, a liquid crystal material or the like is injected into the empty cell by, for example, a vacuum injection method, and then the liquid crystal injection port is sealed to produce a liquid crystal cell (liquid crystal injection step).

Further, by mounting a drive circuit and the like on the liquid crystal cell (module process), the LCD according to the present embodiment can be manufactured.

Here, the cleaning step, which is a main part of the present invention, can be performed immediately before the above-mentioned alignment film forming step. In this case, the cleaning step aims at removing dust, dirt, organic substances, and the like attached to the array substrate. In the conventional liquid cleaning method, it is necessary to sequentially perform a rinsing step and a drying step after the cleaning processing. For example, in the case of performing pure water cleaning, it is necessary to remove pure water remaining on the substrate. In addition, a drying step and a draining step were required. However, in the supercritical fluid cleaning method, when the substrate is taken out from the cleaning tank under atmospheric pressure, the supercritical fluid or the like is immediately vaporized from the surface of the substrate, so that the cleaning substance does not remain. Therefore, an alignment film can be formed on the substrate surface while improving film-forming properties and adhesion. Further, since the ITO, TFT, and the like formed on the substrate are not deteriorated, the display characteristics are not deteriorated.

The cleaning step can be performed immediately after the alignment film forming step. As described above, cleaning with a supercritical fluid or the like does not alter and deteriorate the alignment film, and there is no residual cleaning substance. Can be removed. As a result, it is possible to suppress the occurrence of white turbidity such as a thin black display and the occurrence of flow alignment, and to manufacture a liquid crystal display having excellent display characteristics. Further, since a drying step after washing is not required, the number of manufacturing steps can be reduced, and the manufacturing cost can be reduced.

Further, the washing step can be performed immediately after the alignment treatment step. Thereby, for example, dust or dust (specifically, dust of the alignment film) generated when a rubbing process is performed as the alignment process can be sufficiently removed without deteriorating the alignment film. Thereby, it is possible to prevent the alignment film from deteriorating even during cleaning after the alignment treatment, and to minimize the occurrence of white turbidity such as thinning of black display and the occurrence of flow alignment. Obtainable. In addition, a drying step or the like, which is indispensable in the liquid cleaning method, becomes unnecessary, and the number of manufacturing steps can be reduced, and the manufacturing cost can be reduced.

In addition, the above-described cleaning step can be performed immediately after the bonding step to clean empty cells. As described above, in the bonding step, heat treatment is performed to thermally cure the sealing material. At this time, it is known that volatile components of the thermosetting sealing material adhere to the substrate and become contaminated. Further, at the time of bonding, dust and the like also enter the empty cells. In the conventional cleaning process, it is impossible to remove contaminants and dust by entering into empty cells and the like,
Further, even if the cleaning is performed, there is a very high possibility that the cleaning agent remains in the empty cells, and there is a problem that the display performance is deteriorated such that a part of the display screen becomes cloudy.
For this reason, the conventional cleaning process has not been able to clean the empty cells. However, in the supercritical fluid cleaning method, the cleaning substance in a supercritical fluid state is
Since it has low viscosity and high diffusivity, it easily penetrates into parts where liquid cleaning agents cannot enter. Therefore, contaminants existing inside the empty cells can be easily removed.
Further, the supercritical fluid is immediately vaporized at normal pressure and does not remain inside the empty cell, so that a flat panel display with further excellent display performance can be manufactured.

An empty cell is manufactured by precisely designing and controlling the cell gap, and is a structure in which free deformation is not allowed. On the other hand, in the present invention, when, for example, CO2 is used as the cleaning substance, since the critical temperature of CO2 is around 31 ° C. near normal temperature as described above, large thermal stress is applied to the empty cells during cleaning. No generation occurs, and no deformation of empty cells due to thermal stress occurs. Therefore, the cell gap in the substrate surface of the empty cell does not vary, and a liquid crystal display having good display characteristics can be manufactured.

Furthermore, the above-mentioned cleaning step can be performed immediately after the liquid crystal injection step. This makes it possible to remove liquid crystal stains attached to the surface of the panel and the liquid crystal injection port during the liquid crystal injection step.

(2) Electroluminescence Display FIG. 2 is a flow chart for explaining an ELD manufacturing process. An ELD has various aspects in its layer structure, but basically has a structure in which an anode, a carrier transport layer (a hole transport layer or an electron transport layer), a light emitting layer, and a cathode are stacked on a substrate. have. And EL in ELD
The cell manufacturing step refers to a step of performing a series of processes described later using a substrate with an electrode having an anode or the like as a starting material.
In addition, one or more layers such as an electron transport layer may be included as necessary in addition to the above-described layers, and all conventionally known EL display technologies can be used in addition to the above-mentioned essential structure.

The EL cell manufacturing process in the ELD is as follows. First, in the step of manufacturing a substrate with electrodes, an anode made of, for example, ITO is formed on the substrate to manufacture a substrate with electrodes. Subsequently, a hole transport layer as a carrier transport layer is formed on the substrate with electrodes by a conventionally known method (carrier transport layer forming step).

Next, a light emitting layer having a light emitting function is formed on the hole transport layer (light emitting layer forming step). As a method for forming the light emitting layer, a conventionally known method, for example, an evaporation method, a spin coating method, a casting method, an LB method, or the like can be adopted. Further, a method of forming a light emitting layer to be developed in the future can be adopted. Subsequently, a cathode (electrode) made of, for example, aluminum or the like is formed on the light emitting layer by a conventionally known method,
An EL cell is manufactured. Furthermore, it is also possible to form an EL cell in which after forming the cathode, an opposing substrate paired with the substrate with electrodes is attached to the cathode side.

Further, an ELD according to this embodiment can be manufactured by mounting a drive circuit or the like on the EL cell (module process).

Here, the washing step can be performed immediately before the formation of the hole transport layer. In this case, the purpose of the cleaning step is to remove dust, organic substances, and the like attached to the substrate. Further, since the supercritical fluid or the like is vaporized under the atmospheric pressure, the cleaning substance does not remain. Therefore, the cleanliness of the interface between the anode and the hole transport layer can be improved, and the barrier against injection of holes from the anode can be reduced. As a result, the emission intensity can be improved. Further, the washing step can be performed immediately after the carrier transport layer forming step. In this case, the purpose is to remove adsorbed water and the like existing on the surface. Further, the washing step can be performed immediately after the light emitting layer forming step. Thereby, the cleanliness of the interface between the light emitting layer and the cathode can be improved, and the barrier for injecting electrons from the cathode can be reduced. Therefore, the emission intensity can be further improved. Furthermore, the above-mentioned cleaning step can be performed after the bonding step of bonding the substrate with electrodes and the counter substrate to produce an EL cell.

As described above, by performing the supercritical fluid cleaning method in the fabrication of the EL cell, the interface between the anode or the cathode and the hole transport layer or the light emitting layer can be cleaned to improve the light emission intensity. it can. In addition, in the conventional cleaning method (pure water, etc.), water and the like remain on the substrate surface and the like, but in the present invention, the supercritical fluid and the like is immediately vaporized at normal temperature and normal pressure. Therefore, no cleaning substance remains. Therefore, an ELD having excellent display characteristics can be manufactured without a black spot or the like being visually recognized on the display screen. Further, since a drying step or the like is not required, the number of manufacturing steps can be reduced, and the manufacturing cost can be reduced.

It should be noted that the present invention can be applied to a method of manufacturing the above-described LCD or ELD that includes a partially different similar process. For example, in the case of using an electron transporting layer as a carrier transporting layer in an ELD, after performing a light emitting layer forming step of forming a light emitting layer on a substrate on which a cathode is formed, an electron transporting layer is formed on the light emitting layer. To form a carrier transport layer. Further, an anode is formed on the light emitting layer to manufacture an EL cell. In this case, the washing step can be performed immediately before and / or immediately after at least one of the light emitting layer forming step and the carrier transport layer forming step. In addition, depending on the layer configuration of the carrier transport layer, the light emitting layer, and the like, the above-described cleaning step can be appropriately performed immediately before and / or immediately after at least one of the steps.

[0071]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist.

(Embodiment 1) FIG. 4A is a fluid circuit diagram of a cleaning apparatus according to the present embodiment. A liquid crystal array substrate (array substrate) provided with electrodes and wirings and a color filter substrate (counter substrate) were prepared, and washed by a conventional method (pure water cleaning method). Subsequently, an alignment film precursor polymer was applied by a printing machine, and then fired to form an alignment film. Here, as the alignment film precursor polymer, Sun Ember RN-7992 (trade name, polyimide, manufactured by Nissan Chemical Industries, Ltd.) was used.

Next, using the cleaning apparatus 10 shown in FIG. 4A, a substrate group including a liquid crystal array substrate and a color filter substrate on which an alignment film and the like are formed (hereinafter, may be simply referred to as a substrate group). 2 were washed by a supercritical fluid washing method.
Specifically, it is as described below. In this example, CO2 was used as a cleaning substance.

First, a specific configuration of the cleaning apparatus 10 shown in FIG. The cleaning apparatus 10 according to the present embodiment includes:
The washing tank 1 (with an internal volume of 3 L), the supply means 20 connected to the washing tank 1 via the injection pipe 11, and the separation tank 7 connected to the washing tank 1 via the first discharge pipe 12. It is comprised including. The cleaning tank 1 has a pressure-resistant structure capable of storing an object to be cleaned.

The supply means 20 includes a carbon dioxide cylinder 3 for supplying CO 2, a high-pressure pump 4 connected to the carbon dioxide cylinder 3, a heat exchanger 5 connected to the high-pressure pump 4, A regulating valve 8 connected to the vessel 5. The high-pressure pump 4 has a function of pressurizing CO2 supplied from the carbon dioxide cylinder 3. The heat exchanger 5 has a function of heating CO2 pressurized by the high-pressure pump 4. Further, the regulating valve 8 has a function of controlling the supply of supercritical CO2.

The separation tank 7 is connected to a first discharge pipe 12 via a pressure reducing valve 6. The separation tank 7 is provided with a recovery valve 9 for discharging pollutants and a second discharge pipe 13 for discharging CO2 from a critical state to a gaseous state. Further, a gas separation membrane (trade name:
Air Dryer UM-A5, manufactured by Ube Industries, Ltd.) is provided.
It has a gas permeability coefficient of 5 cc / cm 2 · second · cmHg.

Using the cleaning apparatus 10 having the above configuration, cleaning was performed as follows. That is, first, the substrate group 2 after the firing of the alignment film set in the cassette (jig, holding means) 14 was set in the cleaning tank 1.

Next, CO 2 supplied from the carbon dioxide cylinder 3 is pressurized by the high-pressure pump 4 to a pressure (350 × 10 5 Pa) higher than the critical pressure of CO 2, and
The temperature was raised to a temperature (40 ° C.) higher than the critical temperature of O 2 to bring it into a critical state, and the regulating valve 8 was opened to supply the supercritical fluid CO 2 into the cleaning tank 1. Supercritical fluid C
The residence time of O2 in the cleaning tank 1 was 3 minutes.
This allows contaminants to be extracted into the supercritical fluid CO2,
The surfaces of the liquid crystal array substrate and the color filter substrate were washed.

Further, the supercritical fluid CO containing contaminants
2 was discharged from the first discharge pipe 12 to the outside of the washing tank 1, reduced in pressure by the pressure reducing valve 6, and sent out to the separation tank 7. In the separation tank 7, the supercritical fluid CO2 is heated at a temperature of 9 ° C. and a pressure of 9 × 10 5 P
Under the condition (a), the supercritical fluid CO2 was phase-changed into a gaseous state, whereby the dissolved contaminants were deposited, and the CO2 and the contaminants were separated. The contaminants deposited in the separation tank 7 were taken out of the separation tank 7 by opening the recovery valve 9.

The alignment films on the liquid crystal array substrate and the color filter substrate thus washed were subjected to a rubbing treatment. Further, an empty cell was produced by bonding the liquid crystal array substrate and the color filter substrate so that the cell gap was about 12 μm. Subsequently, a liquid crystal (trade name: ZLI-479) was inserted into the empty cell from a liquid crystal injection port.
2, manufactured by Merck & Co., Ltd.) to prepare a liquid crystal cell A according to the present invention.

Next, the liquid crystal orientation in the liquid crystal cell A according to the present invention manufactured as described above was evaluated. That is, a pair of polarizing plates was installed on the outer surface of the liquid crystal cell A according to the present invention so as to be in a crossed Nicols state, and observed visually. As a result, no discontinuous region was observed in the orientation of the liquid crystal, and disclination was extremely small. Further, when black was displayed, deep black was displayed, and almost no flow orientation was observed near the liquid crystal injection port. That is, it was confirmed that a liquid crystal cell having very good alignment was obtained. From these facts, it was found that cleaning of the alignment film after firing with carbon dioxide in a supercritical state was effective in improving display quality.

The washing tank 1 may be provided with a heating means for controlling the inside of the washing tank 1 to a predetermined temperature. As shown in FIG. 4 (b), the supply means 20 replaces the high-pressure pump 4 and the heat exchanger 5 with a carbon dioxide cylinder 3.
A storage tank (storage means) 21 for storing a supercritical fluid may be provided between the control valve 8 and the control valve 8. This storage means 2
1 has a pressure-resistant structure, and can pressurize to a pressure higher than the critical pressure of the cleaning substance and raise the temperature to a temperature higher than the critical temperature of the cleaning substance to make the cleaning substance a supercritical state. Pressure heating means (not shown).
With the above configuration, the supercritical fluid CO2 can be supplied to the cleaning tank 1 in a timely manner as needed. Further, a cassette (jig) 14 as the holding means is provided.
Can also hold an empty cell or a liquid crystal cell, whereby the cleaning apparatus according to the present embodiment can have a structure that can also wash an empty cell or a liquid crystal cell.

Comparative Example 1 In Comparative Example 1, a liquid crystal for comparison was obtained by performing the same steps as in Example 1 except that a conventional water cleaning treatment was performed as a substrate cleaning treatment method. Cell a was prepared. Specifically, a substrate was placed in the cleaning tank 1 used in Example 1, and approximately 5
Washing was performed for 10 minutes by injecting hot water of 0 ° C. Thereafter, the substrate was transferred to a dryer and dried sufficiently at 70 ° C.

By performing a series of manufacturing processes including the above-described cleaning treatment, a comparative liquid crystal cell a was manufactured. Further, with respect to this comparative liquid crystal cell a, the orientation was evaluated in the same manner as in Example 1. As a result, it was visually recognized that many disclinations had occurred, the black color in black display was thin, and the flow orientation was also confirmed. That is,
Compared with the liquid crystal cell A according to the present invention, the orientation was clearly deteriorated, and the display quality was not good. This is considered to be due to the fact that water was not sufficiently removed and remained during drying after the washing treatment with water, which had an adverse effect on the alignment ability of the alignment film with respect to liquid crystal molecules.

Comparative Example 2 In Comparative Example 2, a liquid crystal cell b for comparison was prepared by performing the same steps as in Comparative Example 1 except that ethanol was used as a detergent instead of water. did. Further, for this comparative liquid crystal cell b,
The orientation was evaluated in the same manner as in Example 1 above. As a result, although the disclination was slightly smaller than that of the comparative liquid crystal cell a according to the comparative example 1, the disclination occurred more frequently as compared with the liquid crystal cell A according to the present invention, the blackness in black display was slightly thinner, and the flow alignment was small. Was also confirmed. That is, as compared with the liquid crystal cell A according to the present invention, the orientation was clearly deteriorated, and the display quality was not good. The reason why the disclination of the comparative liquid crystal cell b was slightly improved as compared with the comparative liquid crystal cell a is that ethanol has a lower boiling point than water, so that ethanol is more dry than water in the drying after the washing treatment. It is considered that many were removed. On the other hand,
It is considered that the reason why the orientation was deteriorated and the display performance was deteriorated as compared with the liquid crystal cell A according to the present invention was that even ethanol was not able to be completely removed but remained.

Example 2 A liquid crystal cell according to Example 2 was manufactured in the same manner as in Example 1 except that cleaning with a supercritical fluid was performed after the rubbing treatment, not before. The liquid crystal cell according to the second embodiment thus manufactured is hereinafter referred to as a liquid crystal cell B according to the present invention. Further, the liquid crystal cell B according to the present invention was evaluated for orientation in the same manner as in Example 1 above. As a result, the disclination was extremely small, the black color in black display was dark, and the flow alignment near the liquid crystal injection port was hardly observed. That is, a liquid crystal cell having very good alignment was obtained. From these, it was found that cleaning after rubbing treatment with carbon dioxide in a supercritical state was effective in improving display quality.

Comparative Example 3 In Comparative Example 3, a liquid crystal for comparison was obtained by performing the same steps as in Example 2 except that a conventional water cleaning treatment was performed as a substrate cleaning treatment method. Cell c was prepared. Specifically, a substrate was placed in the cleaning tank 1 used in Example 2, and about 5
Washing was performed for 10 minutes by injecting hot water of 0 ° C. Thereafter, the substrate was transferred to a dryer and dried sufficiently at 70 ° C.

By performing a series of manufacturing processes including the above-described cleaning treatment, a comparative liquid crystal cell c was manufactured. Further, the comparative liquid crystal cell c was evaluated for alignment in the same manner as in Example 2 above. As a result, generation of many disclinations was visually recognized, black in the black display was thin, and flow orientation was also confirmed. That is, as compared with the liquid crystal cell B according to the present invention, the orientation was clearly deteriorated, and the display quality was not good.

Comparative Example 4 In Comparative Example 4, about 5
A liquid crystal cell d for comparison was prepared by performing the same steps as in Comparative Example 3 except that ethanol was used instead of hot water at 0 ° C. Furthermore, for this comparative liquid crystal cell d,
The orientation was evaluated in the same manner as in Example 2 above. As a result, although the disclination was slightly smaller than that of the comparative liquid crystal cell c according to Comparative Example 3, the disclination was larger than that of the liquid crystal cell B according to the present invention. Was also confirmed. That is, as compared with the liquid crystal cell B according to the present invention, the orientation was clearly deteriorated, and the display quality was not good.

Example 3 In Example 3, unlike the liquid crystal cells manufactured in the above Examples and Comparative Examples,
An L cell was fabricated. Specifically, it is as follows.

First, a transparent substrate on which a transparent electrode (anode) made of ITO was previously formed was prepared, and the transparent substrate was cleaned by the supercritical fluid cleaning method using the cleaning apparatus 10 described above.

Further, a carrier transport layer was formed on the ITO on the transparent substrate after washing. That is, in a nitrogen atmosphere, a polyvinyl carbazole / chloroform solution (300 mg / 10 ml) was spin-coated (5000 rpm × 10 seconds) on a transparent substrate, and then heat-treated at 80 ° C. to volatilize chloroform. Further, baking was performed at 120 ° C. for 30 minutes in a nitrogen atmosphere. Thus, a completely cured hole transport layer having a thickness of 0.05 μm was formed.

Next, a light emitting layer was formed on the carrier transport layer. That is, an Al oxine chelate complex / chloroform (400 mg / 10 ml) was spin-coated (5000 rpm × 10 seconds) on the carrier transport layer, and then 80 ° C.
By performing the heat treatment described above, chloroform was volatilized.
Further, baking was performed at 120 ° C. for 30 minutes in a nitrogen atmosphere. As a result, a completely cured light emitting layer was formed. Further, Al was vapor-deposited on the light-emitting layer by a vacuum vapor deposition method, and a back electrode (cathode) was formed to produce an EL cell according to the present invention.

Emission of the EL cell manufactured as described above was evaluated. That is, when a DC pulse voltage (15 V) was applied between the transparent electrode and the back electrode, clear green light emission was obtained, and almost no black spot was generated. From these, it was found that cleaning with carbon dioxide in a supercritical state was effective in improving display quality.

(Comparative Example 5) In Comparative Example 5, the IT
A comparative EL cell was prepared by performing the same treatment as in Example 3 except that the transparent substrate on which O was formed was subjected to a cleaning treatment with ethanol as a cleaning treatment method. Further, the comparative EL cell was evaluated for light emission in the same manner as in Example 3 above. As a result, the luminance was slightly lower than that of the EL cell according to Example 3, and generation of black spots was also observed. That is, it was found that the light emission was clearly inferior to the EL cell according to the present invention.

[0096]

The present invention is embodied in the form described above and has the following effects.

That is, the method of manufacturing a flat panel display according to the present invention is a method of manufacturing a flat panel display having a cleaning step of cleaning a substrate, wherein the cleaning step uses a supercritical fluid or a subcritical fluid. By washing, a drying step and the like which are required in the conventional liquid cleaning method can be omitted. Therefore, it is possible to reduce the number of manufacturing steps, reduce the manufacturing cost, and improve the productivity. Further, since no cleaning substance remains, it is possible to prevent adverse effects on the substrate surface,
There is an effect that a flat panel display having good display characteristics can be manufactured.

Further, the apparatus for manufacturing a flat panel display according to the present invention cleans a substrate without leaving a cleaning substance on the substrate, so that a rinsing process or a drying process after cleaning is not required, thereby reducing the manufacturing cost. Realize. In addition, since no cleaning substance remains, a flat panel display having excellent display characteristics can be manufactured.

[Brief description of the drawings]

FIG. 1 is a flowchart for explaining a manufacturing process of a flat panel display according to the present invention.

FIG. 2 is a flowchart for explaining a liquid crystal cell manufacturing process according to the liquid crystal cell of the present invention.

FIG. 3 is a flowchart illustrating an EL cell manufacturing process according to the EL cell of the present invention.

FIG. 4 is an explanatory view schematically showing a cleaning apparatus according to the first embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cleaning tank 2 Substrate group 3 Carbon dioxide cylinder 4 High pressure pump 5 Heat exchanger 6 Pressure reducing valve 7 Separation tank 8 Adjustment valve 9 Recovery valve 10 Cleaning device 11 Injection pipe 12 First discharge pipe 13 Second discharge pipe 14 Cassette (holding means) 20 supply means 21 storage tank (storage means)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05B 33/04 H05B 33/04 33/10 33/10 33/14 33/14 A 33/26 33/26 Z F term (reference) 2H088 FA20 FA21 FA23 FA24 FA30 HA01 HA03 MA18 MA20 2H090 HC17 HD14 JC19 LA04 3K007 AB17 AB18 CA01 CB01 DA01 DB03 EB00 FA00 5G435 AA17 BB05 BB05 KK05

Claims (16)

[Claims] 1. A method of manufacturing a flat panel display having a cleaning step of cleaning a substrate, wherein the cleaning step is performed by using a supercritical fluid or a subcritical fluid. Method. 2. A method for manufacturing a flat panel display including a liquid crystal cell having a liquid crystal layer provided between an array substrate and a counter substrate, comprising: a substrate manufacturing step for manufacturing the array substrate and the counter substrate. And a liquid crystal cell manufacturing step of manufacturing the liquid crystal cell using the array substrate and the opposing substrate, wherein the liquid crystal cell manufacturing step includes the step of forming the array substrate and / or the opposing substrate with a supercritical fluid or a subcritical fluid. A method for manufacturing a flat panel display, comprising a cleaning step of cleaning. 3. The liquid crystal cell manufacturing step includes an alignment film forming step of forming an alignment film on the array substrate and / or the counter substrate, and further includes the cleaning step immediately before the alignment film forming step. The method according to claim 2, wherein the method is performed immediately after and / or immediately after. 4. The liquid crystal cell manufacturing step includes: an alignment film forming step of forming an alignment film on the array substrate and / or the counter substrate; and an alignment processing step of aligning the alignment film. The cleaning step may be performed immediately before at least one of the alignment film forming step and the alignment processing step, and / or
3. The method according to claim 2, wherein the method is performed immediately after. 5. The liquid crystal cell manufacturing step includes: a bonding step of bonding the array substrate and the counter substrate to form an empty cell; and a liquid crystal injecting step of injecting liquid crystal into the empty cell. The flat panel according to any one of claims 2 to 4, wherein the cleaning step is performed immediately before and / or immediately after at least one of the bonding step and the liquid crystal injecting step. Display manufacturing method. 6. A resin substrate is used as the array substrate and the counter substrate.
The method for manufacturing a flat panel display according to any one of the above items. 7. A method for manufacturing a flat panel display including an electroluminescence cell having a carrier transport layer and a light emitting layer provided between an electrode-attached substrate and an electrode, wherein the electrode-attached substrate is manufactured. A substrate manufacturing process with an electrode, and an electroluminescence cell manufacturing process of manufacturing the electroluminescence cell using the substrate with an electrode, the electroluminescence cell manufacturing process, the substrate with an electrode, a supercritical fluid or subcritical fluid A method for manufacturing a flat panel display, comprising a cleaning step of cleaning with a critical fluid. 8. The step of forming an electroluminescent cell, the step of forming a carrier transport layer on the substrate with electrodes, the step of forming a carrier transport layer, and the step of forming a light emitting layer on the carrier transport layer. The flat panel according to claim 7, further comprising: performing the cleaning step immediately before and / or immediately after at least one of the carrier transport layer forming step and the light emitting layer forming step. Display manufacturing method. 9. The electroluminescent cell manufacturing step includes: a light emitting layer forming step of forming the light emitting layer on the substrate with electrodes; and a carrier transport layer forming step of forming a carrier transport layer on the light emitting layer. The flat panel display according to claim 8, further comprising: performing the cleaning step immediately before and / or immediately after at least one of the carrier transport layer forming step and the light emitting layer forming step. Manufacturing method. 10. The electroluminescence cell manufacturing step includes a bonding step of bonding the substrate with electrodes and an opposing substrate that forms a pair with the substrate with electrodes, and the cleaning step is performed immediately before the bonding step. The method according to any one of claims 7 to 9, wherein the method is performed immediately after and / or immediately after. 11. The method for manufacturing a flat panel display according to claim 7, wherein the carrier transport layer is a hole transport layer or an electron transport layer. 12. The method for manufacturing a flat panel display according to claim 7, wherein a resin substrate is used as the substrate with electrodes and the opposing substrate. 13. A supercritical fluid or a subcritical fluid, wherein carbon dioxide in a supercritical or subcritical state is used as the supercritical fluid or the subcritical fluid.
Item 13. The method for producing a flat panel display according to item 9. 14. The method of manufacturing a flat panel display according to claim 1, wherein in the cleaning step, cleaning with a supercritical fluid or a subcritical fluid is performed a plurality of times. 15. A flat panel display manufacturing apparatus provided with a cleaning device for cleaning a substrate, wherein the cleaning device accommodates the holding means for holding the substrate, and the substrate held by the holding means. A cleaning tank for cleaning the substrate with a supercritical fluid or a subcritical fluid; and a supply unit for supplying the supercritical fluid or the subcritical fluid to the cleaning tank. apparatus. 16. The apparatus for manufacturing a flat panel display according to claim 15, wherein said supply means is provided with a storage means for storing said supercritical fluid or subcritical fluid.