JP2005099270A - Method and apparatus for manufacturing liquid crystal display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a liquid crystal display panel while preventing water from being mixed with liquid crystal even in the case of a large-sized mother board and further with good productivity. <P>SOLUTION: The manufacturing method for the liquid crystal display panel includes a seal material arrangement step of arraying a seal material on a main surface of one or both of substrates to be laminated together, a liquid crystal dripping step of dripping liquid crystal on one of the two substrates, and a laminating step of laminating the two substrates together, wherein a degassing step in which the substrate where at least the liquid crystal should be dripped, between the two substrates, is arranged in a pressure reduced atmosphere before the liquid crystal dripping step, and a releasing step in which the pressure reduced atmosphere is released with inert gas before the laminating step, are included. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a liquid crystal display panel manufacturing method and a liquid crystal display panel manufacturing apparatus. In particular, the present invention relates to a manufacturing method and a manufacturing apparatus of a liquid crystal display panel manufactured by a liquid crystal dropping method.

  The liquid crystal display panel has a configuration in which liquid crystal is sealed between two substrates facing each other. FIG. 7 shows a schematic cross-sectional view of an example of a color liquid crystal display panel among the liquid crystal display panels. The liquid crystal 30 is enclosed between a TFT (Thin Film Transistor) substrate 1 and a CF (Color Filter) substrate 5 and enclosed. A scanning line driving circuit 2 is formed on the main surface of the TFT substrate 1 and connected to an external driving IC (not shown). A pixel electrode layer 3 is formed on the main surface of the scanning line driving circuit 2. In addition to the pixel electrode, a TFT is formed on the pixel electrode layer 3. An alignment film 4 is formed on the main surface of the pixel electrode layer 3.

  A color filter 6 is formed on the main surface of the CF substrate 5 which is the substrate opposite to the TFT substrate 1. The color filter 6 has three colors of red, green, and blue. A counter electrode 7 is formed on the main surface of the color filter 6. An alignment film 8 is formed on the main surface of the counter electrode 7. The liquid crystal 30 is filled so as to be sandwiched between the alignment film 4 and the alignment film 8, and a sealing material 31 is disposed on the side of the liquid crystal 30. That is, the liquid crystal 30 is sealed so as to be surrounded by the alignment films 4 and 8 and the sealing material 31. The gap between the alignment film 4 and the alignment film 8 is kept constant by sandwiching the spacer 9. Thus, the liquid crystal 30 is in direct contact with the alignment films 4 and 8 and the sealing material 31. The two substrates are bonded and fixed to each other by a sealing material 31. In the present specification and claims, a single substrate such as a TFT substrate as well as a single substrate on which a pixel electrode layer, an alignment film, and the like are formed are simply referred to as a “substrate”.

  As one of liquid crystal display panel manufacturing methods, there is a manufacturing method called a liquid crystal dropping method as one of liquid crystal injection methods. FIG. 8 shows a process diagram of the liquid crystal dropping method. First, an alignment film is formed after forming color filters, pixel electrode layers, and the like on two substrates. Next, a sealing material is disposed on the main surface of one or both of the alignment film formed on the TFT substrate and the alignment film formed on the CF substrate. Next, a required amount of liquid crystal is dropped onto the main surface of the alignment film on one of the substrates. FIG. 9 shows a schematic cross-sectional view when two substrates are bonded together by a liquid crystal dropping method. In FIG. 9, the spacers and color filters other than the alignment films 4 and 8 are not shown. 9, the sealing material 31 is disposed on the main surface of the alignment film 8 formed on the CF substrate 5, and a necessary amount of the alignment film 4 formed on the opposite TFT substrate 1 is provided on the main surface. The liquid crystal 30 is dripped. In the bonding of the substrates, as shown by the arrow 50, the two substrates are brought close to each other and bonded and fixed while the main surfaces of the two substrates are kept parallel to each other. The bonding of the two substrates is performed in a reduced pressure atmosphere. The arrangement of the sealing material and the dropping of the liquid crystal after the alignment film is formed on the substrates are performed in an open atmosphere, and are performed in a reduced pressure atmosphere only when the substrates are bonded together.

  Since the alignment film is a porous substance, moisture is easily adsorbed on the surface. On the other hand, when moisture is mixed in the liquid crystal, the voltage holding ratio is lowered, and there is a problem that display unevenness or a stain occurs in the image. In order to prevent moisture from being mixed into the liquid crystal due to moisture adsorbed on the surface of the alignment film, the manufacturing process has a process of placing the substrate for a certain period of time in a reduced-pressure atmosphere called the degassing process. It has been. In order to perform the deaeration process, a vacuum chamber and a vacuum pump for decompressing the periphery of the entire substrate are required. In order to continue from the arrangement of the sealing material to the bonding of the substrates in a reduced pressure atmosphere, a very large facility is required. In the case where the deaeration process is performed before the sealing material is arranged, the substrate after the deaeration process is held in an open atmosphere from the arrangement of the sealing material to the bonding of the substrates. During this time, moisture in the atmosphere may be adsorbed again on the main surface of the alignment film. For this reason, the deaeration process is performed immediately before the bonding of the two substrates. The arrangement of other sealing materials, the dropping and transporting of liquid crystals, etc. are generally performed in an atmosphere open to the atmosphere.

  In JP-A-2003-107481, the amount of adsorbed moisture of the alignment film immediately before the arrangement of the sealing material is less than 4 wt%, and at least until the completion of the bonding after the formation of the alignment film, in an environment of less than 40% humidity. A method of manufacturing a liquid crystal display panel that performs each step is disclosed. In this manufacturing method, for example, after an alignment film is formed, storage and assembly are performed in an environment where the humidity is less than 40%, or storage and assembly are performed while purging dry air on the substrate. The step of disposing the sealing material on the surface of the substrate is performed in an atmosphere such as dry air, and the dropping of the liquid crystal and the bonding of the substrate are performed in a vacuum atmosphere. By this method, it is possible to prevent moisture from adsorbing to the alignment film during storage and assembly of the substrate, so that a liquid crystal display panel having no afterimage can be manufactured.

Japanese Patent Application Laid-Open No. 2001-305545 discloses a manufacturing method for preventing adsorption of moisture and an adsorbing gas on the alignment film surface by deactivating the alignment film surface immediately after the labyrinth treatment. In this method, the polarity of the alignment film surface is deactivated by performing a heat treatment at a temperature of 80 ° C. or more and less than 100 ° C. for a predetermined time immediately after the labyrinth process. By this method, it is possible to prevent moisture, adsorbing gas and the like from adsorbing on the alignment film surface, and to prevent various display unevenness.
JP 2003-107481 A (page 3-5, FIG. 2-5) JP 2001-305545 A (page 3-4)

  As described above, the deaeration process for placing the substrate in a reduced-pressure atmosphere is generally performed immediately before the substrates are bonded. FIG. 10 is a schematic enlarged cross-sectional view when a liquid crystal or a sealing material is disposed on the main surface of the alignment film in an open atmosphere. FIG. 10A is an enlarged cross-sectional view illustrating a state in which liquid crystal is dropped on the main surface of the alignment film. Since the alignment film is a porous substance, moisture in the atmosphere is adsorbed on the surface of the alignment film when left in the atmosphere. Before the substrates are bonded, a deaeration process is performed, and much of these moisture is evaporated. However, in the region where the liquid crystal 30 is dropped on the main surface of the alignment film 4, moisture does not evaporate because the main surface of the alignment film 4 is covered with the liquid crystal 30. As a result, the moisture adsorbed on the alignment film 4 remains as indicated by a broken line 40 in FIG. Similarly, for the sealing material, as shown in FIG. 10B, in the region where the sealing material 31 is disposed on the main surface of the alignment film 8, the moisture adsorbed on the alignment film 8 is broken. It remained as shown in FIG.

  FIG. 11 shows an explanatory diagram of a defect when a liquid crystal display panel is manufactured by bonding two substrates together with these moisture retained. FIG. 11 is a schematic plan view of the liquid crystal display panel 35. The sealing material 31 is formed in an annular shape, and liquid crystal is sealed inside a region surrounded by the sealing material 31. Of the region in which the liquid crystal is sealed, the image display unit 44 is a region where an image is displayed. In the liquid crystal display panel in which moisture remains in a part of the alignment film covered with the dropped liquid crystal and a part of the alignment film covered with the sealing material, defective display portions 45 and 46 are generated. The defective display portion 45 is a portion where the liquid crystal is dropped and a portion where a defect occurs around it, and the defective display portion 46 is a portion where a failure occurs around the seal material 31. The defective display portion 46 is caused by the moisture adsorbed on the alignment film being mixed into the liquid crystal through the sealing material 31. In these areas, there is a problem that spots and unevenness occur in the image, and in particular, a place that should be displayed in black becomes whitish. As described above, when moisture is mixed in the liquid crystal, there is a problem that the voltage holding ratio is lowered to cause display defects.

  In order to improve productivity with the aim of reducing the price, there is a manufacturing method in which a plurality of liquid crystal cells are formed on a mother substrate and then the substrate is cut into small portions for each liquid crystal cell so-called multi-chamfering. The number of cells on which the sealing material is arranged on the surface of the mother substrate reaches several hundreds per mother substrate. It is considered that the number of cells formed on one mother substrate will continue to increase. As the number of cells increases, the mother substrate tends to increase in size, and a substrate having a diagonal exceeding 1 meter is also used. When a large number of sealing materials are arranged on the surface of such a large mother substrate, it takes a long time, and moisture in the atmosphere released during this time is re-adsorbed. For this reason, even if the deaeration process is performed immediately before the arrangement of the sealing material, it is difficult to obtain a sufficient effect against the mixing of moisture into the liquid crystal.

  In the manufacturing method in Japanese Patent Application Laid-Open No. 2003-107481, the substrate is stored in an atmosphere of air with low humidity until the arrangement of the sealing material after the alignment film is formed, and stored in an atmosphere in which air is replaced with an inert gas. Or it must be stored in a reduced pressure atmosphere. Furthermore, it is necessary to subsequently arrange the sealing material in these atmospheres. For this reason, there is a problem that a large amount of equipment is required for storing the substrate and arranging the sealing material. Especially for large mother boards with diagonal lengths exceeding 1 meter, very expensive board storage equipment and sealing material placement equipment are required, which greatly reduces productivity. There was a problem of becoming expensive. Further, in the manufacturing method in which the substrate is stored and then subjected to heat treatment and release to the atmosphere, the alignment film is heated, so that the decomposition reaction inside the alignment film may proceed. In addition, there is a problem that the water once removed by the heat treatment is adsorbed to the alignment film again by opening to the atmosphere.

  In the manufacturing method disclosed in Japanese Patent Application Laid-Open No. 2001-305545, the alignment film is heated and then released into the atmosphere, so that there is a problem that the decomposition reaction of the alignment film accompanying the heating may proceed. In addition, there is a problem that moisture is adsorbed to the alignment film again because the atmosphere is released later.

  The present invention has been made to solve the above-described problems, and prevents liquid from entering the liquid crystal even on a large mother board, and further manufactures a liquid crystal display panel with high productivity. An object of the present invention is to provide a manufacturing method and a manufacturing apparatus capable of performing the above.

  In order to achieve the above object, a manufacturing method of a liquid crystal display panel according to the present invention includes a sealing material arrangement in which a sealing material is arranged on the main surface of one or both of two substrates to be bonded to each other. A method of manufacturing a liquid crystal display panel, comprising: a step; a liquid crystal dropping step of dropping liquid crystal on one of the two substrates; and a bonding step of bonding the two substrates together, Prior to the liquid crystal dropping step, at least the substrate to which the liquid crystal is to be dropped out of the two substrates is disposed in a reduced pressure atmosphere, and the reduced pressure atmosphere is inactivated before the bonding step. And an opening step of releasing with gas. By adopting this method, even for a large mother substrate, moisture can be prevented from adsorbing even if it is removed in advance from the substrate on which the liquid crystal is dropped and then placed in the atmosphere. A liquid crystal display panel in which defects are prevented can be manufactured. In addition, productivity is improved.

  In the above invention, preferably, the opening step is performed before the liquid crystal dropping step, and the liquid crystal dropping step is performed within 30 minutes after the opening step. By adopting this method, it is possible to reliably prevent the re-adsorption of the moisture and prevent the display defect.

  Preferably, in the above invention, the degassing step includes a step of arranging the two substrates together in the reduced pressure atmosphere. By adopting this method, it is possible to omit the deaeration process immediately before the above-described bonding process.

  In order to achieve the above object, an apparatus for manufacturing a liquid crystal display panel according to the present invention has a sealing material arrangement in which a sealing material is arranged on the main surface of one or both of two substrates to be bonded to each other. A manufacturing apparatus used in a method for manufacturing a liquid crystal display panel, comprising: a step, a liquid crystal dropping step of dropping liquid crystal on one of the two substrates, and a bonding step of bonding the two substrates together The apparatus includes a reduced pressure atmosphere forming unit for placing the substrate in the reduced pressure atmosphere, and an opening unit for opening the reduced pressure atmosphere with an inert gas. By adopting this configuration, it is possible to provide an apparatus for manufacturing a liquid crystal display panel that can remove moisture and prevent re-adsorption of moisture before bonding the two substrates.

  In the present invention, preferably, the reduced-pressure atmosphere forming means includes a vacuum chamber, a substrate placement member for placing a substrate in the vacuum chamber, and a vacuum pump for exhausting the inside of the vacuum chamber. The opening means includes an inert gas introduction means for introducing an inert gas into the vacuum chamber. By adopting this configuration, it is possible to easily form the liquid crystal display panel manufacturing apparatus.

  Preferably, in the above invention, the vacuum chamber is formed so as to accommodate two substrates to be bonded to each other. By adopting this configuration, the two substrates can be simultaneously accommodated in one vacuum chamber or the like, and the transition time to the bonding process can be shortened. Moreover, the work amount at the time of shifting to the bonding step is reduced, and the productivity is improved.

  Even for a large mother substrate, it is possible to provide a liquid crystal display panel manufacturing method and a manufacturing apparatus that prevent moisture from being mixed into the liquid crystal and further improve productivity.

(Embodiment 1)
(Production method)
A liquid crystal display panel manufacturing method and a liquid crystal display panel manufacturing apparatus according to Embodiment 1 of the present invention will be described with reference to FIGS.

  FIG. 1 is a process diagram of a method for manufacturing a liquid crystal display panel in the present embodiment. The manufactured liquid crystal display panel has the same configuration as the liquid crystal display panel based on the conventional technology. That is, as shown in FIG. 7, a scanning line driving circuit 2 for driving the TFT is formed on the main surface of the TFT substrate 1, and a TFT or the like is formed on the main surface of the scanning line driving circuit 2. A pixel electrode layer 3 is formed. An alignment film 4 is formed on the main surface of the pixel electrode layer 3. A color filter 6 is formed on the main surface of the CF substrate 5, and a counter electrode 7 is formed on the main surface of the color filter 6. An alignment film 8 is formed on the main surface of the counter electrode 7. The liquid crystal display panel has a configuration in which these two substrates are bonded to each other with a spacer 9 interposed therebetween. The two substrates are bonded and fixed by a sealing material 31, and the liquid crystal 30 is sealed in a space surrounded by the two substrates and the sealing material 31.

  In the manufacturing method according to the present invention, a sealing material arrangement in which an alignment film is formed on each of two substrates to be bonded to each other, and a sealing material is arranged on the main surface of one or both of these substrates It is the same as the manufacturing method based on the prior art that includes a step, a liquid crystal dropping step of dropping liquid crystal on one of the substrates, and a bonding step of bonding the two substrates together in a reduced-pressure atmosphere. .

In the method for manufacturing a liquid crystal display panel in this embodiment, before the sealing material arranging step, a deaeration step of arranging the substrate on which the alignment film is formed in a reduced pressure atmosphere, and the reduced pressure atmosphere are opened with an inert gas. Opening process. The sealing material arranging step is performed within about 30 minutes after the opening step is completed. After the alignment films are formed on the substrates, these substrates are placed in a reduced-pressure atmosphere to remove moisture contained in the surfaces of the alignment films. Thereafter, the reduced pressure atmosphere is opened with an inert gas such as N ₂ gas or Ar gas, so that these inert gases are adsorbed in the porous holes on the surface of the alignment film. For this reason, even if the substrate is taken out into the atmosphere, moisture can be prevented from being adsorbed to the alignment film. Therefore, moisture does not remain between the sealing material and the alignment film, and display defects that occur around the sealing material can be prevented.

  In this embodiment mode, liquid crystal is dropped on a substrate that is disposed on the opposite side of the substrate on which the sealing material is disposed. In this embodiment, the substrate on which the liquid crystal is dropped is also placed in a reduced-pressure atmosphere and then opened by introducing an inert gas. Since the inert gas is adsorbed on the surface of the alignment film, moisture adsorption can be prevented. As a result, moisture in the alignment film in the region where the liquid crystal is dropped can be removed, and display defects that occur in the region where the liquid crystal is dropped and the surrounding region can be prevented.

  The inert gas disposed in the porous holes of the alignment film instead of moisture diffuses into the atmosphere over time. For this reason, the concentration of the inert gas adsorbed on the alignment film decreases with time. For this reason, after the opening process, it is preferable to dispose the sealing material as soon as possible, and it is particularly preferable that the sealing process be performed within about 30 minutes after the opening process is completed. Similarly, the liquid crystal dropping step is preferably performed within about 30 minutes after opening the reduced-pressure atmosphere with an inert gas.

  After placing the two substrates to be bonded together in a reduced pressure atmosphere, the reduced pressure atmosphere is opened with an inert gas, so that either the substrate on which the sealing material is placed or the substrate on which the liquid crystal is dropped is placed. Regardless of whether it is a substrate or not, it is possible to prevent display defects due to the arrangement of the sealing material and the dropping of liquid crystal. At the same time, the moisture adsorbed on the alignment film and the like can be removed also in the region irrelevant to the arrangement of the sealing material and the dropping of the liquid crystal, and the time of being placed in the atmosphere after being opened with the inert gas. In the case of being short, it is not necessary to perform the deaeration process of placing the substrate in a reduced pressure atmosphere for a certain period of time immediately before the bonding of the substrates, and the bonding process can be performed immediately after the pressure reduction.

  In the manufacturing method according to the present invention, even when the alignment film is formed on the substrate and stored for a long time in the atmosphere, the substrate is placed in a reduced-pressure atmosphere immediately before the sealing material is placed or the liquid crystal is dropped. What is necessary is just to perform the open process which open | releases a gas process and a pressure-reduced atmosphere with inert gas. In the present invention, unlike the manufacturing method in which the atmosphere around the substrate is replaced (purged) with air or inert gas with reduced humidity as disclosed in the prior art, the substrate is once put in a vacuum atmosphere. After the water is sufficiently evaporated and removed, the inert gas is adsorbed on the surface of the alignment film. It is not necessary to store the substrate in an environment where management such as humidity is necessary unlike the manufacturing method disclosed in the prior art document, and after the alignment film is formed, it can be stored in normal air. As a result, the manufacturing equipment can be reduced in size, productivity can be improved, and a liquid crystal display panel can be manufactured at low cost.

  In addition, when bonding large substrates such as multiple substrates among various substrates, the equipment must be very large if it is stored in an atmosphere where humidity is controlled. There wasn't. However, in the manufacturing method in the present application, since a deaeration process and an opening process are performed immediately before the sealing material is arranged, a large facility for storage is unnecessary. As a result, even large substrates can be mass-produced with improved productivity.

  Further, since the arrangement of the sealing material and the dropping of the liquid crystal can be performed at atmospheric pressure, the arrangement of the sealing material and the dropping of the liquid crystal can be easily performed. Therefore, the progress of the work can be accelerated and the productivity is improved.

(manufacturing device)
2 to 4 are explanatory views of a liquid crystal display panel manufacturing apparatus according to the present invention. FIG. 2 is a partial schematic cross-sectional view of an apparatus for manufacturing a liquid crystal display panel according to the present invention. The manufacturing apparatus based on this invention is used for the manufacturing method of a liquid crystal display panel including the sealing material arrangement | positioning process, a liquid crystal dropping process, and the bonding process which bonds two board | substrates together. That is, it is a manufacturing apparatus used for the liquid crystal dropping method.

  An apparatus for manufacturing a liquid crystal display panel according to the present invention includes a reduced-pressure atmosphere forming means for disposing a substrate in a reduced-pressure atmosphere and an opening means for releasing the reduced-pressure atmosphere with an inert gas. Two substrates such as the TFT substrate 1 on which the alignment film is formed and the CF substrate 5 on which the alignment film is formed are disposed inside the vacuum chamber 20. The vacuum chamber 20 is made of aluminum, but may be made of stainless steel or the like. The vacuum chamber 20 in the present embodiment is formed so as to accommodate two substrates to be bonded to each other. The vacuum chamber 20 is formed so that the inside is a cavity and can be kept sealed from the outside. Inside the vacuum chamber 20, two support bases 21 are formed as substrate placement members so as to face each other. The support base 21 is formed so that two substrates to be bonded to each other can be arranged one above the other. The support 21 is fixed to the bottom of the vacuum chamber 20.

  A vacuum exhaust means 16 for exhausting the inside of the vacuum chamber 20 is connected to the vacuum chamber 20. The vacuum exhaust means 16 includes an exhaust pipe 17, an exhaust valve 18 and a vacuum pump 19. In the present embodiment, the vacuum evacuation means 16, the vacuum chamber 20, and the support base 21 formed inside the vacuum chamber 20 constitute a reduced pressure atmosphere forming means for placing the substrate in the reduced pressure atmosphere. .

An inert gas introducing means 11 is connected to the vacuum chamber 20 as an opening means. The inert gas introduction means 11 includes an air supply pipe 12, an air supply valve 13, and a cylinder 14. The inside of the cylinder 14 is filled with an inert gas such as N ₂ or Ar.

  FIG. 3 shows a cross-sectional view of the vacuum chamber taken along line III-III in FIG. The vacuum chamber 20 is formed in a substantially rectangular parallelepiped shape. The two substrates, the TFT substrate 1 and the CF substrate 5, are arranged on the support base 21 so that the main surface is horizontal. An opening / closing door 22 is formed in front of the vacuum chamber 20 so as to correspond to each stage of the support base 21 formed in two stages. The open / close door 22 is formed so as to be openable and closable, and is sufficiently large so that each substrate can be taken in and out. Moreover, when the opening / closing door 22 is closed, it is formed so that the inside can be kept airtight.

  FIG. 4 shows a schematic overall view of the manufacturing apparatus in the present embodiment. A plurality of the same manufacturing apparatuses including the inert gas introduction unit 11, the vacuum exhaust unit 16, and the vacuum chamber 20 are formed and disposed inside the vacuum chamber 25. Each vacuum chamber 20 is connected to the respective inert gas introducing means 11 and vacuum evacuating means 16 and is formed so that internal exhaust and introduction of inert gas can be performed independently of each other. Further, the support base 21 shown in FIG. 3 is formed in each vacuum chamber 20 so as to accommodate two substrates to be bonded to each other.

  This apparatus is used for, for example, a deaeration process in which the substrate is placed in a reduced pressure atmosphere and an open process in which the reduced pressure atmosphere is opened with an inert gas after the alignment film is formed in the manufacturing method of FIG. First, the opening / closing door 22 is opened, and the TFT substrate 1 and the CF substrate 5 are arranged on each stage of the support base 21 inside the vacuum chamber 20. Each substrate is disposed so as to be completely contained in the vacuum chamber 20. In the present embodiment, the TFT substrate 1 is disposed on the upper side and the CF substrate 5 is disposed on the lower side. However, the present invention is not limited to this arrangement, and either substrate may be on the upper side. Further, in order to mainly evaporate moisture in the formed alignment film, it is preferable to arrange the alignment film on the upper side so that the alignment film does not come into contact with the support base 21. When the arrangement of each substrate is completed, all the open / close doors 22 (see FIG. 3) are closed to seal the vacuum chamber 20.

  Next, the vacuum pump 19 is driven, the exhaust valve 18 is opened, and the inside of the vacuum chamber 20 is exhausted. The inside of the vacuum chamber 20 is evacuated to about 30 Pa. Since the alignment film may be damaged if the pressure inside the vacuum chamber 20 is suddenly lowered, it is preferable that the pressure inside the vacuum chamber 20 is gradually lowered. Therefore, the exhaust valve 18 is preferably a valve that can gradually change the opening degree. As the exhaust valve 18 in the present embodiment, a valve that can continuously increase the valve opening and that can gradually increase the valve opening is used. The pressure is reduced to about 30 Pa, and this low pressure is maintained for about 30 minutes to evaporate moisture on the surface of the alignment film. Thus, a deaeration process is performed.

  The time for maintaining the pressure in the vacuum chamber and the reduced pressure state is not particularly limited to this. For example, depending on the type of the alignment film, the pressure in the vacuum chamber may be reduced to 1 Pa or less. In other words, it is preferable to change the conditions of the deaeration process performed under reduced pressure according to the type of the alignment film formed.

  When the deaeration process is completed, the exhaust valve 18 is closed and the air supply valve 13 is opened, and the inert gas is introduced into the vacuum chamber 20 from the inert gas introduction means 11. That is, an opening process is performed. As the air supply valve 13 in the present embodiment, a valve capable of adjusting the opening degree so that the pressure inside the vacuum chamber 20 can be gradually increased is used. The introduction of the inert gas is continued until the pressure inside the vacuum chamber 20 reaches atmospheric pressure. When the pressure inside the vacuum chamber 20 rises to atmospheric pressure, the supply valve 13 is closed and the introduction of the inert gas is stopped. In this state, each substrate is stored in the vacuum chamber 20 until the sealing material arranging step. Alternatively, when the time to the sealing material arranging step is within about 30 minutes, each substrate may be taken out from the inside of the vacuum chamber 20 and stored.

  In the manufacturing apparatus used for the liquid crystal dropping method, a reduced pressure atmosphere forming means and an opening means for releasing the reduced pressure atmosphere with an inert gas are provided, thereby forming an alignment film formed on the main surface of each substrate and the main surface of the substrate. The moisture can be replaced with an inert gas, and the moisture can be prevented from being re-adsorbed even when the substrate is subsequently placed in the atmosphere. As a result, display defects of the liquid crystal display panel can be prevented. In addition, it is not necessary to continuously control the humidity from the formation of the alignment film to the pasting, and it can be stored in the atmosphere after the formation of the alignment film and immediately before the placement of the sealing material or the dropping of the liquid crystal. The equipment can be very simple. Even large substrates can be processed easily, improving productivity.

  Further, by forming the vacuum chamber so as to accommodate two substrates to be bonded to each other, the two substrates can be processed at the same time, and the waiting time until the processing of one substrate is completed, That is, the lead time until the next process can be minimized, and the productivity is improved.

  As shown in FIG. 4, a large number of small vacuum chambers 20 are formed so that each vacuum chamber can independently supply exhaust gas and supply of inert gas. Each substrate can be placed in an inert gas atmosphere until just before or, if necessary, just before the liquid crystal dropping step, and moisture adsorption can be prevented more reliably. Further, each substrate can be inserted into the manufacturing apparatus in which the removal of each substrate has been completed, and the deaeration process and the release process can be performed, and each substrate can be processed continuously. Therefore, the waiting time in the manufacturing process can be minimized, productivity can be improved, and an inexpensive liquid crystal display panel can be provided.

  In the manufacturing apparatus according to the present embodiment, two substrates are arranged in the vacuum chamber. However, the present invention is not limited to this, and one substrate or three or more substrates are provided in one vacuum chamber. These substrates may be formed so that they can be arranged. In this embodiment, one vacuum pump is attached to each vacuum chamber, but a plurality of exhaust pipes are connected to a large vacuum pump, and the pressure inside each vacuum chamber is However, it may be adjusted by each exhaust valve. Also, the inert gas introduction means may have a configuration in which the inert gas is introduced into the vacuum chamber, such as a plurality of supply pipes connected to many parallel cylinders.

(Embodiment 2)
With reference to FIG. 5, the manufacturing method and manufacturing apparatus of the liquid crystal display panel in Embodiment 2 based on this invention are demonstrated.

  In the present embodiment, an alignment film is formed on the surface of the substrate, and liquid crystal is sealed by a liquid crystal dropping method, as in the manufacturing method in the first embodiment. As in the first embodiment, the substrate on which the alignment film is formed is placed in a reduced-pressure atmosphere and later released with an inert gas.

  In addition to the configuration of the manufacturing apparatus in the first embodiment, the liquid crystal display panel manufacturing apparatus in the present embodiment includes a dispenser for disposing a sealing material inside the vacuum chamber, and the sealing material inside the vacuum chamber. It is formed so that it can be arranged.

  In the manufacturing method in the present embodiment, the sealing material arranging step of arranging the sealing material on the main surface of one or both of the two substrates to be bonded to each other is performed in a reduced pressure atmosphere. After depressurizing the atmosphere in which each substrate is placed, this pressure is maintained for a predetermined time to evaporate moisture on the surface and inside of the alignment film. Next, a sealing material is disposed on one or both of the substrates under the reduced pressure atmosphere.

When the arrangement of the sealing material is completed, an inert gas such as N ₂ gas or Ar gas is introduced into the vacuum chamber, the inside of the vacuum chamber is brought to atmospheric pressure, and the substrate is stored in the vacuum chamber. . Immediately before the liquid crystal dropping step of dropping the liquid crystal on one of the substrates, the substrate is taken out from the vacuum chamber. Alternatively, if the time until the liquid crystal dropping step is short, it may be taken out and stored in the atmosphere. Next, after performing a liquid crystal dropping process, a bonding process is performed.

  In the method for manufacturing a liquid crystal display panel in the present embodiment, the sealing material is disposed in a state where the substrate is disposed in a reduced pressure atmosphere. That is, the sealing material is disposed on the upper surface of the alignment film from which moisture has been sufficiently removed. By adopting this method, it is possible to prevent moisture from being held in the alignment film in the region where the sealing material is disposed, and display defects around the region where the sealing material is disposed can be prevented. Further, by opening the reduced pressure atmosphere in the vacuum chamber with an inert gas, it is possible to prevent water from being mixed when the liquid crystal is dropped.

  If the substrate on which the liquid crystal is dropped is different from the substrate on which the sealing material is placed, the substrate on which the liquid crystal is dropped is also placed in a vacuum atmosphere in the vacuum chamber in advance and then in the vacuum chamber with an inert gas. An opening process for opening is performed. By adopting this method, the moisture in the alignment film can be removed in advance even on the substrate onto which the liquid crystal is dropped, and display defects in the region where the liquid crystal is dropped can be prevented. The dropping of the liquid crystal is preferably performed within about 30 minutes after releasing the reduced-pressure atmosphere with an inert gas, as in the first embodiment. By adopting this method, display defects can be reliably prevented even when the liquid crystal dropping step is performed in a normal atmosphere. Therefore, the liquid crystal dropping device can have a simple structure, and the work can be easily performed, so that productivity is improved.

  Further, even when the sealing material is disposed on the substrate on which the liquid crystal is dropped, it is preferable to perform the deaeration step and the opening step on the opposite substrate before the bonding step. By adopting this method, it is not necessary to perform a deaeration process immediately before the bonding process, and the manufacturing time is shortened and the productivity is improved.

  In the liquid crystal display panel manufacturing apparatus according to the first embodiment, the liquid crystal display panel is formed so as to accommodate two substrates to be bonded to each other. However, in the present embodiment, the substrate on which the sealing material is disposed and the liquid crystal In the case where the same substrate is dropped, only one substrate may be disposed in the vacuum chamber so that only this substrate can be processed.

  Since other manufacturing methods and manufacturing apparatuses are the same as those in the first embodiment, description thereof will not be repeated here.

(Embodiment 3)
With reference to FIG. 6, the manufacturing method and manufacturing apparatus of the liquid crystal display panel in Embodiment 3 based on this invention are demonstrated.

  In the present embodiment, an alignment film is formed on the surface of the substrate, and liquid crystal is sealed by a liquid crystal dropping method, as in the manufacturing method in the first embodiment. As in the first embodiment, the substrate on which the alignment film is formed is placed in a reduced-pressure atmosphere and later released with an inert gas.

  In the present embodiment, the sealing material arranging step and the liquid crystal dropping step are performed in a reduced pressure atmosphere. Thereafter, the reduced pressure atmosphere in the vacuum chamber is opened with an inert gas, and each substrate is stored inside the vacuum chamber until the substrate bonding step.

  In addition to the internal configuration of the vacuum chamber in the first embodiment, a dispenser for disposing a sealing material and a dispenser for dropping liquid crystal are disposed inside the vacuum chamber in the present embodiment. The arrangement of the sealing material and the dropping of the liquid crystal may be performed on any substrate. Moreover, you may perform arrangement | positioning of a sealing material with respect to both board | substrates.

  By adopting this manufacturing method, since the sealing material is placed and the liquid crystal is dropped while the moisture is sufficiently removed from the surface of the alignment film, the moisture can be removed, and the liquid can be mixed into the liquid crystal. Can be prevented. As a result, it is possible to more reliably prevent display defects occurring around the area where the sealing material is disposed, the area where the liquid crystal is dropped, and the area where the liquid crystal is dropped. In addition, the reduced-pressure atmosphere in the vacuum chamber can be opened with an inert gas and stored until just before the substrates are bonded, so that moisture can be prevented from adsorbing to the substrate and the alignment film during this time, and the liquid crystal display It is possible to prevent display failure of the panel. If the time to store the substrate in the atmosphere after the opening process is short, moisture can be prevented from adsorbing to the substrate, and the deaeration process immediately before the bonding process can be omitted, reducing the manufacturing time. can do.

  Since other manufacturing methods and manufacturing apparatuses are the same as those in the first embodiment, description thereof will not be repeated here.

  In the above embodiment, the case where the degassing step is mainly performed before the sealing material arranging step has been described. However, in the case where only the mixing of moisture related to the liquid crystal dropping step is prevented, the sealing material arranging step is performed. Do not perform a degassing step or the like on the substrate on which the sealing material is disposed before, but perform a degassing step before the liquid crystal dropping step and an opening step before the bonding step only on the substrate on which the liquid crystal is dropped. Also good.

  In the above-described embodiment, the description has been made mainly with the color liquid crystal display panel. However, the present invention is not limited to the color liquid crystal, and can be applied to a monochrome liquid crystal display panel.

  In addition, the said embodiment disclosed this time is an illustration in all the points, Comprising: It is not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and includes all modifications within the scope and meaning equivalent to the terms of the claims.

FIG. 3 is a process diagram of the manufacturing method in the first embodiment. 2 is a schematic cross-sectional view of the manufacturing apparatus according to Embodiment 1. FIG. 2 is a schematic cross-sectional view of a vacuum chamber in the manufacturing apparatus according to Embodiment 1. FIG. 1 is a schematic overall view of a manufacturing apparatus in Embodiment 1. FIG. FIG. 10 is a process diagram of the manufacturing method in the second embodiment. FIG. 10 is a process diagram of the manufacturing method in the third embodiment. It is a schematic sectional drawing of a color liquid crystal display panel. It is process drawing of the manufacturing method of the liquid crystal display panel based on a prior art. It is a schematic sectional drawing explaining a liquid crystal dropping system. (A) And (b) is explanatory drawing of the malfunction of the manufacturing method in a prior art. It is a schematic plan view explaining the malfunction of the liquid crystal display panel in a prior art.

Explanation of symbols

  1 TFT substrate, 2 scanning line driving circuit, 3 pixel electrode layer, 4,8 alignment film, 5 CF substrate, 6 color filter, 7 counter electrode, 9 spacer, 11 inert gas introduction means, 12 air supply pipe, 13 air supply Valve, 14 cylinder, 16 vacuum exhaust means, 17 exhaust pipe, 18 exhaust valve, 19 vacuum pump, 20 vacuum chamber, 21 support base, 22 open / close door, 25 vacuum tank, 30 liquid crystal, 31 sealing material, 35 liquid crystal display panel, 40, 41 Broken line, 44 Image display part, 45, 46 Display failure part, 50 arrows.

Claims (6)

A sealing material disposing step of disposing a sealing material on the main surface of one or both of the two substrates to be bonded to each other;
A liquid crystal dropping step of dropping a liquid crystal on one of the two substrates;
A method of manufacturing a liquid crystal display panel, comprising a bonding step of bonding the two substrates to each other,
Before the liquid crystal dropping step, a deaeration step of disposing at least a substrate to which the liquid crystal should be dropped out of the two substrates in a reduced pressure atmosphere;
The manufacturing method of a liquid crystal display panel including the opening process of opening the said decompression atmosphere with an inert gas before the said bonding process. Performing the opening step before the liquid crystal dropping step,
The liquid crystal display panel manufacturing method according to claim 1, wherein the liquid crystal dropping step is performed within 30 minutes after the opening step.   The method of manufacturing a liquid crystal display panel according to claim 1, wherein the degassing step includes a step of arranging the two substrates together in the reduced-pressure atmosphere. A sealing material disposing step of disposing a sealing material on the main surface of one or both of the two substrates to be bonded to each other;
A liquid crystal dropping step of dropping a liquid crystal on one of the two substrates;
A manufacturing apparatus for use in a method for manufacturing a liquid crystal display panel, comprising a bonding step of bonding the two substrates together;
Reduced pressure atmosphere forming means for placing the substrate in the reduced pressure atmosphere;
An apparatus for manufacturing a liquid crystal display panel, comprising: opening means for opening the reduced-pressure atmosphere with an inert gas. The reduced-pressure atmosphere forming means includes a vacuum chamber,
A substrate placement member for placing a substrate in the vacuum chamber;
A vacuum pump for evacuating the inside of the vacuum chamber, the opening means,
The apparatus for manufacturing a liquid crystal display panel according to claim 4, further comprising an inert gas introduction unit for introducing an inert gas into the vacuum chamber.   The liquid crystal display panel manufacturing apparatus according to claim 5, wherein the vacuum chamber is formed so as to accommodate two substrates to be bonded to each other.

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