JP2009265639A - Method of manufacturing liquid crystal display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a liquid crystal display, for manufacturing a high-quality liquid crystal display by properly arranging spacer particles. <P>SOLUTION: The method of the manufacturing liquid crystal display includes: a spacer region forming step (S1) of forming a spacer region containing spacer particles by jetting a spacer particle dispersion liquid wherein spacer particles are dispersed over a transparent substrate by an inkjet system, a drying step (S3) of heating the transparent substrate where the spacer region is formed to vaporize a volatile component of the spacer particle dispersion liquid and fix the spacer particles in the spacer region on the transparent substrate, and a cleaning and removing step of cleaning the transparent substrate where the spacer particles are fixed with a liquid to remove spacer particles which are not in the spacer region. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a liquid crystal display device in which a gap for enclosing a liquid crystal layer is formed by interposing spacer particles between substrates.

  The liquid crystal display device has a configuration in which a transparent electrode, a color filter, and a black matrix are disposed between two substrates, and liquid crystal is sealed in a space between the transparent electrodes. At this time, a spacer is formed in order to regulate the distance between the two substrates and make the thickness of the liquid crystal layer appropriate.

  Conventionally, this spacer has been formed by using a photolithographic method. However, there is a problem that a process using a mask is required and the work process is complicated, and the use efficiency of the material is poor. For this reason, a method of manufacturing a liquid crystal display device in which spacers are formed with spacer particles by discharging a spacer particle dispersion liquid in which spacer particles are dispersed by an inkjet method on a substrate has been proposed (see Patent Document 1).

JP 2005-4094 A

  When liquid is ejected by the ink jet method, minute droplets separated from main droplets called satellites are generated. In the ink jet system, since the liquid is ejected while relatively moving the ink jet nozzle and the substrate, a droplet called a satellite is dropped at a position different from the main droplet.

  For this reason, when the spacer particle dispersion liquid in which the spacer particles are dispersed is discharged by the ink jet head, the spacer particles may be present in the satellite dripped in the region other than the spacer region to be the spacer. If such spacer particles are present in the color filter portion of the liquid crystal display device, the liquid crystal molecules in that portion cannot perform normal alignment operation, which causes quality deterioration such as light leakage and light leakage.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a method of manufacturing a liquid crystal display device capable of manufacturing a high-quality liquid crystal display device by appropriately arranging spacer particles. And

  The invention according to claim 1 is a method of manufacturing a liquid crystal display device in which a gap for enclosing a liquid crystal layer is formed by interposing spacer particles between substrates, and the spacer particles are dispersed on the substrate by an ink jet method. A spacer region forming step of forming a spacer region containing spacer particles by discharging the spacer particle dispersion, and evaporating volatile components from the spacer particle dispersion by drying the substrate on which the spacer region is formed, A drying step of fixing the spacer particles and the substrate in the spacer region, and a cleaning and removing step of removing the spacer particles existing outside the spacer region by cleaning the substrate to which the spacer particles are fixed with a liquid. Features.

  According to a second aspect of the present invention, in the first aspect of the invention, in the cleaning and removing step, most of the spacer particles in the spacer region are not removed from the substrate, but are present outside the spacer region. The spacer particles are ejected to the surface of the substrate with a liquid having a pressure enough to be removed.

  According to a third aspect of the present invention, in the second aspect of the present invention, the liquid is pure water, and in the cleaning and removing step, high-pressure pure water is applied toward the substrate while the substrate is conveyed in the horizontal direction. Erupts.

  According to a fourth aspect of the present invention, in the second aspect of the present invention, the liquid is obtained by mixing a gas in pure water. In the cleaning and removing step, the substrate is conveyed while being transported in the horizontal direction. High-pressure pure water mixed with gas is spouted toward

  The invention according to claim 5 is the invention according to any one of claims 2 to 4, wherein the drying step includes a pre-bake step of heating the substrate at a first temperature, and the substrate at the first temperature. And a post-baking step of heating at a higher second temperature.

  According to a sixth aspect of the present invention, in the invention according to any one of the second to fifth aspects, after the drying step is completed, a larger amount of the spacer dispersion is discharged than is necessary in the spacer region forming step. A larger amount of spacer particles than the necessary amount are fixed to the substrate, and excess spacer particles exceeding the necessary amount are removed together with the spacer particles existing outside the spacer region in the cleaning and removing step.

  According to the first and second aspects of the invention, the spacer particles can be properly arranged, and a high-quality liquid crystal display device can be manufactured.

  According to the third aspect of the present invention, it is possible to satisfactorily remove the spacer particles existing outside the spacer region while leaving most of the spacer particles in the spacer region with high-pressure pure water.

  According to the fourth aspect of the present invention, the pure water mixed with the high-pressure gas can satisfactorily remove the spacer particles existing outside the spacer region while leaving most of the spacer particles in the spacer region. It becomes possible.

  According to the fifth aspect of the present invention, it is possible to sufficiently fix the spacer particles and the substrate after the spacer particles are sufficiently condensed by evaporating the volatile component from the spacer particle dispersion.

  According to the invention described in claim 6, when removing the spacer particles existing outside the spacer region, extra spacer particles exceeding the necessary amount existing in the spacer region together with the spacer particles existing outside the spacer region are present. Even if removed, a necessary amount of spacer particles can be secured in the spacer region.

3 is a flowchart showing a method for manufacturing a liquid crystal display device according to the present invention. It is a partial surface view which shows a part of transparent substrate 1 after spacer particle dispersion liquid is discharged to the surface. It is a schematic diagram which shows the state which wash | cleans the transparent substrate 1 with a washing | cleaning apparatus. It is a top view which shows the state which wash | cleans the transparent substrate 1 with a washing | cleaning apparatus. It is explanatory drawing which shows the distance H1 of the pure water discharge nozzle 3 and the transparent substrate 1. FIG. It is a schematic diagram which shows the state which wash | cleans the transparent substrate 1 in 2nd Embodiment of this invention with a washing | cleaning apparatus. It is a top view which shows the state which wash | cleans the transparent substrate 1 with a washing | cleaning apparatus in 2nd Embodiment of this invention. It is a schematic diagram of the spray pipe 2 provided with the two-fluid nozzle 8. FIG. It is the perspective view which fractured | ruptured a part of two fluid nozzle 8. FIG. It is explanatory drawing which shows the distance H2 of the two-fluid nozzle 8 and the transparent substrate 1. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a flowchart showing a method for manufacturing a liquid crystal display device according to the present invention.

  This method of manufacturing a liquid crystal display device is executed as a pre-process such as a liquid crystal encapsulation process, and is for forming a gap for encapsulating a liquid crystal layer by interposing spacer particles between transparent substrates. .

  When the method for manufacturing a liquid crystal display device according to the present invention is executed, first, a spacer region generation step is executed (step S1). In this spacer region generating step, a spacer region containing spacer particles is formed by discharging a spacer particle dispersion liquid in which spacer particles are dispersed by an inkjet method on a transparent substrate. In this case, an ink jet type image recording apparatus is used in which a spacer particle dispersion is discharged onto the surface of a transparent substrate by moving an ink jet head in which a large number of ink jet nozzles are arranged relative to the transparent substrate.

  FIG. 2 is a partial surface view showing a part of the transparent substrate 1 after the spacer particle dispersion is discharged onto the surface.

  On the surface of the transparent substrate 1, there are a red color filter region R, a green color filter region G, a blue color filter region B, and a black matrix 7 region defining these regions. Composed. Then, the spacer particle dispersion is discharged toward the region of the black matrix 7 to form the spacer region 5 there.

  At this time, when the spacer particle dispersion is ejected by the ink jet method, extremely small droplets separated from main droplets called satellites are generated. Then, since the spacer particle dispersion is discharged while relatively moving the ink jet nozzle and the transparent substrate, a droplet called a satellite is dropped at a position different from the main droplet. When spacer particles are present in this droplet, the spacer particles 6 separated from the spacer region 5 are present on the transparent substrate 1 as shown in the enlarged view of FIG. When such spacer particles 6 are present in the color filter region, the liquid crystal molecules in that portion cannot perform normal alignment operation, which causes a deterioration in quality such as light leakage and light leakage. For this reason, in the present invention, the spacer particles 6 are removed in the subsequent cleaning step.

  Referring to FIG. 1 again, a drying process is executed following the spacer region generation process (step S2). In this drying step, the transparent substrate 1 is transported to a hot plate, and the transparent substrate 1 is heated to about 100 degrees Celsius to about 200 degrees Celsius on the hot plate, thereby evaporating volatile components from the spacer particle dispersion. In this step, the spacer particles in the spacer region 5 are fixed to the transparent substrate 1.

  In this step, since the volatile components are first evaporated from the spacer particle dispersion, the spacer particles in the spacer region 5 gather together and come into contact with each other due to surface tension. Then, they are baked and fixed to each other, and are also fixed to the surface of the transparent substrate 1 with a strong force. At this time, since the spacer particles existing outside the spacer region 5 are single and exist there, they are fixed to the surface of the transparent substrate 1 but are not fixed with a strong force.

  In addition, it is preferable that this drying process is comprised from the prebaking process which heats a board | substrate at 1st temperature, and the post-baking process which heats a board | substrate at 2nd temperature higher than said 1st temperature. With such a configuration, it is possible to sufficiently fix the spacer particles and the substrate after the spacer particles are sufficiently condensed by evaporating the volatile component from the spacer particle dispersion.

  When the drying process is completed, a cleaning removal process is executed (step S3). This washing and removing step is a step of removing the spacer particles 6 other than the spacer region 5 by transporting the transparent substrate 1 to the washing device and washing the dried and baked transparent substrate 1 with high-pressure pure water. .

  FIG. 3 is a schematic view showing a state in which the transparent substrate 1 is cleaned by a cleaning apparatus, and FIG. 4 is a plan view thereof. FIG. 5 is an explanatory diagram showing the distance H1 between the pure water discharge nozzle 3 and the transparent substrate 1. FIG.

  The transparent substrate 1 after drying and firing is transported in the direction of the arrow shown in FIGS. 3 and 4 by a plurality of transport rollers 4. Then, high-pressure pure water is ejected from the spray pipe 2 provided with a plurality of pure water discharge nozzles 3 disposed above the transparent substrate 1 onto the surface of the transparent substrate 1 being conveyed. In FIG. 4, the position of the pure water discharge nozzle 3 is schematically shown, but the pure water discharge nozzle 3 is disposed on the lower surface of the spray pipe 2.

  At this time, the pressure of the pure water discharged to the transparent substrate 1 is such that most of the spacer particles in the spacer region 5 shown in FIG. 2 are not removed, but the spacer particles 6 other than the spacer region 5 are removed. It is. That is, in the spacer region 5, the spacer particles firmly adhere to each other in the drying process, and also adhere to the surface of the transparent substrate 1 with a strong force. On the other hand, the spacer particles 6 other than the spacer region 5 are fixed to the surface of the transparent substrate 1 but are not fixed with a strong force. For this reason, the pressure of pure water discharged to the transparent substrate 1, the transport speed of the transparent substrate 1, the distance H1 between the surface of the transparent substrate 1 and the pure water discharge nozzle 3 shown in FIG. Thus, it is possible to selectively remove the spacer particles 6 that exist outside the spacer region 5.

  Actually, for example, while transporting the transparent substrate 1 at a speed of 3 mm per second, the distance H1 between the surface of the transparent substrate 1 and the pure water discharge nozzle 3 is set to 50 mm, and the pressure from the pure water discharge nozzle 3 is 5 MPa (megapascals). ), The spacer particles 6 other than the spacer region 5 can be removed without removing most of the spacer particles in the spacer region 5.

  Further, according to another experiment, the transport speed of the transparent substrate 1 is preferably used as a condition for suitably removing the spacer particles 6 other than the spacer region 5 without removing most of the spacer particles in the spacer region 5. Is preferably 50 cm to 300 cm per minute, the pressure of pure water is preferably 2.5 MPa to 10.0 MPa, and the distance H1 between the surface of the transparent substrate 1 and the pure water discharge nozzle 3 is 15 mm to 60 mm. It has been confirmed that this is preferable.

  In the spacer region generation step described above, a larger amount of spacer dispersion is discharged to the spacer region 5 than necessary to fix a larger amount of spacer particles to the substrate after the drying step. Yes. Then, a larger amount of spacer particles than are necessary in the washing and removing process are removed together with the spacer particles 6 that exist outside the spacer region 5.

  In the washing and removing process, a part of the spacer particles in the spacer region 5 is also removed, but the spacer particles to be removed are often spacer particles arranged on the outermost side of the spacer region 5. For this reason, the area occupied by the spacer particles is required when the spacer particles are condensed by evaporating volatile components from the spacer particle dispersion after discharging a larger amount of spacer dispersion than necessary to the spacer region 5. Keep the area larger. When the washing and removing process is executed in such a state, the spacer particles arranged on the outermost side of the spacer region 5 are also removed together with the spacer particles 6 other than the spacer region 5. Therefore, a necessary amount of spacer particles can be secured in the spacer region.

  When the above steps are completed, spacer particles exist only in the spacer region 5 on the transparent substrate 1. For this reason, it becomes possible to arrange | position spacer particle | grains appropriately. Subsequently, by successively executing the manufacturing process of the liquid crystal display device successively, it becomes possible to manufacture a high quality liquid crystal display device.

  Next, another embodiment of the present invention will be described. FIG. 6 is a schematic view showing a state in which the transparent substrate 1 is cleaned by a cleaning apparatus in the second embodiment of the present invention, and FIG. 7 is a plan view thereof.

  In the embodiment described above, high-pressure pure water is jetted onto the surface of the transparent substrate 1 to clean and remove the spacer particles 6 that exist outside the spacer region 5. On the other hand, in the second embodiment, a two-fluid nozzle 8 that forms a fluid in which gas and pure water are mixed is used, and a fluid in which high-pressure gas and high-pressure pure water are mixed, The transparent substrate 1 is cleaned and removed.

  The transparent substrate 1 after drying and baking is conveyed in the direction of the arrow shown in FIGS. And from the spray pipe 2 provided with the several 2 fluid nozzle 8 arrange | positioned above the transparent substrate 1, the high pressure pure water which mixed the high pressure gas on the surface of the transparent substrate 1 in conveyance is ejected. . In FIG. 7, the position of the two-fluid nozzle 8 is schematically shown, but the two-fluid nozzle 8 is disposed on the lower surface of the spray pipe 2.

  FIG. 8 is a schematic view of the spray pipe 2 provided with the two-fluid nozzle 8, and FIG. 9 is a perspective view in which a part of the two-fluid nozzle 8 is broken. Further, FIG. 10 is an explanatory diagram showing a distance H2 between the two-fluid nozzle 8 and the transparent substrate 1. FIG.

  As shown in FIG. 8, 16 two-fluid nozzles 8 are arranged on the spray pipe 2 so as to face downward. The spray pipe 2 is provided with a gas inflow pipe 85 and a pure water inflow pipe 86. As shown in FIG. 9, the two-fluid nozzle 8 has a configuration in which the gas supplied from the inflow pipe 85 and the pure water supplied from the inflow pipe 86 are mixed and discharged from the discharge port 84.

  The pressure of pure water mixed with the gas discharged from the two-fluid nozzle 8 to the transparent substrate 1 does not remove most of the spacer particles in the spacer region 5 shown in FIG. 2 as in the above-described embodiment. The spacer particles 6 other than the spacer region 5 are at such a pressure that they are removed.

  Actually, for example, while transporting the transparent substrate 1 at a speed of 200 cm per minute, the distance H2 between the surface of the transparent substrate 1 and the two-fluid nozzle 8 is set to 50 mm, and the pressure from the two-fluid nozzle 8 is 0.4 MPa. When the transparent substrate 1 was observed after repeating the operation of ejecting a mixture of water and air having a pressure of 0.4 MPa twice, the probability that the spacer particles 6 other than the spacer region 5 were removed was 51. The probability that the spacer particles in the spacer region 5 remain without being removed was 99.2%.

  Further, when the transport speed of the transparent substrate 1 is set to 100 cm / min under the same conditions, the probability that the spacer particles 6 other than the spacer region 5 are removed is 79.0%. The probability that the spacer particles remained without being removed was 95.4%.

  Further, according to another experiment, the transport speed of the transparent substrate 1 is preferably used as a condition for suitably removing the spacer particles 6 other than the spacer region 5 without removing most of the spacer particles in the spacer region 5. Is preferably 50 cm to 300 cm per minute, the pressure of pure water and gas is preferably 0.1 MPa to 1.0 MPa, and the distance H1 between the surface of the transparent substrate 1 and the pure water discharge nozzle 3 is 15 mm to It has been confirmed that the thickness is preferably 60 mm.

  In the embodiment described above, in the cleaning and removing step of removing the spacer particles 6 other than the spacer regions 5 by cleaning the substrate with pure water, the spacer particles in the spacer regions 5 are removed from the transparent substrate 1. Most of the spacer particles 6 that are not removed but are present outside the spacer region 5 are discharged onto the surface of the transparent substrate 1 with pure water at a pressure sufficient to remove the spacer particles 6. However, the present invention is not limited to such a form.

  That is, the transparent substrate 1 may be cleaned and removed using a microbubble cleaning solution in which a fine gas is dissolved in pure water. It is also possible to clean and remove the transparent substrate 1 with pure water to which ultrasonic vibration is applied. Furthermore, a liquid such as a chemical solution other than pure water may be used.

  Furthermore, in the drying process in the above-described embodiment, the transparent substrate 1 is transported to a hot plate and heated to evaporate volatile components from the spacer particle dispersion and to fix the spacer particles in the spacer region 5 to the transparent substrate 1. However, the drying process of the present invention is not limited to this, and after the volatile components are evaporated from the spacer particle dispersion in the transparent substrate 1 by vacuum drying or other drying methods, the transparent substrate 1 is heated to thereby form the spacer region 5. The spacer particles may be fixed to the transparent substrate 1.

DESCRIPTION OF SYMBOLS 1 Transparent substrate 2 Spray pipe 3 Pure water discharge nozzle 4 Conveyance roller 5 Spacer area 6 Spacer particle 7 Black matrix 8 Two-fluid nozzle 84 Discharge port 85 Gas inflow pipe 86 Liquid inflow pipe

Claims (6)

A method of manufacturing a liquid crystal display device that forms a gap for enclosing a liquid crystal layer by interposing spacer particles between substrates,
A spacer region forming step of forming a spacer region containing spacer particles by discharging a spacer particle dispersion in which spacer particles are dispersed by an inkjet method on a substrate;
Drying the substrate on which the spacer region is formed, evaporating volatile components from the spacer particle dispersion, and fixing the spacer particles in the spacer region and the substrate;
By washing the substrate to which the spacer particles are fixed with a liquid, a cleaning and removing step of removing the spacer particles existing outside the spacer region;
A method for manufacturing a liquid crystal display device, comprising: In the manufacturing method of the liquid crystal display device of Claim 1,
In the cleaning and removing step, most of the spacer particles in the spacer region are not removed from the substrate, but a liquid having a pressure sufficient to remove spacer particles other than the spacer region is discharged onto the surface of the substrate. A method for manufacturing a liquid crystal display device. In the manufacturing method of the liquid crystal display device of Claim 2,
The liquid is pure water, and in the cleaning and removing step, a method of manufacturing a liquid crystal display device in which high-pressure pure water is ejected toward the substrate while the substrate is conveyed in the horizontal direction. In the manufacturing method of the liquid crystal display device of Claim 2,
The liquid is a liquid in which pure water is mixed with gas, and in the cleaning and removing step, a liquid crystal display device that ejects high-pressure pure water in which gas is mixed toward the substrate while the substrate is transported horizontally. Manufacturing method. In the manufacturing method of the liquid crystal display device in any one of Claims 2 thru | or 4,
The said drying process is a manufacturing method of the liquid crystal display device comprised from the prebaking process which heats a board | substrate at 1st temperature, and the post-baking process which heats a board | substrate at 2nd temperature higher than said 1st temperature. In the manufacturing method of the liquid crystal display device in any one of Claims 2 thru | or 5,
By discharging a larger amount of the spacer dispersion than the amount required in the spacer region forming step, a larger amount of spacer particles than the amount necessary after the drying step is fixed to the substrate, and the necessary amount in the cleaning and removing step is increased. A method of manufacturing a liquid crystal display device, wherein excess spacer particles that have exceeded are removed together with spacer particles that exist outside the spacer region.