JP2006139120A - Method for manufacturing liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a foreign matter adhered to a rubbing cloth from being transferred to a substrate to be subsequently processed, in a rubbing step for a liquid crystal display device. <P>SOLUTION: A foreign matter removing substrate 5, from which the foreign matter is made to be easily removed by attaching a projecting and recessing portion on the surface, is arranged. Then, after rubbing treatment of a glass substrate with an alignment layer formed on the surface thereof, and before rubbing a subsequent glass substrate 7, a rubbing roll 2, around which the rubbing cloth 1 is wrapped, is pressed to the foreign matter removing substrate 5 and rotated and moved to a fixed direction, similar to an operation in the usual rubbing treatment. The foreign matter attached to the foreign matter removing substrate 5 is removed while the glass substrate to be subsequently processed is rubbed with the refreshed rubbing cloth 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a method for manufacturing a liquid crystal display device, and more particularly to a rubbing process which is one of manufacturing processes for a liquid crystal display device.

In the manufacturing process of a liquid crystal display device, a rubbing process is necessary to align liquid crystal molecules in a predetermined direction. In this rubbing process, a cloth such as rayon is wound around a metal roll, and the entire surface of the glass substrate on which an alignment film is formed is rubbed (rubbed) from the end while rotating the metal roll at a constant speed. Is.

  A rubbing process according to a conventional example will be described with reference to FIG. By rubbing a rubbing cloth 1 made of fiber such as rayon or nylon around a rubbing roller 2 and rubbing a glass substrate 3 placed on the stage 4 and having an alignment film (not shown) formed on the surface in a certain direction, A physical stripe-shaped groove is formed on the surface of the glass substrate 3. By this rubbing step, alignment films formed on the glass substrate 3 are aligned in a predetermined direction, and liquid crystal molecules injected in a subsequent step can be aligned in a predetermined direction.

  However, in this rubbing process, if there is a glass substrate that easily peels off an alignment film, other thin films, etching residues, etc., the alignment film is rubbed by the rubbing cloth 1, and therefore, as shown in FIG. Foreign matter (peeled material) may adhere to the surface, particularly the tip of the cloth pile 10. If the rubbing process is continued in a state where the foreign matter adheres to the rubbing cloth 1, the foreign matter may adhere (transfer) to the glass substrate of the next process or damage the alignment film surface.

In order to avoid such a situation, the rubbing cloth can be replaced with a new one at each rubbing step. In addition, a liquid crystal display device in which a foreign substance removing portion is provided in a region where an alignment film of a glass substrate is not formed has been proposed (for example, see Patent Document 1).
JP2001-318380

In this way, if there is a part where a foreign substance adheres to the surface of the alignment film on the glass substrate or a part with a scratch, the alignment of the liquid crystal molecules is disturbed, resulting in unevenness of the liquid crystal display and the quality of the liquid crystal display device There is a problem of lowering.

  As a method for solving the above problems, the rubbing cloth can be replaced with a new one at the time of the rubbing process as described above, but considering the productivity and cost, dozens to hundreds of rubbing with the same rubbing cloth Processing is usually performed. Moreover, even if the foreign substance removing portion is provided in a region where the alignment film is not formed on the surface upstream of the glass substrate, there are the following problems. First, since it is necessary to form a dedicated pattern for removing foreign substances on the same substrate, manufacturing costs are increased.

  In addition, there is a problem in that a foreign matter removal pattern that is high enough to affect the cell gap cannot be formed. Furthermore, if the foreign matter removal action is performed on the same glass substrate, the foreign matter may be scattered rather than enhancing the foreign matter removal function, and may adhere to a region (display region) where a nearby alignment film is formed. . Furthermore, there is a possibility that foreign matter adhering to the rubbing cloth is transferred to the glass substrate for the next processing.

The manufacturing method of the liquid crystal display of this invention was made in view of the said subject, and has the following characteristics. That is, the method for manufacturing a liquid crystal display according to the present invention includes a step of rubbing a substrate on which an alignment film is formed using a rubbing roller wound with a rubbing cloth, and the rubbing roller before rubbing the next substrate. A step of removing the foreign matter adhering to the rubbing cloth and a step of removing the foreign matter adhering to the foreign matter removal substrate by pressing and rotating the foreign matter on the foreign matter removal substrate. It is.

  According to this manufacturing method, since the rubbing cloth can be kept free of foreign matters by using the foreign matter removing substrate, it is possible to effectively prevent foreign matters from being transferred to the glass substrate for the next treatment. In addition, since the same rubbing cloth can be repeatedly refreshed and used, the rubbing cloth replacement process can be reduced as much as possible, which is excellent in terms of productivity and cost.

  In addition, the foreign matter adhered to the rubbing cloth is transferred to the rubbing cloth substrate by using the foreign substance removing substrate, but when the foreign substance removing substrate is used again to refresh the rubbing cloth, the foreign matter remains on the substrate. Then, there is a problem that foreign matter is transferred to the rubbing cloth again. Then, the said problem can be solved by removing the foreign material adhering to a foreign material removal board | substrate each time. In addition, according to this process, the foreign substance removal substrate can be repeatedly refreshed and used, which is excellent in terms of productivity and cost.

  The method for manufacturing a liquid crystal display device according to the present invention is characterized in that the step of removing the foreign matter adhering to the foreign matter removing substrate uses a dry cleaner.

  Furthermore, the method for manufacturing a liquid crystal display device according to the present invention is characterized in that the step of removing the foreign matter adhering to the foreign matter removing substrate uses a dust removing tape.

  In the method for manufacturing a liquid crystal display device according to the present invention, the foreign substance removing substrate is made of the same material as the substrate.

  In addition, the method for manufacturing a liquid crystal display device according to the present invention is characterized in that irregularities are formed on the surface of the foreign substance removal substrate.

According to the manufacturing method of the present invention, the rubbing cloth and the foreign substance removal substrate can be kept free of foreign substances, and the foreign substance can be effectively prevented from being transferred to the substrate for the next treatment. The quality of the display device can be improved. In addition, since the rubbing cloth replacement process is reduced, the productivity is excellent. Further, the rubbing cloth and the foreign substance removing substrate can be repeatedly refreshed and used, and the cost can be reduced.

Embodiments of the present invention will be described with reference to the drawings. First, as shown in FIG. 1, a glass substrate 3 having an alignment film (not shown) formed on the surface is placed on a stage 4. Here, for example, a polyimide resin is used for the alignment film.

  Next, a rubbing roller 2 around which a rubbing cloth 1 made of fiber such as rayon or nylon is wound is pressed against the glass substrate 3 and rotated in a certain direction from the end thereof, thereby rubbing the entire surface of the glass substrate 3.

  Next, as shown in FIG. 2, the rubbing roller 2 around which the rubbing cloth 1 that has been subjected to the rubbing treatment is wound is refreshed by using the foreign substance removing substrate 5 installed in the previous stage of the stage 4. FIG. 3 is a cross-sectional view showing a process of refreshing the rubbing cloth 1 using the foreign substance removal substrate 5.

  In the present invention, the rubbing roller 2 is pressed against the foreign substance removal substrate 5 and rotated in a certain direction as in the normal rubbing process. Here, the same glass substrate as the glass substrate 3 can be used as the foreign substance removal substrate 5. Although the surface of the foreign substance removal substrate 5 has a certain degree of foreign substance removal effect even if it is flat, in order to make it easier to remove the foreign substance 6 adhering to the rubbing cloth, as shown in FIG. It is preferable to do. This is because the foreign matter 6 can be caught and scraped off at the uneven portion. Moreover, such an uneven | corrugated | grooved part can be formed by the stripe pattern which consists of a metal thin film on the glass substrate surface. The thickness of the foreign substance removal substrate 5 is preferably the same as that of the glass substrate 3 in order to make the pressing force of the rubbing roller 2 uniform.

  According to the foreign matter removing step, as shown in FIG. 3, the foreign matter 6 adhered by the rubbing process is transferred from the rubbing cloth 1 to the foreign matter removing substrate 5, so that the rubbing cloth 1 can be refreshed.

  And while performing this process, the glass substrate 7 of the next process is installed on the stage 4. Next, the glass substrate 7 of the next process is rubbed with the refreshed rubbing cloth 1, and during this time, as shown in FIG. 4, the foreign matter 6 transferred onto the foreign matter removal substrate 5 by the above process is removed. Unlike the glass substrate 3, the foreign substance removing substrate 5 has no alignment film or element on its surface, and therefore it is easy to remove foreign substances and can be easily refreshed.

  For example, a dry cleaner 8 can be used as a method of removing the foreign matter adhering to the foreign matter removing substrate 5 (FIG. 4A). That is, the foreign matter 6 attached to the foreign matter removal substrate 5 can be wiped out by the wind force emitted from the dry cleaner 8. The removal of foreign substances with a dry cleaner does not require the use of special chemicals, and therefore can be reduced in both time and cost.

  Further, as another method, a roller around which the dust removing tape 9 is wound can be used (FIG. 4B). That is, the foreign material adheres (transfers) to the dust removal tape by pressing and rotating the roller wound with the adhesive dust removal tape 9 against the foreign material removal substrate 5. Then, the foreign matter on the foreign matter removal substrate 5 can be removed by peeling the dust removing tape 9 to which the foreign matter is adhered from the foreign matter removal substrate 5.

  Then, before further rubbing the next substrate, the rubbing roller 2 is pressed against the foreign material removal substrate 5 from which the foreign material has been removed by the above processing and is rotated in a certain direction to remove the foreign material 6 attached to the rubbing cloth 1. . Thereafter, the next substrate is rubbed using the rubbing roller 2 from which the foreign matter has been removed. Hereinafter, the above-described steps, that is, cleaning of the foreign substance removal substrate 5, removal of foreign substances from the rubbing roller 2 by the foreign substance removal substrate 5, and rubbing treatment are repeated.

  Through the above series of steps, the rubbing cloth 1 is refreshed by using the clean foreign substance removing substrate 5 without foreign substances every time the rubbing process is performed, so that the foreign substances adhering to the rubbing cloth 1 are applied to the glass substrate 7 for the next processing. It is possible to prevent transfer.

It is a perspective view which shows the manufacturing method of the liquid crystal display device concerning embodiment of this invention. It is a perspective view which shows the manufacturing method of the liquid crystal display device concerning embodiment of this invention. It is sectional drawing which shows the manufacturing method of the liquid crystal display device concerning embodiment of this invention. It is a perspective view which shows the manufacturing method of the liquid crystal display device concerning embodiment of this invention. It is a perspective view which shows the manufacturing method of the conventional liquid crystal display device. It is sectional drawing which shows the manufacturing method of the conventional liquid crystal display device.

Explanation of symbols

1 rubbing cloth 2 rubbing roller 3 glass substrate 4 stage 5 foreign matter removing substrate 6 foreign matter 7 glass substrate for the next treatment 8 dry cleaner 9 dust removing tape 10 pile

Claims (5)

Rubbing a substrate having an alignment film formed on the surface using a rubbing roller wound with a rubbing cloth; and
Before the rubbing treatment of the next substrate, the rubbing roller is pressed against the foreign matter removing substrate and rotationally moved, thereby removing foreign matters attached to the rubbing cloth;
Removing foreign matter adhering to the foreign matter removal substrate;
A method of manufacturing a liquid crystal display device, comprising: The method for manufacturing a liquid crystal display device according to claim 1, wherein a dry cleaner is used in the step of removing the foreign matter adhering to the foreign matter removing substrate. 2. The method of manufacturing a liquid crystal display device according to claim 1, wherein a dust removing tape is used in the step of removing the foreign matter adhering to the foreign matter removing substrate. The method of manufacturing a liquid crystal display device according to claim 1, wherein the foreign substance removing substrate is made of the same material as the substrate. The method for manufacturing a liquid crystal display device according to claim 1, wherein unevenness is formed on a surface of the foreign substance removal substrate.

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