JPH0421170B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for treating an insulating alignment film formed on the surface of a glass substrate, which is the inside of a liquid crystal cell of a liquid crystal display element, by a rubbing method. The present invention also relates to a method of manufacturing a liquid crystal display element in which creeping discharge does not occur between transparent conductive film patterns and alignment film characteristics are not impaired.

In liquid crystal display devices such as TN type, as is well known, electrodes of a display pattern are formed by first depositing In ₂ O ₃ , SnO ₂ , etc. on the glass substrate surface facing the inside of the liquid crystal cell. is provided, and further provided thereon is an alignment film that defines the alignment direction of liquid crystal molecules (longitudinal direction). This alignment film is insulative, and generally, once the film is formed, it is rubbed with a wool cloth or synthetic woven cloth in a specific direction that is to be the direction in which the liquid crystal molecules are aligned, so that it has desired alignment characteristics. During this rubbing, a large amount of static electricity is generated in the insulating alignment film. At this time, if the transparent conductive film pattern in contact with this alignment film is divided into multiple parts and each part is not electrically connected to each other and is in a so-called floating state, static electricity will occur during the rubbing process. As the transparent conductive film electrification that accompanies this progresses partially as the rubbing location moves, during the rubbing process, a high potential difference is created between the parts of the pattern made of the transparent conductive film that are floating independently from each other. Creeping discharge occurs and the alignment regulating force of the alignment film is impaired. On the other hand, since voltage must be applied to transparent conductive film patterns for display in order to perform display, after the liquid crystal cell is completed, the pattern terminals used to apply voltage to each pattern from the outside are required. Since these terminals are arranged exposed around the group cells without being covered with an insulating alignment film, by short-circuiting these terminals by pressing a metal plate, etc., the entire display pattern made of a transparent conductive film can be made to have an equal potential. This makes it possible to easily prevent creeping discharge from occurring. However, on the surface of the liquid crystal display element substrate, in addition to the display pattern, patterns necessary mainly only in the manufacturing process, such as alignment patterns for the upper and lower glass substrates and product name display numbers, are formed using a transparent conductive film. Although it is called a transparent conductive film, due to differences in refractive index, etc., the transparent conductive film pattern is easily visible to the naked eye until the liquid crystal is filled in the liquid crystal cell, and is useful for positioning, etc.; is almost invisible under normal conditions. Conventionally, the transparent conductive film pattern described above, which is mainly used only in the manufacturing process, has not always been easy to set terminal lead lines.
It was in an electrostatic floating state because no lead terminal was provided. For this reason, creeping discharge occurs in the vicinity of these transparent conductive film patterns for manufacturing or in the vicinity of the transparent conductive film patterns for display, and the resulting damaged parts of the orientation characteristics become noticeable and result in defective products, causing a decrease in manufacturing yield. There was a problem.

An object of the present invention is to provide a method for manufacturing a liquid crystal display element that does not have the above-mentioned problems.

In order to achieve the above object, in the present invention,
All patterns formed with transparent conductive films on the glass substrate surface, including not only display patterns but also manufacturing process-specific patterns, are applied to the outer periphery of an insulating alignment film that covers the entire display portion of the glass substrate in addition to these patterns. By connecting to any of the terminals arranged in an exposed manner without being covered by this film, and short-circuiting these terminals by crimping a frame that sets a rubbing area made of a metal plate, for example, All parts of the transparent conductive film pattern formed on the glass substrate and under the insulating alignment film were short-circuited and grounded to the same potential. By doing this, pattern short-circuiting is automatically performed using a conductive mask for setting the rubbing area, which is essentially essential for the rubbing process, so there is no decrease in the utilization rate of the glass substrate or an increase in the number of processes. The generation of creeping discharge during the alignment process using the rubbing method was prevented, and the manufacturing yield was improved.

FIG. 1 is a plan view of one embodiment of the present invention, and in the figure, 1
2 is a glass substrate, 2 is a terminal of a display pattern (electrode) made of a transparent conductive film, 2a is a terminal of a pattern made of a transparent conductive film other than for display according to the present invention, 3 is an alignment film, 4
5 is a metal mask, 5 is a pattern exclusively used for the manufacturing process, and 6 is a leader line for leading out a transparent conductive film pattern other than for display according to the present invention to a terminal 2a specially provided on the outer periphery.
In the figure, each pattern is painted black for easy understanding, but in reality, each pattern is of course transparent.
In order to leave the outer periphery of the glass substrate exposed without being covered with the alignment film, it is sufficient to apply the alignment film only to the required portion (that is, to be viewed by the user as a display portion) by a printing method.

As explained above, according to the present invention, generation of creeping discharge in the alignment treatment step by rubbing method can be extremely easily prevented, and manufacturing yield can be improved.

[Brief explanation of drawings]

FIG. 1 is a plan view of one embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Glass substrate, 2... Terminal of display pattern, 2a... Terminal of transparent conductive film pattern other than display use, 3... Alignment film, 4... Metal mask, 5...
...Pattern exclusively for the manufacturing process, 6...Leader line for drawing out a transparent conductive film pattern other than for display to a terminal 2a specially provided on the outer periphery.

Claims (1)

[Claims] 1. In a method for manufacturing a liquid crystal display element having an insulating alignment film that is aligned by a rubbing method, a display electrically connected to a display pattern formed on a glass substrate surface with a transparent conductive film. Both a pattern terminal and a manufacturing process pattern terminal electrically connected to the manufacturing process pattern formed of a transparent conductive film are provided in the periphery of the glass substrate, and the display pattern terminal and the manufacturing process pattern terminal are electrically connected to the manufacturing process pattern terminal formed of a transparent conductive film. A method for manufacturing a liquid crystal display element, characterized in that rubbing is performed in a short-circuited state using a conductive mask that sets a rubbing area.