JPH04291238A - Manufacture of matrix type liquid crystal panel - Google Patents

Abstract

PURPOSE:To prevent an orientation film from being damaged by static electricity at an orienting process and to improve yield by connecting the abutting terminal parts of upper and lower segment electrodes by a short pattern much thinner than the width of the electrodes and trimming the pattern after an orientation processing. CONSTITUTION:By connecting an upper segment electrode 1 and a lower segment electrode 2, possibility for the orientation film to be damaged by discharging is extremely reduced since no potential difference is generated between upper and lower segments even when static electricity is generated in the case of orientation. Further, since a short pattern 5 is much thinner than the width of the electrodes, it is not turned to a level confirmed by naked eyes even when the orientation film is affected by the trimming of a laser after the orienting process. This method can be applied not only to a simple matrix panel but also to an active panel integrating a TFT or terminal elements.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a simple matrix liquid crystal panel used in laptop computers, word processors, and the like.

0002

BACKGROUND OF THE INVENTION Liquid crystal panels, which first appeared as displays for clocks, calculators, etc., have come to be used in a wide range of fields as their image quality has improved and their size has increased. Liquid crystal panels used in laptop computers and word processors are broadly classified into two types: matrix type and active matrix type. Among these, simple matrix type liquid crystal panels have a simpler structure, require fewer processes, and are advantageous in terms of cost, compared to active matrix type liquid crystal panels in which a switching element is fabricated in each pixel using a semiconductor process. It is especially widely used in consumer equipment.

Next, an outline of a method for manufacturing a matrix type liquid crystal panel will be described below. (1) An ITO layer is formed by sputtering or vapor deposition on a glass substrate, which will be a lower substrate, and patterned into stripes to form upper segment electrodes 1 and lower segment electrodes 2, which will become column electrodes. (2) ITO is formed into a film on the upper substrate in the same manner, and patterned in stripes in a direction perpendicular to the lower substrate to form the common electrode 3. (3) A polyimide liquid, which is a liquid crystal aligning agent, is applied to the surfaces of both glass substrates on which electrodes are formed, and the substrate is placed in a furnace and fired. (4) Perform alignment treatment by rubbing the surface of the glass substrate coated with the alignment agent with a roll covered with cotton velvet. (5) Both glass substrates are bonded together with the orientation treated surfaces facing inside and the segment electrodes and common electrodes being perpendicular to each other. (6) Cut and separate the glass and process it into individual panels. (7) Enclose liquid crystal inside the panel.

[0004] When manufacturing liquid crystal panels, attention must be paid to static electricity generated during the process. When a glass substrate is charged with static electricity, it attracts dust floating around it, causing visual defects such as distorting the panel gap, and sometimes damaging the electrodes and alignment film due to discharge. To eliminate such defects caused by static electricity, humidify the environment or
It is best to suppress the generation of static electricity itself by eliminating static electricity using an ionizer or by minimizing friction with the glass substrate.

[0005]

The problem here is the orientation step (4). Since this process involves directly rubbing the glass substrate with a velvet roll, static electricity is inevitably generated. In particular, in many matrix liquid crystal panels, one active area is divided into upper and lower halves in order to improve display characteristics such as crosstalk and contrast, and the segment electrodes are also separated at the upper and lower halves. Therefore, if a discharge occurs between the upper and lower segment electrodes where a potential difference occurs due to static electricity during alignment, not only the ends of the electrodes but also the alignment film in the vicinity will be damaged. When a driving voltage is applied to such a liquid crystal panel, the orientation of the liquid crystal in the damaged area becomes distorted, giving the appearance that part of the pixel is missing.

[0006]

[Means for Solving the Problems] In order to solve the above problems, the present invention, when patterning segment electrodes on a glass substrate, electrically connects the abutting ends of the upper and lower segment electrodes with a short pattern that is much thinner than the electrode width. After the orientation process, the pattern was trimmed and cut using a laser.

[0007]

[Operation] In the above manufacturing method, since the upper and lower segments are electrically connected during orientation, even if static electricity is generated, no potential difference occurs and no discharge occurs. Therefore, damage to the electrode end portions and the alignment film caused by electrostatic discharge can be prevented.

[0008]

[Example] An example of the manufacturing method of the present invention will be described below. (1) An ITO layer is formed by sputtering or vapor deposition on a glass substrate, which will be a lower substrate, and patterned into stripes to form upper segment electrodes 1 and lower segment electrodes 2, which will become column electrodes. At this time, a short pattern 5, which is much thinner than the electrode width, is formed on the abutting ends 4 of the upper and lower segment electrodes to electrically connect them. (2) ITO is formed into a film on the upper substrate in the same way, and patterned in stripes in a direction perpendicular to the lower substrate to form common electrodes 3 that will become row electrodes. (3) A polyimide liquid, which is a liquid crystal aligning agent, is applied to the surfaces of both glass substrates on which electrodes are formed, and the substrate is placed in a furnace and fired. (4) Perform alignment treatment by rubbing the surface of the glass substrate coated with the alignment agent with a roll covered with cotton velvet. (5) Both glass substrates are bonded together with the orientation treated surfaces facing inside and the segment electrodes and common electrodes being perpendicular to each other. (6) Cut and separate the glass and process it into individual panels. (7) Enclose liquid crystal inside the panel. (8) Trim the short pattern 5 with a laser to electrically separate the upper segment electrode 1 and the lower segment electrode 2.

FIG. 1 shows an enlarged view before laser trimming in the manufacturing method of the present invention, and FIG. 2 shows an enlarged view after laser trimming in the manufacturing method of the invention. In FIGS. 1 and 2, 1 is an upper segment electrode, 2 is a lower segment electrode, 3 is a common electrode, 4 is a butt end, and 5 is a short pattern. If the upper segment electrode and lower segment electrode are connected as shown in Figure 1, even if static electricity is generated during alignment, there will be no potential difference between the upper and lower segments, so there is a very low possibility that the alignment film will be damaged by discharge. becomes less. Furthermore, since the short pattern is much thinner than the width of the electrode, even if trimming with a laser after the alignment process affects the alignment film, it will not be visible to the naked eye.

When a simple matrix type liquid crystal panel was manufactured using the manufacturing method of the present invention, no damage to the alignment film due to electrostatic discharge occurred during the alignment process, and the manufacturing yield was dramatically improved compared to before implementation. Although the present invention has been mainly described with reference to a method for manufacturing a simple matrix panel, it can also be applied to a method for manufacturing an active panel in which one of the glass substrates incorporates a TFT or a two-terminal element.

[0011]

[Effects of the Invention] As detailed above, according to the present invention, damage to the alignment film due to static electricity during the alignment process of a simple matrix liquid crystal panel can be prevented by extremely simple means, and the manufacturing yield can be greatly improved. Can be done.

[Brief explanation of the drawing]

FIG. 1 is an enlarged view before laser trimming in the manufacturing method of the present invention.

FIG. 2 is an enlarged view after laser trimming in the manufacturing method of the present invention.

FIG. 3 is an enlarged view of a conventional manufacturing method.

[Explanation of symbols]

1 Upper segment electrode 2 Lower segment electrode 3 Common electrode 4 Butt end 5 Short pattern

Claims (1)

[Claims] Claim 1: In a method for manufacturing a matrix type liquid crystal panel in which liquid crystal is sealed between two glass substrates, a short circuit is formed in advance, which is much narrower than the width of the electrodes, at the butt portions of segment electrodes that are divided into upper and lower segments. Manufacture of a matrix type liquid crystal panel characterized in that the upper and lower segment electrodes are divided by forming a pattern, electrically connecting the upper and lower segment electrodes, and trimming the short pattern with a laser after alignment treatment. Method.