JPH02280124A - Production of liquid crystal display element - Google Patents

Abstract

PURPOSE:To obtain the liquid crystal display element which is regulated in the spacing between upper and lower substrates to a desired value by uniformly spraying spherical spacers formed by coating the circumferences of central nuclei consisting of a ferromagnetic material with a synthetic resin on substrate surfaces. CONSTITUTION:A spray nozzle 3 which ejects the air contg. the spacers 1 toward the glass substrate 5 is provided above the substrate 5 and a cover 4 bored with a slit 7 for dispersion is installed between the nozzle 3 and the substrate 5. Further, DC electromagnet coils 6 for attracting the spacers are disposed alongside both ends of spray patterns. Since the spacers 1 having the central nuclei made of the ferromagnetic material are dragged laterally, i.e. toward both end sides of the substrate by the electromagnet coils 6, the spacers 1 are distributed at nearly a uniform density over the entire part in the transverse direction of the substrate 5. The spacers 1 which are not too hard and are not too weak are nearly uniformly dispersed and disposed on the substrate in such a manner and, therefore, the uniform formation of the spacing size between the upper and lower substrates to the desired value is possible.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides magnetism to a spacer for regulating the substrate gap of a liquid crystal cell to a predetermined length, and uses this magnetism to attach the spacer to the substrate surface. The present invention relates to a method for manufacturing a liquid crystal display element, in which non-magnetic foreign matter and dust are widely dispersed and distributed on the substrate surface, and non-magnetic foreign matter and dust mixed with spacers are removed.

[Prior art] The gap between the upper and lower glass substrates filled with liquid crystal in a liquid crystal display element is extremely narrow, and if the dimensions cannot be maintained uniformly, the response speed and threshold voltage may vary depending on the location on the display surface. Since a difference occurs, resulting in display unevenness, spacers having predetermined dimensions are interspersed between the upper and lower substrates to regulate this dimension. However, even if a spacer is used, if the material is too hard, it may dig into the alignment film or transparent conductive film electrode formed on the substrate surface, interfering with their operation.
If it is too weak, it may deform or break, resulting in problems such as a narrowing of the distance between the substrates.

As a countermeasure to this latter problem, for example, the use of polystyrene spherical spacers was disclosed in Japanese Patent Application Laid-Open No. 57-210.
It is disclosed in Publication No. 323.

[Problems to be Solved by the Invention] However, with the above-mentioned conventional countermeasure techniques, the spacers are not necessarily uniformly distributed on the substrate, and if they are not uniformly distributed, even one gap size is not uniformly formed. There are problems such as color unevenness occurs, and foreign matter caught up during spacer dispersion cannot be removed, resulting in unevenness in the gaps.

The present invention provides a method for manufacturing a liquid crystal display element, in which spacers that are neither too hard nor too weak are distributed almost uniformly on a substrate, and foreign matter, dust, etc. that are mixed in during the spacer dispersion can be selectively and easily removed. The purpose is to provide.

[Means for Solving the Problems] In order to achieve the above object, the present invention uses a spherical spacer whose periphery is coated with a synthetic resin around a central core made of a ferromagnetic material, and utilizes the effect of a magnetic field on this spacer. The spacers are uniformly distributed over the substrate surface, or non-magnetic foreign matter and dust are selectively removed from the substrate surface where the spacers are distributed. More specifically, a spacer is used in which the diameter of the ferromagnetic core is 30 to 60% of the total diameter after being coated with synthetic resin, the spacer is mixed with gas, and the spacer is applied to the substrate surface together with the gas from a nozzle. A magnetic attraction force is applied to the ejected spacers to spread the spacers laterally and uniformly disperse them on the substrate, or to place the substrate on a static magnetic field generating means. Then, spacers are scattered on the substrate surface on the opposite side from the means, and while the spacers are strongly adsorbed to the substrate surface, a clean and dust-free gas flow is blown onto the substrate surface on which the spacers are scattered, What is necessary is to selectively remove foreign matter and dust on the substrate surface.

[Function] Although the central core made of ferromagnetic material does not deform plastically, the surrounding synthetic resin is so-called plastic, so there is no risk of damaging the transparent conductive film or alignment film formed on the surface of the substrate, and the central core does not deform plastically. Even if the magnetic material is opaque, there is no problem because the surrounding synthetic resin is transparent. Since the central core of the ferromagnetic material of the spacer is affected by the magnetic field, the spacer is also stretched toward the side magnetic poles and is widely and uniformly distributed over the substrate surface. It is obvious that if the spacer is strongly attracted to the substrate surface by the action of the electromagnet, the spacer will not be blown away even if a strong gas flow is blown away, and only the non-magnetic foreign matter will be blown away.

[Example 1] FIG. 1 shows a spacer according to the present invention, in which the diameter A of the ferromagnetic volume 2 is 30 to 60% of the diameter X of the entire spacer 1.
shall be. This is because if it is made too small, the attraction effect of the magnetic field will be insufficient, and if it is made too large, the surrounding plastic film will become thin and its effect will disappear.

FIG. 2(a) shows a first embodiment of the present invention, in which a spray nozzle 3 for jetting air mixed with spacers toward the substrate 5 is installed on a glass substrate 5, and the nozzle 3 and the substrate 5 are
A top view showing a state in which a cover 4 with a dispersion slit 7 is arranged at a distance of 10 m+ from the substrate in the middle of the spray pattern, and DC electromagnetic coils 6 for spacer attraction are arranged on the sides of both ends of the spray pattern. , FIG. 2(b) is a side view of the above state, and FIG. 2(c) is a side view of the above state, and FIG. 2(c) is a projection of the above state onto a plane perpendicular to the direction in which the nozzle 3 and the substrate 5 move relative to each other (indicated by arrows in the figure). FIG. As can be clearly seen from Fig. 2(c), if only the air flow from the nozzle 3 is used, the spacer distribution density will be high directly under the nozzle 3, and the spacer distribution density will be low near both ends of the substrate. Since the electromagnetic coil 6 is disposed in the spacer 1 and the spacer 1 having a central core made of ferromagnetic material is spread out to the sides, that is, to both ends of the substrate,
The spacers 1 can be distributed at a substantially uniform density throughout the width direction of the substrate 5. Note that the nozzle 3, cover 4, and slit 7 are fixed, and the substrate 5 moves relative to them at an appropriate speed in the direction of the arrow, so that the spacer is uniformly spread over the entire width of the substrate surface in this direction. It is distributed.

FIG. 3 shows a second embodiment of the present invention, in which spacer 1
The substrate 5 on which the powder has been sprinkled is placed on a static magnetic field generating means 9 (for example, an electromagnet excited by direct current), and a clean air stream from which dust and the like has been thoroughly removed is blown from a nozzle 8 onto the substrate 5. In this way, non-magnetic foreign matter is selectively blown away.

[Effects of the Invention] As explained above, according to the present invention, ferromagnetic spacers that are neither too hard nor too weak are distributed on the substrate at a uniform density,
In addition, since foreign matter between the spacers can be effectively removed, it is possible to manufacture a liquid crystal display element in which the gap between the upper and lower substrates is regulated to a desired value.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a spacer according to the present invention, and FIG. 2 (a
), (b), and (c) are explanatory diagrams of the first embodiment of the present invention,
FIG. 3 is an explanatory diagram of a second embodiment of the present invention.

Claims (1)

[Claims] 1. As a spacer that is interposed between two glass substrates facing each other across a narrow gap in the liquid crystal cell to regulate the gap to a predetermined length, the periphery of the central core made of ferromagnetic material is coated with synthetic resin. Using spherical spacers, the spacers can be uniformly distributed over the substrate surface by utilizing the effect of the magnetic field on the spacers, or non-magnetic foreign matter and dust can be selectively removed from the substrate surface on which the spacers have been scattered. 1. A method for manufacturing a liquid crystal display element, characterized in that: