JPS6048737B2 - Manufacturing method of liquid crystal display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a liquid crystal display device, and in particular to a method for manufacturing a liquid crystal display device having a spacer inserted between substrates to reliably maintain the gap between opposing electrodes at a predetermined dimension and easy to assemble. The present invention relates to a method of manufacturing the device.

Liquid crystal display devices utilize a phenomenon in which when an electric field is applied to an organic compound called liquid crystal, which has properties intermediate between a liquid and a solid, the optical properties of that part change.
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This is to display the following information.

FIG. 1 is an exploded perspective view of the main parts of an example of a conventionally commonly used liquid crystal display device, in which two substrates 1a and lb
are placed facing each other.

In order to provide a gap of a predetermined size between the substrates, spacers 2 are placed and laminated along the periphery of both substrates 1a and lb, and after liquid crystal is injected inside, the periphery is hermetically sealed. (not shown). Note that a letter-shaped transparent electrode is provided on the inner surface of the substrate 1a so as to obtain a desired pattern, and an electrode facing this transparent electrode is provided on the inner surface of the other substrate 1 (both (not shown). In this case, the above-mentioned optical change of the liquid crystal largely depends on the distance between the electrodes, that is, the thickness of the spacer 2.
For example, if the thickness of the spacer 2 is not uniform, the spacing between the electrodes will vary, making it impossible to obtain a uniform display pattern. Furthermore, if the thickness of the spacer 2 differs, the time response characteristics of optical changes will also differ. ) Therefore, in order to obtain a liquid crystal display device with uniform and stable display characteristics,
A spacer having a uniform and constant thickness is required.

However, as spacers in conventional liquid crystal display devices, the following types are often used.

1 Mix abrasive grains and fine particles into the adhesive, and apply this to the substrate 1a (
or 1b) that constitutes the spacer 2 by coating on the surface by a method such as printing.

2. The spacer 2 is constructed by printing and applying an adhesive onto the substrate 1a (or 1b) in advance, and then laying glass fiber or Mylar foil on top of this.

3 A spacer is created by punching a thermoplastic adhesive such as vinyl acetate, epoxy nylon, or nylon containing abrasive grains, fine particles, or glass fibers into a predetermined shape and placing it on the substrate 1a (or 1b). 2
What constitutes.

However, although Particle No. 1 can easily constitute a spacer, there is a problem of overlapping due to variation in particle size and irregular shape, and it is extremely difficult to maintain dimensional accuracy as a spacer.

In addition, 2 is a spacer that improves the accuracy of the thickness dimension of the spacer, which is the problem with the former, but it is a spacer with a fine linear shape such as glass fiber, or a spacer with a thickness of several μm to several + μm such as Mylar foil. It is extremely difficult to efficiently arrange and attach a film-like spacer to an adhesive on a substrate, which poses problems in assembly work.

3. Since the thermoplastic adhesive is used, the heat resistance of the sealing part is poor, and it is difficult to efficiently arrange a thin thermoplastic adhesive film of several μm to several + μm on the substrate. The problem is that it is bad.

Therefore, an object of the present invention is to provide a liquid crystal display having spacers that have high dimensional accuracy and are easy to assemble. An object of the present invention is to provide a method for manufacturing a display device.

In order to achieve this object, a method of manufacturing a liquid crystal display device according to the present invention uses a spacer formed by mixing finely cut glass fibers into an adhesive.

Hereinafter, a liquid crystal display device according to the present invention will be explained in detail using the drawings.

FIG. 2 is an enlarged view of essential parts of an embodiment of a liquid crystal display device manufactured according to the present invention, and the same parts as in FIG. 1 are designated by the same reference numerals.

In the figure, 13 is an adhesive applied along the peripheral portion of the substrate 1a, and 4 is a glass fiber mixed into the adhesive 3. The diameter of the glass fiber 4 is selected to be equal to the required spacing between the substrates, and the diameter of the glass fiber 4 is selected in advance to be larger than the diameter of the glass fiber 4, for example, 1.1 to 0. Cut to .5- length.

The needle-shaped glass fibers 4 and the adhesive 3 are thoroughly stirred in an appropriate ratio, and then spread around the substrate 1a using a screen having slits through which the needle-shaped glass fibers 4 can pass with plenty of room. Print and apply along.

Next, as shown in FIG. 3, the other substrate 1b is superimposed on the adhesive 3 on the substrate 1a, and held with a predetermined pressure until the adhesive 3 hardens. A spacer 2 is formed whose diameter is determined by the diameter of the glass fiber 4.

; The mixing ratio of the acicular glass fiber and the adhesive and the pressure applied to the upper and lower substrates are important items that are determined based on parameters such as the mechanical strength of the glass fiber and the repulsive force due to the viscosity and elasticity of the adhesive.

In other words, if the amount of glass fiber is too small, there will be less contact with the substrates 1a and 1b as a spacer against the J pressing force, and the substrate will become non-uniform and easily deformed, and the pressure applied to the glass fiber will increase. Due to mechanical damage, the voids tend to become uneven. On the other hand, as the amount of glass fibers increases, the probability that the glass fibers will overlap increases.However, by applying appropriate pressure to both substrates 1a and 1b, they will slip and shift or break, so that they overlap and the spacer 2 (See Figure 2).

Furthermore, if the number of glass fibers is further increased, the spacer 2 will be constructed with the glass fibers overlapping each other, resulting in non-uniform gaps.

Therefore, as mentioned above, the mixing ratio of glass fiber and adhesive varies depending on the material of the adhesive, and when low melting point glass is used as the adhesive, the mixing ratio is 0.01~? % of glass fiber is mixed and a pressure of 0.05 to 10k9/d is applied, or when a thermosetting adhesive such as epoxy or acrylic is used as an adhesive, 0.01 to 10wt. %
Mixed with glass fiber, 0.01~10k9/CT
When a pressure of 1 is applied, substantially uniform voids having the same diameter as the spacer can be created with good yield.

By adopting this configuration, the wire diameter accuracy of the glass fiber mentioned above is ±0.5 μm, which is superior to the variation in particle size and irregularity of shape of other abrasive grains and fine particles. Spacers with high precision and uniform thickness can be easily obtained.

This ensures that the spacing between the substrates is more uniform and ensures the most basic characteristic of this type of display device, which is that a uniform display pattern can be obtained. Furthermore, since the spacer can be constructed by mixing finely cut glass fibers into an adhesive and printing and applying the mixture, assembly efficiency is extremely high.

Note that although the glass fibers 4 may be printed in an overlapping manner, they may slip and shift or break due to the pressure applied when the substrates 1a and 1b are overlaid, so that the glass fibers 4 overlap to form the spacer 2. This is not the case (see Figure 2).

As explained above, according to the present invention, the spacer is constructed using an adhesive mixed with a glass fiber having excellent wire diameter accuracy cut into a size slightly longer than the wire diameter. Since the spacing between the opposing electrodes is uniform and constant, a liquid crystal display device with stable display characteristics can be obtained. In addition, various excellent effects such as extremely high assembly efficiency are achieved.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing the general structure of a general liquid crystal display device, and FIGS. 2 and 3 are enlarged plan views of essential parts showing a spacer portion of a liquid crystal display device according to the present invention, and enlarged essential parts. A longitudinal section is shown. 1a, 1b...Substrate, 2...Spacer, 3...Adhesive, 4...Glass fiber.

Claims (1)

[Claims] 1. A first substrate having a transparent electrode, a second substrate having a counter electrode facing the transparent electrode, and a spacer inserted between these substrates to maintain the distance between the two electrodes at a predetermined dimension. In the method for manufacturing a liquid crystal display device including a liquid crystal sealed between both electrodes, glass fibers cut into longitudinal pieces are mixed into an adhesive of 0.01 to 10 wt %, and then the glass fiber-containing adhesive is mixed with the adhesive. A step of forming a liquid crystal cell by applying a predetermined pressure to one or both of the first substrate and the second substrate by screen printing in a predetermined shape, and then combining the two substrates; A method of manufacturing a liquid crystal display device, wherein the distance between the first substrate and the second substrate is determined by the diameter of the glass fiber.