JPS61103123A - Manufacturing method of liquid crystal display panel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method of manufacturing a liquid crystal display panel used in various display devices, and in particular, to an improvement in the liquid crystal injection process that takes a long time in the manufacturing process of a liquid crystal display panel. It is related to.

A liquid crystal display panel displays characters or images by applying an electric field to a filled liquid crystal, locally changing the orientation state of uniformly oriented liquid crystal molecules, and changing the optical state. It has the feature of being able to be driven at relatively low voltage and low power, and is widely used in flat display panels such as gas discharge display panels and semiconductor light emitting display panels, as well as in various display devices and display parts of various electronic devices. types are proposed.

In the manufacture of liquid crystal display panels, since the distance between the opposing electrodes between the pair of panel substrates constituting the panel structure is extremely small, around 10 μm, degassing of this gap space,
Alternatively, the resistance during liquid crystal injection is high and the workability is the worst in the manufacturing process. In particular, there is a problem in that it takes a considerable amount of time to inject liquid crystal into a predetermined gap space of a panel structure, and it is desired to improve such an injecting process.

[Conventional technology]

Conventional liquid crystal display panels are manufactured using, for example, a display side panel substrate on which a transparent electrode pattern and an alignment film are arranged on the inner surface, and a back side panel substrate on which a transparent electrode pattern or an opaque metal electrode pattern and an alignment film are arranged. A pair of panel substrates are stacked with a spacer interposed therebetween to ensure a predetermined gap, and the periphery thereof is hermetically sealed with a sealing agent or the like to ensure a liquid crystal injection hole.

Thereafter, the predetermined gap space of the panel structure is degassed, and the liquid crystal is injected into the predetermined gap space of the depressurized panel structure using capillary action and pressurization (external pressure), thereby filling the entire gap space. Once the liquid crystal injection hole is filled uniformly, the liquid crystal injection hole is sealed.

[Problem that the invention seeks to solve]

However, in the liquid crystal injection step in the above manufacturing method,
The gap space of the panel structure has an extremely small gap of around 10 μm, and the liquid crystal to be injected has a sufficient viscosity to form a liquid crystal. Therefore, the liquid crystal injection method utilizes reduced pressure in the gap space and capillary phenomenon. However, there is a disadvantage that it requires a considerable amount of time (approximately 2 hours for this type of panel structure), and there is a strong demand for shortening the liquid crystal injection time.

[Means for solving problems]

The above problem is solved by disposing a pair of panel substrates each having an electrode and an alignment film thereon facing each other with a predetermined gap space between them, and placing the liquid crystal in the predetermined gap space of a panel structure whose periphery is hermetically sealed. When injecting the liquid crystal, the liquid crystal is heated in a storage container having a built-in heating means to a high temperature that does not cause deterioration of the properties of the liquid crystal, and the liquid crystal is injected into the gap space in a state in which the liquid crystal has a low viscosity. The problem is solved by a method of manufacturing a liquid crystal display panel according to the invention.

[Effect]

That is, when injecting the liquid crystal into a predetermined gap space of the panel structure, the liquid crystal to be injected is placed in a container containing a heating means and heated to a high temperature that does not cause characteristic deterioration. By injecting the low-viscosity liquid crystal into a predetermined gap space of the panel structure using reduced pressure and capillary action, the injection time can be increased (shortened).

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

The drawing is a perspective view of a main part showing an embodiment of a liquid crystal injection step in a method of manufacturing a liquid crystal display panel according to the present invention.

In the figure, ■ is a panel structure, 2 and 3 are a pair of panel substrates each having a predetermined electrode pattern and an alignment film (not shown) arranged on their inner surfaces, 4 is a predetermined gap space, and 5 is a structure. The peripheral hermetic sealing part, 6 is a liquid crystal injection hole, and 7 is a liquid crystal injection hole.
8 is a liquid crystal storage container, 8 is a liquid crystal storage section, 9 is a liquid crystal, and 10 is a built-in heater section.

Now, as described above, a pair of panel substrates 2.3 each having an electrode pattern (not shown) are placed in a predetermined gap space 4.
In order to inject the liquid crystal into the predetermined gap space 4 of the panel structure 1 which is arranged facing each other and hermetically sealed with an adhesive, first, the panel structure 1 and the liquid crystal 9 to be injected are shown in the diagram. For example, a liquid crystal storage container 7 having a built-in heater section housed in a raised manner is placed on top of the liquid crystal storage container 7 in an airtight chamber, and the panel structure 1 is placed so that its liquid crystal injection holes 6 face each other. placed at a distance from each other.

Next, the inside of the airtight chamber is evacuated by a vacuum pump or the like to a predetermined vacuum, and the predetermined gap space 4 of the panel structure 1 is reduced in pressure! 3 (vacuum state).

On the other hand, the built-in heater section 10 of the liquid crystal storage container 7 heats the liquid crystal 9 to a high temperature (such as within the allowable driving temperature range of the liquid crystal) that does not cause a change in the composition or deterioration of the characteristics of the liquid crystal 9.

At this time, it is preferable that the temperature of the panel structure 1 itself is approximately the same as the above-mentioned heating temperature.

Next, the liquid crystal injection hole 6 of the panel structure 1 is brought into contact with the liquid crystal whose viscosity has been reduced by the heating in the liquid crystal storage container 7, and in this state, the pressure inside the airtight chamber is leaked to atmospheric pressure. As a result, liquid crystal is injected into the predetermined gap space 4 of the panel structure 1 through the liquid crystal injection hole 6 by capillary action and external pressure.

When the entire surface of the gap space 4 is uniformly filled with liquid crystal, the panel structure 1 is taken out and the liquid crystal injection hole 6 is sealed to form an airtight structure.

By doing so, the liquid crystal injection time is halved compared to the conventional method, and the efficiency of the liquid crystal injection process is significantly improved.

In the above embodiments, an electric heater or the like is used as the heating means built into the liquid crystal storage container 7, but the invention is not limited to this example. The temperature of the liquid crystal may be controlled to a predetermined temperature based on the temperature of the water. It goes without saying that heating means such as infrared irradiation can also be applied.

〔Effect of the invention〕

As is clear from the above description, according to the method for manufacturing a liquid crystal display panel according to the present invention, the liquid crystal injection time is significantly shortened, the liquid crystal injection process is made more efficient, and the productivity is improved.

Furthermore, by heating the liquid crystal and panel components in a vacuum before injecting the liquid crystal, the occlusion 'D1 in the liquid crystal after injection can be reduced.
It also has excellent side effects such as reducing impurity gas, preventing display defects, equalizing characteristics, and extending life.

Therefore, it is extremely advantageous to apply it to the manufacture of not only this type of liquid crystal display panel but also electrophoretic display panels and the like.

[Brief explanation of drawings]

The drawing is a perspective view of a main part showing an embodiment of a liquid crystal injection step in a method of manufacturing a liquid crystal display panel according to the present invention. In the figure, ■ is a panel structure, 2 and 3 are a pair of panel substrates, 4 is a predetermined gap space, 5 is an airtight sealing part, 6 is a liquid crystal injection hole, 7 is a liquid crystal storage container, 8 is a liquid crystal storage part, 9 is LCD, 10
indicates the built-in heater section.

Claims (1)

[Claims] When a liquid crystal is injected into a predetermined gap space of a panel structure in which a pair of panel substrates each having an electrode are arranged facing each other with a predetermined gap space and the periphery thereof is hermetically sealed, a heating means is built in to inject the liquid crystal into the predetermined gap space. A method for manufacturing a liquid crystal display panel, characterized in that the liquid crystal is heated to a high temperature that does not cause characteristic deterioration of the liquid crystal in a containing container, and the liquid crystal is injected into the gap space in a state in which the liquid crystal has a low viscosity.