KR100296957B1 - Thin film lcd device sealing method - Google Patents

Abstract

The present invention relates to a thin film type liquid crystal display element sealing method, unlike a conventional sealing method in which a liquid crystal injection space is formed by adhering an upper substrate and a lower substrate having a plurality of spacers therebetween using a sealant (adhesive agent). A welding process using simple heat treatment means without using an agent (or an adhesive) is directly bonded between the plastic substrates of the thin film to form a target liquid crystal injection space. Therefore, the productivity and production yield of the liquid crystal display device of the thin film, as well as the manufacturing cost of the liquid crystal display device can be significantly reduced.

Description

Thin Film Liquid Crystal Display Device Sealing Method {THIN FILM LCD DEVICE SEALING METHOD}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal display device (LCD device), and more particularly to a method for sealing a space to be filled with a liquid crystal between a lower substrate and an upper substrate when manufacturing a liquid crystal display device using a thin transparent plastic material. It is about.

In general, a liquid crystal display device, which is a kind of flat panel display device that can be applied to a wall-mounted television, is a device that displays a desired image on a panel by applying a voltage between transparent electrodes (gate electrode and signal electrode).

The liquid crystal display device manufactures a lower substrate, manufactures an upper substrate, and then forms and seals a predetermined space having a plurality of spacers between the lower substrate and the upper substrate, and fills and seals the liquid crystal in the sealed space. in need.

In other words, the mixture of the sealant and the catalyst is mixed at a constant ratio and slowly stirred to give a catalyst reaction time of about 30 minutes to 60 minutes so as to eliminate air bubbles, thereby completing the sealant (for example, an epoxy resin). By sealing the upper substrate and the lower substrate with a sealant through a dispensing method or a screen printing method well known in the art, a liquid crystal injection space in which a liquid crystal is filled in a subsequent process is formed.

More specifically, the dispensing method is, for example, by applying a sealant using a sealant supply pipe 404 to a predetermined portion (i.e., a sealant forming region line) on the lower substrate 402, as shown in FIG. 4A. A sealant region 406 having an arbitrary sealing pattern is formed, and the screen printing method uses a printed substrate 408 on which the sealing pattern is formed, as shown in FIG. 4B as an example, to form a predetermined portion on the lower substrate 402. Applying a sealant to the portion (ie, sealant forming region line) forms a sealant region 406 having any sealing pattern.

Next, when the application of the sealant having an arbitrary pattern (that is, a pattern having a space to fill the liquid crystal) is completed on the lower substrate through the above-described process, as shown in Figure 4c, the upper substrate 410 ) And the lower substrate 402 are bonded and sealed.

That is, the top substrate, as shown in FIG. 4D, so that the sealant is evenly flattened after about 30-40 minutes of curing at a temperature of about 60-80 ° C. depending on the thickness of the dispense or screened sealant. The adhesion between the upper substrate 410 and the lower substrate 402 is completed by leaving it at room temperature for about an hour while applying a predetermined pressure to the 410 and the lower substrate 402.

Subsequently, by raising the temperature to a polymerization temperature for a predetermined time to remove the solvent in the sealant film formed between the upper substrate 410 and the lower substrate 402, at least about 60 minutes at the polymerization temperature of 120-135 ℃ By waiting, a sealing pattern (namely, liquid crystal injection space) is completed.

FIG. 5 shows a time axis and a temperature axis of a polymerization profile for bonding and sealing a daughter upper substrate to a lower substrate in the conventional method as described above.

In other words, the conventional method requires a very long processing time to seal the liquid crystal display device, which leads to a problem that the productivity is remarkably decreased, and that a defect or the like occurs during a complicated process of several steps. There is a problem that this remarkably falls.

Therefore, in recent years, in order to solve the above-mentioned problems, there have been attempts to employ a UV curable sealant. However, in the case of such a method, the polymerization time can be reduced to several minutes to several tens of minutes. Complex processes such as printing, leveling, UV processes, and the like cannot be avoided, and poor adhesion deterioration due to a decrease in adhesion strength of the bonded part can not be avoided.

On the other hand, in recent years, for various applications of the liquid crystal display device, it has been attempted to use a flexible thin film of a transparent plastic material as the substrate (upper substrate and lower substrate), in the case of such a plastic material liquid crystal display element According to the sealing process, apart from the complexity of the process, due to the characteristics such as bending and use, the poor adhesion between the adhesion between the upper substrate and the lower substrate is very serious situation.

In view of the above, it has been attempted to use a flexible adhesive (or sealant) such as silicone or urethane. However, silicone type adhesives have high gas and gas permeability, and thus bubbles are generated in the liquid crystal. It is difficult to use, and the urethane type adhesive has a problem of adversely affecting the liquid crystal composition in the long term and shortening the life of the liquid crystal display element.

Accordingly, an object of the present invention is to provide a thin film type liquid crystal display device sealing method capable of sealing a liquid crystal space formed between an upper substrate and a lower substrate through a simple heat treatment process without using an adhesive. There is this.

In order to achieve the above object, in the present invention, the method for sealing a thin film type liquid crystal display device includes a thin film type liquid crystal display device having a liquid crystal injection space having a predetermined pattern in which a plurality of spacers are disposed between an upper substrate and a lower substrate made of a flexible transparent plastic material. A sealing method, comprising: aligning an upper substrate with a lower substrate on which a plurality of spacers are formed; And melting a part of the upper substrate and the lower substrate by attaching a heating means to a predetermined pattern portion of the upper substrate, and bonding the heating substrate to a predetermined pattern.

1 is an exemplary view illustrating a process of sealing a device space in which a liquid crystal is filled by using a heating rod in a state in which a lower substrate and an upper substrate overlapping a plurality of spacers are stacked according to an embodiment of the present invention. ego,

2 is an exemplary view illustrating a process of sealing a device space in which a liquid crystal is filled by using a heating rod in a state in which a lower substrate and an upper substrate having a plurality of spacers interposed therebetween are stacked according to another embodiment of the present invention. Is,

3 is a diagram illustrating a process of sealing a device space in which a liquid crystal is filled by using a heating rod in a state in which a lower substrate and an upper substrate having a plurality of spacers interposed therebetween according to another embodiment of the present invention are illustrated. Degrees,

FIG. 4 is an exemplary view illustrating a process of sealing a lower substrate and an upper substrate having a plurality of spacers interposed therebetween by using an adhesive according to a conventional method.

FIG. 5 is a diagram illustrating a polymerization profile for bonding and sealing a daughter upper substrate to a lower substrate in a conventional method, with a time axis and a temperature axis.

<Description of the code | symbol about the principal part of drawing>

102: lower substrate 104: upper substrate

106: heating rod 108: crimp heating line

110: sealing line pattern 112: pattern heating plate

114: multi sealing line pattern

Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment according to the present invention.

First, the core technical aspect of the present invention, without using a sealant (or adhesive), a thin film type (for example, polyester plastics having a thickness of about 100-200 μm, polycarbonate, cell acetate acetate butytate, polyolefin, etc.) The sealing process for forming the target liquid crystal injection space through the sealing process of the plastic material liquid crystal display element, that is, a simple heat treatment means, which is the object of the present invention through this technical means The bar can be easily achieved.

Example 1

1 is an exemplary view illustrating a process of sealing a device space in which a liquid crystal is filled by using a heating rod in a state in which a lower substrate and an upper substrate overlapping a plurality of spacers are stacked according to an embodiment of the present invention. to be.

Referring to FIG. 1, in this embodiment, the liquid crystal injection space formed between the upper substrate and the lower substrate is not sealed by using an adhesive as in the conventional method described above, but a thin plastic substrate, that is, the upper substrate 102. ) And the lower substrate 104 on which a plurality of spacers (not shown) are formed on the upper part are brought into close contact with each other and heated to an arbitrary target temperature, for example, approximately 150-300 ° C while maintaining the close contact. By melting the plastic material of the upper substrate 102 and the lower substrate 104 by directly welding the heating rod 106 to the predetermined sealing line pattern 108 and proceeding in the direction of the arrow, the liquid crystal injection space is Form. Here, the heating temperature range of the heating rod is not limited to, for example, 150-300 ℃, it may vary to a lower or higher temperature depending on the material properties of the film used as the substrate.

At this time, the temperature of the heating rod 106 used in the welding process can be adjusted according to the properties of the plastic material, generally a temperature of about several tens of degrees higher than the melting point of the plastic substrate.

Therefore, since the plastic material of the upper substrate 102 and the lower substrate 104 is directly melted and bonded using the welding process, adhesive properties can be obtained as compared to the conventional method of bonding using an adhesive. And problems such as a decrease in adhesive force caused by the conventional method can be reliably solved.

In addition, although the detailed illustration in FIG. 1A is omitted, the heating rod 106 may be set to be mounted on a device connected to the personal computer, and to proceed according to an input pattern provided from the personal computer. Accordingly, the present invention is very advantageous for application to liquid crystal display devices having various shapes.

Therefore, according to the present embodiment, as in the above-described conventional method of using the sealant, the liquid crystal injection space can be quickly made in a simple process (i.e., only one welding process) without performing a complicated process that requires a lot of time. The sealing process can be realized to improve productivity and production yield of the liquid crystal display device as well as to significantly reduce manufacturing costs.

Example 2

2 is an exemplary view illustrating a process of sealing a device space in which a liquid crystal is filled by using a heating rod in a state in which a lower substrate and an upper substrate having a plurality of spacers interposed therebetween are stacked according to another embodiment of the present invention. to be.

The liquid crystal display element sealing method according to the present embodiment is substantially the same as the above-described embodiment 1 in that the liquid crystal injection space is formed by bonding the upper substrate and the lower substrate through a welding process using a heating rod. However, the fact that the welding process is performed a plurality of times (for example, twice, three times, etc.) to form a plurality of adhesive lines (ie, multi sealing lines 114) between the upper substrate 102 and the lower substrate 104. It differs from Example 1 mentioned above.

Therefore, in this embodiment, in addition to the effect obtained in the above-described embodiment 1 has another advantage that can maintain a more firm adhesive force between the upper substrate and the lower substrate.

Example 3

3 is a diagram illustrating a process of sealing a device space in which a liquid crystal is filled by using a heating rod in a state in which a lower substrate and an upper substrate having a plurality of spacers interposed therebetween according to another embodiment of the present invention are illustrated. It is also.

Referring to FIG. 3, in the present exemplary embodiment, a liquid crystal to be formed without performing a welding process that continuously proceeds along a sealing line pattern on an upper substrate by using a heating rod as in the first and second embodiments described above. The pattern heating plate 112 having the same shape as that of the injection space is prepared in advance, and the upper substrate 102 and the lower substrate 104 having a plurality of spacers (not shown) formed on the upper portion are brought into close contact with each other in a correct position. It is different from the above-described Embodiments 1 and 2 in that a liquid crystal injection space is formed in one welding step of bringing the pattern heating plate 112 heated to a predetermined temperature into close contact with the target position of the upper substrate while maintaining the temperature.

Therefore, according to the present embodiment, not only the same effect as in the above-described embodiments 1 and 2 can be obtained, but also the sealing time can be further shortened as compared with the above-described embodiments 1 and 2, and the other can achieve greater productivity. Has an advantage.

Therefore, the present invention does not use a sealant (or adhesive), unlike a conventional sealing method in which an upper substrate having a plurality of spacers is bonded to a lower substrate using a sealant (adhesive agent) to form a liquid crystal injection space. By directly bonding between the plastic substrates of the thin film through a welding process using a simple heat treatment means to form a target liquid crystal injection space, the productivity and production yield of the liquid crystal display device of the thin film as well as the manufacturing cost of the liquid crystal display device It can save a lot.

Claims (3)

A method of sealing a thin film type liquid crystal display element having a liquid crystal injection space of a predetermined pattern for placing a plurality of spacers between an upper substrate and a lower substrate made of a flexible transparent plastic material, Aligning the upper substrate with a lower substrate on which a plurality of spacers are formed; And And heating a portion of the upper substrate to a predetermined pattern portion of the upper substrate to melt a portion of the upper substrate and the lower substrate to bond the predetermined portion to the predetermined pattern. The thin film type liquid crystal display element sealing method according to claim 1, wherein a heating temperature range of the heating means is 150 to 300 ° C. The thin film type liquid crystal display element sealing method according to claim 1 or 2, wherein the heating means is a pattern heating plate having a shape corresponding to a heating rod or a sealing line pattern.