KR101999336B1 - Liquid crystal display, method of manufacturing the same - Google Patents

Abstract

The present invention discloses a liquid crystal display device and a manufacturing method thereof. A method of manufacturing a liquid crystal display device according to the present invention includes the steps of: placing a liquid crystal panel on a stage; forming a preliminary cut groove by irradiating a laser beam onto a notch formation area of the liquid crystal panel after deflecting the placed liquid crystal panel; And forming a notch by using an auxiliary cutting means on a liquid crystal panel having a preliminary cutting groove formed therein, wherein the step of forming the preliminary cutting groove includes a step of cutting the laser beam So as to form a preliminary cut groove.
Since the non-contact type machining method using laser is applied, the present invention can eliminate the periodical equipment replacement and the post-machining cleaning process, which were inevitable in the machining method of the mechanical contact method using the conventional groove wheel, .

Description

TECHNICAL FIELD [0001] The present invention relates to a liquid crystal display (LCD)

More particularly, the present invention relates to a liquid crystal display device having a notch formed on one side of a liquid crystal panel, and a method of manufacturing a liquid crystal display device using a laser processing method that does not require a polishing process and a cleaning process.

BACKGROUND ART [0002] Liquid crystal displays (hereinafter, referred to as 'LCD') are becoming more and more widespread due to features such as light weight, thinness, and low power consumption driving. According to this tendency, LCD is used for office automation equipment, audio / video equipment and the like.

Such an LCD displays a desired image on a screen by controlling a transmission amount of a light beam according to an image signal applied to a plurality of control switches arranged in a matrix form.

The liquid crystal panel of such a liquid crystal display device is generally formed by laminating a thin film transistor mother substrate, which is a large transparent glass substrate, and a color filter mother substrate, and cutting them into a plurality of liquid crystal cell units.

The thin film transistor mother substrate and the color filter mother substrate are each composed of a plurality of thin film transistor substrates and a plurality of color filter substrates partitioned in units of liquid crystal cells. Therefore, a gate line, a data line, a thin film transistor, a pixel electrode, an alignment film, and the like necessary for forming a plurality of thin film transistor substrates are formed on the mother substrate of the thin film transistor. The color filter mother substrate is provided with a color filter layer, An electrode, and a black matrix are formed.

As described above, in order to cut the mother substrate by the liquid crystal cell, a scribe process is performed by using a diamond wheel to form a cut groove on the mother substrate. Then, an impact is applied to the mother substrate to cut it in units of liquid crystal cells.

After the cutting process, the unit liquid crystal cell is completed through a liquid crystal injection process and an end seal process for sealing the liquid crystal injection port. When the liquid crystal cell is completed, a liquid crystal module process for attaching a printed circuit board including a driving circuit and a control unit is performed to complete a liquid crystal display

However, in recent years, full-touch display devices using a touch screen instead of a keypad have been widely used, and a display device capable of accessing the Internet and browsing the web has been widely used. Such full-touch type display devices have a display on the front side and a home button on the bottom side of the front side.

When the completed unit liquid crystal cell is used in such a display device, a semicircular notch is formed so that a groove button can be coupled to one edge of the unit liquid crystal cell. Such a notch has been produced by mechanical polishing after cutting a bonded mother substrate to form a liquid crystal cell.

1 is a perspective view illustrating a method of processing a liquid crystal panel using a polishing method according to a related art.

1, a liquid crystal panel 10 includes a color filter substrate 10b formed with red (R), green (G), and blue (B) color filters and a black matrix, And a TFT substrate 10a in which a matrix-shaped pixel region is defined by intersecting data lines, and each pixel region is formed with a thin film transistor (TFT) as a switching element.

The TFT substrate 10a is generally formed larger than the color filter substrate 10b because a gate pad and a data pad for supplying a gate driving signal and a data signal are formed on the TFT substrate 10a.

 As shown in the figure, a notch 10c is formed in the non-display area 10a '' at one side edge of the TFT substrate 10a so as to correspond to the groove button of the liquid crystal display device.

In the prior art, the groove wheel 11 rotating at high speed is physically brought into contact with the liquid crystal panel 10 to form the notch 10c.

That is, the TFT substrate 10a is worn using the groove wheel 11 rotating at high speed to form the notch 10c.

At this time, since heat is generated in the region where the groove wheel 11 and the liquid crystal panel 10 are in contact, heat is generated using cooling water, or the groove wheel 11 and the liquid crystal panel 10 are separated from each other for a predetermined time Repeat the process.

Thus, in the conventional polishing method for forming the notch 10c in the liquid crystal panel 10, there is a high possibility that the liquid crystal panel 10 and the groove wheel 11 are damaged. Particularly, since the performance of the groove wheel 11 is important, the groove wheel 11 must be replaced periodically.

In addition, since the glass particles flow into the region inside the liquid crystal panel 10 during the polishing process or the cleaning process must be performed after the process, the process becomes complicated. Further, since the polishing method is a mechanical contact method, There is a problem that the production yield of the liquid crystal display device is lowered because the polishing time is long.

In addition, there is a problem that stress is concentrated on both ends 12 of the notch 10c, which increases the risk of breakage.

One aspect of the present invention is to provide a liquid crystal display device having a notch having a structure for dispersing stress on one side of a liquid crystal panel.

A further object of the present invention is to provide a method of manufacturing a liquid crystal display device using a laser processing method capable of reducing manufacturing cost due to equipment wear in a non-contact manner.

Another object of the present invention is to provide a method of manufacturing a liquid crystal display device using a laser processing method that can effectively reduce thermal diffusion, ensure reliability, and simplify a process.

According to an aspect of the present invention, there is provided a method of manufacturing a liquid crystal display using a laser. The method includes the steps of: placing a liquid crystal panel on a stage; forming a preliminary cutting groove by irradiating a laser beam onto a notch formation region of the liquid crystal panel after deflecting the mounted liquid crystal panel;

And forming a notch by using an auxiliary cutting means on the liquid crystal panel having the preliminary cutting grooves, wherein the step of forming the preliminary cutting grooves includes forming a preliminary cutting groove on the liquid crystal panel so that the reciprocating path of the laser beam, And a beam is irradiated to form a preliminary cut groove.

According to another aspect of the present invention, there is provided a liquid crystal display device. The liquid crystal display device includes a thin film transistor substrate divided into a display region and a non-display region; And a color filter substrate bonded to the thin film transistor substrate and having a color filter array formed in a region corresponding to the display region, and a notch is formed in the non-display region.

In the present invention, the shape of the notch formed in the liquid crystal panel is a spline curve shape, thereby reducing the risk of breakage at both ends of the notch.

Since the non-contact type machining method using laser is applied, the present invention can eliminate the periodical equipment replacement and the post-machining cleaning process, which were inevitable in the machining method of the mechanical contact method using the conventional groove wheel, .

In addition, thermal damage or structural change of the workpiece due to heat diffusion can be prevented, and the polishing process after the cutting and the cleaning process can be omitted, thereby simplifying the liquid crystal panel processing process.

1 is a perspective view for explaining a liquid crystal panel and a method of processing the same using a polishing method according to a related art.
FIGS. 2A and 2B are perspective views illustrating a method of manufacturing a liquid crystal panel using a laser according to an embodiment of the present invention.
3 is a cross-sectional view taken along line I-I 'of Fig. 2 (a).
4 is a cross-sectional view taken along line II-II 'of FIG. 2 (b).

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings showing a liquid crystal panel using a laser and a processing method thereof. The following embodiments are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Therefore, the present invention is not limited to the embodiments described below, but may be embodied in other forms. In the drawings, the size and thickness of an apparatus may be exaggerated for convenience. Like reference numerals designate like elements throughout the specification.

Laser processing is a method of finely processing a workpiece by locally heating the workpiece by converting energy having a specific light called laser into thermal energy. The laser machining is capable of locally heating the workpiece to melt or emit light by means of a laser.

Precision machining such as a bearing hole of a watch or precision boring and cutting of a nonmetallic material such as diamond ceramics is used for machining because it does not contact the workpiece.

FIGS. 2A and 2B are perspective views illustrating a method of manufacturing a liquid crystal panel using a laser according to an embodiment of the present invention.

2A and 2B, a method of processing a liquid crystal panel using a laser according to the present invention includes the steps of placing a liquid crystal panel 100 on a stage (not shown) of a laser processing apparatus, Forming a preliminary cut groove 120 (see FIG. 3) by irradiating a laser along the line L1 to be cut on the liquid crystal panel 100, forming a preliminary cut groove 120 (see FIG. 3) , See FIG. 3) is cut by applying force to the auxiliary cutting means 130. A represents a cut region.

The liquid crystal panel 100 is composed of an upper color filter substrate 100b and a lower TFT substrate 100a.

The TFT substrate 100a includes a display region 100a 'in which a switching element and a pixel electrode are formed, and a non-display region 100b' in which a driving integrated circuit for applying a signal to the switching element is implemented in a region outside the display region 100a ' (100a "). The TFT substrate 100a is larger than the color filter substrate 100b due to the non-display area 100a ''.

In the display region of the TFT substrate 100a, a plurality of gate lines and data lines intersect with each other to form a plurality of pixel regions, and a TFT element Are formed. A pixel electrode is formed in the pixel region to form an electric field by a data signal supplied in accordance with a turn-on / off operation of the TFT.

A black matrix is formed on the color filter substrate 100b so as to correspond to the gate lines, the data lines, and the thin film transistor elements of the TFT substrate 100a, and a region corresponding to the pixel region of the TFT substrate 100a is colored red R, green (G), and blue (B) color filter layers are formed. When the liquid crystal display device is in a TN (Twist Nematic) mode or VA (Vertical Alignment) mode, a common electrode may be formed on the color filter layer of the color filter substrate 100b.

However, in the IPS (In-Plane Switch) mode or the FFS (Fringe Field Switch) mode, the pixel electrode and the common electrode are formed in the pixel region of the TFT substrate 100a.

When the liquid crystal panel 100 of the present invention turns on any one of the thin film transistors formed on the TFT substrate 100a, the transmittance of the liquid crystal is changed by the electric field formed between the pixel electrode and the common electrode. The light emitted from the light source passes through any one of the RGB color filter layers of the liquid crystal and color filter substrate 100b to display an image while one of red (R), green (G), and blue (B) .

As shown in the drawing, a notch 100c is formed in the non-display area 100a '' at one side edge of the TFT substrate 100a so as to correspond to the groove button of the liquid crystal display device.

To form the notch 100c, the liquid crystal panel 100 is first loaded on the stage of the laser cutting apparatus. Liquid crystal panels of various sizes may be mounted on the stage and moved or stopped in a predetermined direction by a driving unit provided on the lower side of the stage.

The liquid crystal panel 100 mounted on the stage is subjected to a alignment step. The alignment step is a step of aligning the liquid crystal panel 100 by checking and correcting the position of an accurate cut line.

When the correct cutting line position is secured through the above-described alignment step, laser is irradiated while reciprocating along the line along which the material is to be cut (L1) as shown in Fig. 2 (a). Whereby the preliminary cutting groove 120 (see FIG. 3) is formed. At this time, the laser irradiation unit may be transported in the X, Y direction by the X, Y axis drive unit, or may be transported in the Z direction by the Z axis drive unit.

Therefore, it can be freely moved in X, Y, Z directions at a desired speed along a desired cutting path.

When the preliminary cutting groove 120 (see FIG. 3) is formed, mechanical cutting is applied to the cutting area A of the liquid crystal panel 100 by the auxiliary cutting means 130 as shown in FIG. 2 (b). Thus, the cut region A is removed and a notch 100c is formed at one side edge of the TFT substrate 100a of the liquid crystal panel 100. [

The central portion of the notch 100c has an arbitrary second radius of curvature R2. Further, both side edges of the notch 100c have arbitrary first and third curvature radii R1 and R3, respectively. That is, the first and third curvature radii R1 and R3 may be formed in a region connected to one edge of the notch 100c and the TFT substrate 100a.

The second curvature radius R2 of the center portion is preferably larger than the first and third curvature radiuses R1 and R3. It is also preferable that the first and third curvature radiuses are equal to each other. The relationship between the first radius of curvature and the second radius of curvature is preferably 10R1 <R2 <20R1.

By forming the both ends of the notch 100c in a curved shape as described above, it is possible to prevent the concentration of stress and reduce the risk of breakage.

Since the process of forming the notch 100c at one side edge of the liquid crystal panel 100 corresponds to the end of the process of manufacturing the liquid crystal panel 100 in the process of forming the notch 100c, If some of them are cracked or damaged, a great deal of damage will occur.

Therefore, the present invention utilizes a laser, but limits the type of laser and the method of laser irradiation to achieve process reliability.

3 is a cross-sectional view taken along the line I-I 'in FIG. 2 (a) to illustrate the process of forming the preliminary cut groove 120. Referring to FIG. 3, the method of fabricating a liquid crystal panel using a laser according to the present invention is characterized in that the preliminary cutting groove 120 is formed by using an ultra-short pulse laser having low thermal diffusion.

When a general laser is used, when a laser beam is irradiated along a line L1 to be cut on the TFT substrate 100a in order to form the preliminary cut groove 120, the oscillation of electrons occurs, Heat is transferred from the surface of the substrate 100a to the inside. Due to such thermal diffusion, the surface of the preliminary cutting groove 120 and a part of its inner portion cause thermal damage or structural change.

Such thermal damage or structural change causes microcracks on the TFT substrate 100a. This is because the TFT substrate 100a is made of glass and has high brittleness. Therefore, a general laser is not suitable for processing the TFT substrate 100a made of glass.

When a general laser is used, a large amount of residue is generated when the laser beam is irradiated. These residues are often attached to the surface of the TFT substrate 100a after being heated at the time of processing, and are often difficult to remove.

Also, when a general laser is used, the cross-sectional shape of the preliminary cut groove 120 is not the ideal V line but the vertex 121 becomes a blunt V line.

This low sharpness may cause the cut surface 140 (see FIG. 4) to become non-smooth in the step of applying force to the TFT substrate 100a on which the preliminary cut grooves 120 are formed.

However, in the case of using the ultra-short pulse laser, when a laser beam is irradiated along the line to be cut L1 on the TFT substrate 100a for forming the preliminary cut groove 120, only the portion irradiated with the laser beam is irradiated in an extremely short time . This is because the pulse width of the laser beam is shorter than the time when the heat generated by the mutual reaction between the laser beam and the material propagates to the surroundings, so that heat diffusion hardly occurs. Therefore, the surface of the preliminary cutting groove 120 is smooth because there is little damage due to heat diffusion.

In addition, in the case of using an ultrashort pulse laser, the sectional shape of the preliminary cut groove 120 becomes close to an ideal V.

Because of this high sharpness, the cut surface 140 (see Fig. 4) cut by applying a force to the TFT substrate 100a on which the preliminary cut groove 120 is formed is smoothed.

Therefore, the ultrashort pulse laser is made of glass like the TFT substrate 100a of the present invention, and is advantageous for processing of a material having high brittleness.

In addition to the effect of preventing thermal diffusion, the ultra-short pulse laser can suppress most of the melts and residues formed in the periphery of the TFT substrate 100a and can be easily removed even if it is generated in a very fine powder form.

Ultrashort pulse lasers include femtosecond lasers and picosecond lasers, and picosecond lasers are preferred. The picosecond laser has high output characteristics and a simple internal optical system compared with the femtosecond laser, and it can relatively easily irradiate ultraviolet rays by generating harmonics using the nonlinear medium (SHG, THG, and FHG).

At this time, it is preferable that the light used is light in the ultraviolet region and has a wavelength of 300 nm to 400 nm.

Referring to FIG. 3, the method of working a liquid crystal panel using a laser according to the present invention is characterized by forming a preliminary cutting groove 120 by irradiating laser in a heat dispersing manner.

In the laser irradiation method of the heat dispersion method, the laser beam is irradiated while reciprocating along the line L1 to be cut on the TFT substrate 100a so that the reciprocating movement path is not overlapped.

As shown in the figure, the laser beam is sequentially irradiated along the Mn (n = arbitrary integer) path in M1 on the TFT substrate 100a. At this time, the movement paths of the laser beams of M1 to Mn do not overlap with each other, and the laser beams of adjacent movement paths overlap each other by only about 50 to 75%.

The laser is irradiated along the M1 to Mn path, and then backward. At this time, the reciprocating paths of the laser beams are not overlapped with each other. Also, the laser beams of the adjacent movement paths are overlapped by about 50 to 75%.

In contrast, when the laser beam is repeatedly irradiated onto the TFT substrate 100a along the same path, heat is concentrated in the path. As a result, the surface of the preliminary cutting groove 120 formed on the TFT substrate 100a is not smooth due to heat damage.

If the surface of the TFT substrate 100a made of glass is not smooth, the rigidity is lowered. Therefore, in order to increase rigidity, a separate polishing process is required after cutting. A cleaning process is also required.

However, the present invention irradiates the laser with the heat dispersion method as described above to prevent intensive heat transfer to only one of the TFT substrate 100a. As a result, the surface of the preliminary cutting groove 120 becomes smooth.

4 is a cross-sectional view taken along line II-II 'of FIG. 2 (b). Referring to FIG. 4, in the method of processing a liquid crystal panel using a laser according to the present invention, a cutting region A is removed by applying a force to a cutting region A by an auxiliary cutting means 130 after a preliminary cutting groove 120 is formed do.

The surface of the preliminary cutting groove 120 is smooth and free from thermal damage. Therefore, the force is uniformly transmitted through the pre-cut groove 120. As a result, the cut surface 140 finally formed after cutting is smoothed.

Therefore, the polishing process after the cutting and the subsequent cleaning process are not necessary, so that the process can be simplified.

The laser processing apparatus used in the present invention is a laser processing apparatus for totally controlling the input / output of an ultra-violet laser beam generated from a laser generating module and other auxiliary devices such as focus, movement and speed of a focus adjusting module, And a control module.

The condensing module may further include a light condensing module disposed between the laser generating module and the substrate and configured to focus the microwave laser beam generated from the laser generating module to a desired focal position.

At least one reflector or interferometer for moving the microwave laser beam generated from the laser generation module along a desired cutting path without a driving module for moving the focusing module, May be used.

10, 100: liquid crystal panel 10a, 100a: TFT substrate
10a ', 100a': Display area 10a '', 100a '': Non-display area
10b, 100b: color filter substrate 10c, 100c:
11: groove wheel 130: auxiliary cutting means
L1: expected line to be cut R1, R2, R3: radius of curvature
A: Cutting areas M1, M2, Mn-1, Mn: Cutting path
120: preliminary cutting groove 140:

Claims (13)

Providing a liquid crystal panel including a thin film transistor substrate divided into a display region and a non-display region, and a color filter substrate bonded to the thin film transistor substrate so as to overlap the display region;
Placing the liquid crystal panel on a stage;
After the alignment of the liquid crystal panel is completed, a laser beam is irradiated along a predetermined line to be cut (L1) on one exposed edge region of the thin film transistor substrate corresponding to a non-display area of the liquid crystal panel to form a preliminary cut groove ; And
And forming a notch having a spline curve shape by removing a part of one side of the thin film transistor substrate by using an auxiliary cutting means on the thin film transistor substrate on which the preliminary cut groove is formed,
The step of forming the preliminary cut-
The laser beam irradiated on the thin film transistor substrate is reciprocated along the line along which the object is intended to be cut L1 and the reciprocating path of the laser beam reciprocating along the line along which the object is to be cut L1 does not overlap with each other, The laser beams being partially overlapped with each other,
Sectional shape of the pre-cut groove is formed in a V-shape with a sharp bottom,
Wherein the notch has a second radius of curvature (R2) at the center, both side edges of the notch have first and third radiuses of curvature (R1, R3), the first and third radiuses of curvature are equal,
And the second radius of curvature (R2) is 10R1 < R2 < 20R1.
The method according to claim 1,
Wherein the laser beam is an ultra-short pulse laser beam.
3. The method of claim 2,
Wherein the ultra-short pulse laser beam is a picosecond (ps) laser beam.
The method according to claim 1,
Wherein the overlapping range of the laser beam irradiated to the adjacent movement paths in the step of forming the preliminary cut groove is 50 to 75%.
delete delete delete The method of manufacturing a liquid crystal display using a laser according to any one of claims 1 to 3, wherein the laser beam has a wavelength ranging from 300 nm to 400 nm.
delete delete delete delete delete

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