KR20060039203A - Liquid dropping apparatus and method for manufacturing liquid crystal display panel by using the apparatus - Google Patents

Abstract

The present invention relates to a liquid crystal dropping apparatus for producing a liquid crystal display panel and a method for manufacturing a liquid crystal display panel using the same, comprising: a syringe body portion on which a liquid crystal is loaded; A needle portion for discharging the liquid crystal onto a substrate to be dropped; A liquid crystal dropping device including a heating unit for heating the liquid crystal so that the liquid crystal discharged from the needle portion has a predetermined temperature, and a method of manufacturing a liquid crystal display panel using the same. As a result, the liquid crystal stably spreads and is uniformly aligned in the process of dropping the liquid crystal into the cell gap between the substrates constituting the liquid crystal display panel, thereby preventing the occurrence of irregularities in the liquid crystal display panel.

Description

Liquid crystal dropping apparatus and manufacturing method of liquid crystal display panel using same {LIQUID DROPPING APPARATUS AND METHOD FOR MANUFACTURING LIQUID CRYSTAL DISPLAY PANEL BY USING THE APPARATUS}

1 is a cross-sectional view of a liquid crystal dropping apparatus according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of main parts of a liquid crystal display panel manufactured using the liquid crystal dropping apparatus of FIG. 1; FIG.

3 is a cross-sectional view showing a state in which a liquid crystal is dropped using the liquid crystal dropping apparatus of FIG. 1.

* Explanation of symbols for the main parts of the drawings

10 liquid crystal dropping device 11: syringe body portion

12: needle part 13: heating part

100 thin film transistor 110 first substrate

121: gate electrode 130: gate insulating film

140: semiconductor layer 161: source electrode

162: drain electrode 170: protective film

180 pixel electrode 210 second substrate

220: black matrix 230: color filter                 

240: overcoat layer 280: common electrode

300: liquid crystal layer 301: liquid crystal

400: sealant 600: alignment layer

The present invention relates to a liquid crystal dropping apparatus and a manufacturing method of a liquid crystal display panel using the same, and more particularly, a liquid crystal dropping apparatus which improves the spread of liquid crystal so that the liquid crystal can be stably aligned in the liquid crystal dropping process of the liquid crystal display panel. And a method of manufacturing a liquid crystal display panel using the same.

In general, a liquid crystal display panel (LCD) forms an image by adjusting light transmittance of liquid crystal cells arranged in a matrix according to image signal information.

The liquid crystal display panel includes a thin film transistor substrate, a color filter substrate attached to face the thin film transistor substrate, and a liquid crystal interposed in a cell gap between the thin film transistor substrate and the color filter substrate.

As a method of interposing a liquid crystal between both substrates of the liquid crystal display panel, there are a liquid crystal injection method using a vacuum pressure and a liquid crystal dropping method.

In the liquid crystal injection method using vacuum pressure, more liquid crystals are supplied to the cell gap than desired liquid crystals or liquid crystals are buried on the outside of the liquid crystal display panel, thereby additionally needing to clean the liquid crystals, and expensive liquid crystals are wasted. In addition, as the size of the substrate is gradually increased, a large amount of time is consumed when the liquid crystal is interposed in the cell gap by a liquid crystal injection method using vacuum pressure.

Therefore, in order to overcome this problem, a liquid crystal dropping method has emerged.

In the liquid crystal dropping method, first, a liquid crystal is dropped on one of a thin film transistor substrate and a color filter substrate, and then the seal lines formed between the thin film transistor substrate and the color filter substrate are cured to firmly bond both substrates.

Here, a method of dropping a liquid crystal onto a substrate is to drop the nematic liquid crystal loaded on the liquid crystal dropping device in a point state on a few points on the substrate, and then to assure the liquid crystal to fill the entire surface of the liquid crystal display panel. In a way. As the liquid crystal falls from the liquid crystal dropping device to the substrate, the liquid crystal first spreads due to the drop impact, and thereafter, secondary spreading is generated by the wetting action with the alignment film.

However, since the liquid crystal in the nematic state has viscous anisotropy and high viscosity, a problem arises in that the liquid crystal spreads anisotropically and friction with the surface of the alignment film is not uniformly aligned. In addition, such a portion may be expressed as spots in the liquid crystal display panel.

Accordingly, it is an object of the present invention to provide an improved liquid crystal dropping apparatus so that the liquid crystal can be stably spread and uniformly aligned.

Moreover, another object of this invention is to provide the manufacturing method of the liquid crystal display panel manufactured using said liquid crystal dropping apparatus.

According to the present invention, there is provided a liquid crystal dropping device for producing a liquid crystal display panel, comprising: a syringe body portion on which a liquid crystal is loaded; A needle portion for discharging the liquid crystal onto a substrate to be dropped; And a heating unit for heating the liquid crystal such that the liquid crystal discharged from the needle portion has a predetermined temperature.

The heating unit preferably heats the liquid crystal through the needle unit.

In addition, it is preferable that the temperature of the liquid crystal discharged from the needle portion is between 40 and 200 degrees.

Thus, the liquid crystal is stably spread and uniformly aligned in the process of dropping the liquid crystal into the cell gap between the substrates constituting the liquid crystal display panel.

Another object of the present invention is to provide a method of manufacturing a liquid crystal display panel, comprising: providing a first substrate and a second substrate; Dropping a liquid crystal having a predetermined temperature onto any one of the first substrate and the second substrate using a liquid crystal dropping device; And arranging the first substrate and the second substrate to face each other, and bonding the first substrate and the second substrate to each other with a sealant.

Here, it is preferable that the temperature of the liquid crystal dropped to the board | substrate by the said liquid crystal dropping apparatus is between 40 degree | times and 200 degree | times.                     

By the manufacturing method of the liquid crystal display panel, the liquid crystal is uniformly oriented to prevent the appearance of a defect in the shape of the liquid crystal display panel.

Hereinafter, a liquid crystal dropping apparatus and a liquid crystal display panel manufactured using the same according to an embodiment of the present invention will be described with reference to the accompanying drawings. In the accompanying drawings, the liquid crystal dropping device and the liquid crystal display panel are schematically shown with the features highlighted, and the liquid crystal display panel uses a liquid crystal display panel using an amorphous silicon (a-Si) thin film transistor (TFT) formed by a five-sheet mask process. It is set as an Example.

As shown in FIG. 1 and FIG. 2, the liquid crystal dropping apparatus 10 according to an embodiment of the present invention includes a syringe body portion 11 in which a liquid crystal 301 in a nematic state is loaded. The heating part for heating the liquid crystal 301 so that the needle part 12 for discharging the liquid crystal 301 to the dropping substrate 110 and the liquid crystal 301 discharged from the needle part 12 have a predetermined temperature. (13).

The liquid crystal 301 is loaded in the syringe body part 11 in a nematic state, but is heated to a predetermined temperature by the heating part 13 to be in an isotropic state, and thus the substrate 110 is formed through the needle part 12. Discharged into the phase. Since the liquid crystal 301 in the isotropic state has a low viscosity having no viscous anisotropy, the liquid crystal 301 falls into the substrate 110 and spreads due to the drop impact, and again wets with the alignment layer 600. By the diffusion, the friction with the alignment film 600 is generated evenly and less, and is stably and uniformly oriented. Here, it is preferable that the temperature of the liquid crystal heated by the heating part 13 and discharged from the needle part 12 is between about 40 degrees and 200 degrees.                     

As a result, defects in the form of spots are prevented from appearing on the liquid crystal display panel.

The heating part 13 heats the liquid crystal 301 through the needle part 12 to raise the temperature of the liquid crystal 301 discharged from the needle part 12 from 40 to 200 degrees, thereby making the liquid crystal 301 isotropic ( Change to an isotropic state. On the other hand, unlike the above-described embodiment, the heating unit 13 may heat the syringe body portion 11 to heat the entire liquid crystal 301 loaded in the syringe body portion 11, in this case liquid crystal evaporation, etc. May cause problems. Therefore, it is most preferable that the heating section 13 heats the liquid crystal 301 immediately before the discharge through the needle section 12 to the predetermined temperature.

Next, a method of manufacturing a liquid crystal display panel using the liquid crystal dropping device 10 described above will be described.

First, the liquid crystal display panel manufactured by the method of manufacturing the liquid crystal display panel according to the present invention will be described. As shown in FIG. 3, the plurality of thin film transistors 100 and the thin film transistor 100 which are switching elements are electrically connected. A first substrate 110 having a plurality of pixel electrodes 180 connected to each other, a second substrate 210 having a black matrix 220, a color filter 230, a common electrode 280, and the like, and a first substrate The liquid crystal layer 300 is filled between the 110 and the second substrate 210.

Referring to the first substrate 110 in detail, the first substrate 110 made of an insulating material such as glass, quartz, ceramic, or plastic may include a plurality of gate lines (not shown) and a plurality of data formed in a matrix form. A thin film transistor (TFT) 100 which is a switching element formed at an intersection point of a line (not shown), a gate line and a data line, and a pixel electrode 180 connected to the thin film transistor 100 are included. A signal voltage is applied to the liquid crystal layer 300 between the pixel electrode 180 and the common electrode 280 of the second substrate 210 to be described later through the thin film transistor 100, and the liquid crystal layer 300 receives this signal. It is aligned with the voltage to determine the light transmittance.

As illustrated in FIG. 3, the thin film transistor 100 includes a gate electrode 121, a gate insulating layer 130, a semiconductor layer 140, an ohmic contact layer 151 and 152, a source electrode 161, and a drain electrode. 162. The gate electrode 121 is formed to branch from a gate line (not shown).

In addition, although not shown, the first substrate 110 further includes a driving circuit part connected to the ends of the gate line and the data line to supply a driving signal, and the thin film transistor 10 may also be formed in the driving circuit part. Many may be formed and used as circuit elements.

The gate insulating layer 130 is made of an insulating material such as silicon nitride (SiNx) or silicon oxide (SiOx), and is stacked on the entire surface of the first substrate 110 on which the gate line (not shown) and the gate electrode 121 are formed. On the gate insulating layer 130 where the gate electrode 121 is located, the semiconductor layer 140 made of amorphous silicon and the ohmic contact layers 151 and 152 made of n + hydrogenated amorphous silicon heavily doped with n-type impurities are sequentially formed. do. Here, the ohmic contacts 151 and 152 are separated at both sides with respect to the gate electrode 121. In addition, unlike the above-described embodiment, the semiconductor layer 140 may be formed of polysilicon.                     

The data line (not shown) and the source electrode 161 and the drain electrode 162 branched from the data line are formed on the gate insulating layer 130 and the ohmic contact layers 151 and 152.

Here, each wiring including a gate line (not shown), a gate electrode 121, a data line (not shown), a source electrode 161, a drain electrode 162, and the like is formed of a single layer of a metal or an alloy. However, in order to compensate for the shortcomings of each metal or alloy and to obtain desired physical properties, they are often formed in multiple layers. For example, aluminum or an aluminum alloy is used as the lower layer, and chromium or molybdenum is used as the upper layer. The lower layer uses aluminum or aluminum alloy with low specific resistance to prevent signal resistance due to wiring resistance, and the upper layer uses chemicals to compensate for the shortcomings of aluminum or aluminum alloy where corrosion resistance is weak and easily broken due to chemicals. The upper layer is formed of chromium or molybdenum, which is highly resistant to chemicals. In recent years, molybdenum, aluminum, titanium, tungsten, and the like are spotlighted as wiring materials, and most of them are used in multiple layers.

A passivation layer 170 made of a photosensitive material is stacked on the first substrate 110 on which the thin film transistor 100 is formed. In other words, the protective film 170 may be formed of silicon nitride (SiNx), plasma enhanced chemical vapor deposition (PECVD), or an a-Si: C: O film or an a-Si: C: F film (low dielectric constant CVD film) and an acrylic resin. An organic insulating film or the like. In the passivation layer 170, a contact hole 171 for exposing a portion of the drain electrode 162 of the thin film transistor 100 or a part of the source electrode 161 may be formed.

The pixel electrode 180 is formed on the passivation layer 170 and the contact hole 171. The pixel electrode 180 is connected to the drain electrode 162 through the contact hole 171, so that the thin film transistor 10 and the pixel electrode 180 are electrically connected to each other. The pixel electrode 180 is formed of a reflective conductive film having a high reflectance such as aluminum (Al) or silver (Ag) in the case of a reflective liquid crystal display panel, and indium tin oxide (ITO) or ITO in the case of a transmissive liquid crystal display panel. It is formed of a transparent conductive film such as indium zinc oxide (IZO). In the case of the reflective-transmissive liquid crystal display panel, the pixel electrode 180 is formed in a structure in which the transparent conductive film and the reflective conductive film are stacked.

Next, the second substrate 210 will be described in detail. The second substrate 210 made of an insulating material such as glass, quartz, ceramic, or plastic, such as the first substrate 110, is striped to have an opening. Alternatively, the black mattress 220 having a lattice shape, a color filter 230 having three primary colors of red, green, and blue or cyan, magenta, and yellow formed in the opening of the black matrix 220, and the color filter 230, respectively. And an overcoat layer 240 formed on the black matrix 220 which is not covered by the color filter 230, and a common electrode 280 formed on the overcoat layer 240.

The black matrix 220 distinguishes between colors of the color filter 230 having red, green, and blue (RGB) or cyan, magenta, and yellow colors to prevent light leakage between adjacent pixels, and light is applied to the thin film transistor 10. It prevents the incident and prevents the poor quality. The black matrix 220 may be made of a single or a combination of multiple metal layers such as chromium, chromium oxide, and chromium nitride, or may be made of a photosensitive organic material to which black pigment is added to block light. Here, carbon black or titanium oxide may be used as the black pigment.

The color filter 230 is formed by repetition of red, green, and blue in the openings of the black matrix 220, respectively, and serves to give color to light passing through the liquid crystal layer 300. The color filter 230 is a colored photosensitive organic material and is made using a known pigment dispersion method.

The overcoat layer 240 serves to protect the color filter 230, the acrylic epoxy material is used as a material.

The common electrode 280 is made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). The common electrode 280 directly applies a signal voltage to the liquid crystal layer 300 together with the pixel electrode 180 of the first substrate 110.

The alignment layer 600 for the alignment of the liquid crystal is formed on the surfaces of the first substrate 110 and the second substrate 210 completed as described above, and both of the substrates 110 and 210 are bonded to each other using the sealant 400. The liquid crystal layer 300 is formed in the space between the two substrates 110 and 210. The sealant 400 seals a cell gap between both substrates 110 and 210 and has a function of maintaining a gap between both substrates 110 and 210. The liquid crystal display panel includes a short 500 for connecting an external voltage to the common electrode 280, and a spacer (not shown) disposed in the display area to maintain a gap between the substrates 110 and 210. More).

In the method of manufacturing the liquid crystal display panel according to the exemplary embodiment of the present invention, the first substrate 110 and the second substrate 210 are each manufactured by a known method, and according to the present invention, A method of dropping liquid crystal between the second substrates 210 will now be described in detail.

After loading the liquid crystal 301 in a nematic state on the liquid crystal dropping device 10, the loaded liquid crystal 301 is dropped to a point state at a few points on the first substrate 110. At this time, the liquid crystal 301 is heated through the needle portion 12 from the heating portion 13 immediately before being discharged from the needle portion 12 to have a temperature of 40 to 200 degrees, the state of the liquid crystal 301 It will change to an isotropic state. When the liquid crystal 301 changed to the isotropic state falls on the first substrate 110, it is primarily spread by the drop impact, and then secondarily diffused by the wetting action with the alignment layer 600. As described above, since the liquid crystal 301 has an isotropic state in the process of diffusing, the friction with the alignment layer 600 is evenly generated. Therefore, the liquid crystal 301 can be stably diffused and can be evenly aligned.

After the sealant 400 is coated on the second substrate 210 along the seal line, the sealant 400 is disposed to face the first substrate 110 to be firmly bonded to each other by curing the sealant 400. The coating method of the sealant 400 may include a screen printing method and a dispenser method, and the screen printing method may damage the substrate, and when the substrate becomes large, consumption of the sealant 400 may be reduced. As it is uneconomical in many cases, the dispenser method is mainly used. The dispenser method is a method of applying the sealant 400 to a desired shape by moving the syringe while discharging the sealant 400 in a small amount from the needle by applying the pressure to the syringe shaped syringe. Curing of the sealant 400 may use a method of ultraviolet curing or thermal curing depending on the material of the sealant 400.                     

Here, unlike the above-described embodiment, the liquid crystal 301 may be dropped on the second substrate 210 and the sealant 400 may be applied to the first substrate 110, as well as the liquid crystal 301 on the same substrate. May be added dropwise and the sealant 400 may be applied. However, when the liquid crystal 301 is dropped on the same substrate and the sealant 400 is applied, the sealant 400 may react with the liquid crystal.

In addition, the process of dripping the liquid crystal 301 and curing the sealant 400 is usually performed in a vacuum chamber.

The present invention is not limited to the above-described embodiment, and any liquid crystal 301 may be applied to any kind of liquid crystal display panel as long as the liquid crystal 301 is interposed between the substrates 110 and 210 constituting the liquid crystal display panel. .

By such a configuration, the operation and effects of the liquid crystal dropping apparatus 10 and the manufacturing method of the liquid crystal display panel using the same according to an embodiment of the present invention will be described. Since the liquid crystal 301 is stably spread and uniformly aligned in the process of dropping the liquid crystal 301 into the cell gap, it is possible to prevent defects in the form of stains from appearing on the liquid crystal display panel.

As described above, according to the present invention, it is possible to provide an improved liquid crystal dropping apparatus for stably spreading and uniformly aligning liquid crystals and a method of manufacturing a liquid crystal display panel which prevents defects from appearing using the same. Will be.

Claims (5)

In the liquid crystal dropping device for liquid crystal display panel manufacture, A syringe body portion in which liquid crystal is loaded; A needle portion for discharging the liquid crystal onto a substrate to be dropped; And a heating unit for heating the liquid crystal so that the liquid crystal discharged from the needle portion has a predetermined temperature. The method of claim 1, And the heating part heats the liquid crystal through the needle part. The method of claim 1, And a temperature of the liquid crystal discharged from the needle portion is between 40 and 200 degrees. In the manufacturing method of a liquid crystal display panel, Providing a first substrate and a second substrate; Dropping a liquid crystal having a predetermined temperature onto any one of the first substrate and the second substrate using a liquid crystal dropping device; And arranging the first substrate and the second substrate to face each other and bonding the first substrate and the second substrate to each other. The method of claim 4, wherein And a temperature of the liquid crystal dropped onto the substrate by the liquid crystal dropping device is between 40 and 200 degrees.

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