JP2008020541A - Liquid crystal display device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal display device and its manufacturing method. <P>SOLUTION: The liquid crystal display device is composed of: a first substrate and a second substrate opposed to each other; a liquid crystal layer located between the first substrate and the second substrate; and a seal pattern which surrounds the liquid crystal layer and is formed of frit glass or glass paste. The frit glass comprises lead oxide PbO, zinc oxide ZnO, silicon oxide SiO<SB>2</SB>and barium oxide BaO powders, filler and binder material. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device and a manufacturing method thereof.

Recently, as the society enters the full-fledged information age, the display field that visually expresses various electrical signal information is rapidly developing.
Recently, TFT-LCD, a thin-film transistor TFT-type liquid crystal display device with excellent performance such as thinning, lightening, and low power consumption has been developed, replacing the existing cathode ray tube (CRT) (Cathode Ray Tube). Yes.

  The image display principle of the liquid crystal display device utilizes the optical anisotropy and polarization properties of the liquid crystal. Liquid crystals have a thin and long molecular structure, optical anisotropy having directionality in the alignment, and polarization properties that change the alignment direction of molecules depending on the size when placed in an electric field.

  Accordingly, the liquid crystal display device includes, as a constituent element, a liquid crystal panel formed by bonding an array substrate having a pixel electrode and a common electrode and a color filter substrate on surfaces facing each other with a liquid crystal layer in between. The alignment direction of the liquid crystal molecules is arbitrarily adjusted according to the change in the electric field between the electrodes, and various images are displayed using the changed light transmission rate.

  Recently, in particular, the active matrix system, in which pixels, which are the basic units of image representation, are arranged in a matrix system and switching elements are arranged in each pixel and independently controlled, has excellent resolution and moving image display capability. However, TFT-LCD (hereinafter referred to as a liquid crystal display device) uses a thin film transistor TFT with such a switching element.

  The structure of the liquid crystal display device will be described with reference to FIG. 1 and FIG.

  FIG. 1 is a cross-sectional view schematically showing a conventional liquid crystal display device, and FIG. 2 is a cross-sectional view taken along line II-II in FIG.

  As shown in the figure, the conventional liquid crystal display device 1 has a configuration in which the array substrate 11 and the color filter substrate 61 are bonded to each other with the liquid crystal layer 90 therebetween. Among these, the lower array substrate 11 includes a plurality of gate wirings 13 and data wirings 30 which intersect with each other in the vertical and horizontal directions and define a large number of pixel regions P. A thin film transistor Tr is provided at the intersection of the gate line 13 and the data line 30 and is connected to the pixel electrode 50 provided in each pixel region P. The thin film transistor Tr includes a gate electrode 15, a semiconductor layer 23 having an active layer 23a and an ohmic contact layer 23b, a source electrode 33, and a drain electrode 35. The gate insulating film 20 is located on the gate electrode 15, and the insulating layer 40 has a drain contact hole 43 exposing the drain electrode 35.

  In addition, a black matrix 63 is formed on the back surface of the upper color filter substrate 61 facing this. The black matrix 63 is connected to a grid-shaped first black matrix 63a surrounding each pixel region P so as to block the gate wiring 13, the data wiring 30, and the thin film transistor Tr, and one end of the first black matrix 63a. A second black matrix 63b is formed. Inside this lattice, red R, green G, and blue B color filter patterns 66a, 66b, and 66c are formed which are repeatedly arranged in order so as to correspond to each pixel region P. A common electrode 70 formed of a transparent conductive material is provided below the red R, green G, and blue B color filter patterns 66a, 66b, and 66c.

  Further, a liquid crystal 90 is interposed between the pixel electrode 50 of the array substrate 11 having the structure described above and the common electrode 70 of the color filter substrate 60. In order to prevent the liquid crystal 90 from leaking and maintain the bonded state of the two substrates, a seal pattern 85 surrounding the display area AA is provided along the second black matrix 63b formed on the color filter substrate.

  On the array substrate 11, the gate pad area GPA and the data pad area DPA are located in a non-display area outside the seal pattern 85.

  A gate pad and a data pad are located in the gate pad area GPA and the data pad area DPA, respectively. The gate pad includes a gate pad electrode 52 and a gate pad electrode terminal 52. The data pad includes a data pad electrode (not shown) and a data pad electrode terminal 54.

  The gate pad and the data pad are connected to a PCB (Printed Circuit Board) having a drive circuit by a TCP (Tape Carrier Package) film. A gate driver GD or a data driver is positioned on the TCP film.

  The connection part 80 at one end of the TCP film is in contact with the gate pad or the data pad, that is, the gate pad electrode terminal 52 or the data pad electrode terminal 54.

  A protective film 87 is further formed as a sealing material on the connection part 80 that contacts the gate pad and the data pad as a sealing material so that the contact between the TCP film and the array substrate 11 is not separated.

  In the liquid crystal display device having the above-described structure, a thermosetting or ultraviolet curable epoxy or acrylic series is used as the material for forming the sealing pattern 11 for sealing the substrates 11 and 61 and the protective film on the top of the TCP film. Substances are used. In addition, the space between the upper and lower substrates 11 and 61 of the liquid crystal display device, that is, the patterned spacer 56 and the ball spacer for maintaining the cell gap are also thermosetting or ultraviolet curable epoxy, Acrylic materials are used.

  However, when the seal pattern 85, the protective film 87, and the patterned spacer 56 are formed using an epoxy or acrylic material, there is a problem that the seal pattern is frequently ruptured by heating and the defect rate increases. is there.

  Recently, efforts have been made to minimize manufacturing costs in order to improve the productivity of liquid crystal display devices, and new materials with improved performance and reduced costs compared to existing products have been sought. ing.

  The present invention uses a frit glass or glass paste as a new material having relatively low material costs and excellent properties, and is used as a sealing material or a sealing material for a liquid crystal display device. Forming patterned spacers with the material to maintain the cell gap reduces material costs and costs and increases productivity.

In order to achieve the above-described object, the present invention provides a first substrate and a second substrate facing each other; a liquid crystal layer positioned between the first substrate and the second substrate; the first substrate and the second substrate; Provided is a liquid crystal display device including a seal pattern positioned between substrates, surrounding the liquid crystal layer, and formed of frit glass or glass paste.
Here, the frit glass includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, a filler, and a binder material. The glass paste includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, and a bonding material.

A first substrate and a second substrate facing each other; a liquid crystal layer having a cell gap positioned between the first substrate and the second substrate; and positioned between the first substrate and the second substrate, A liquid crystal display device including a spacer formed of frit glass or glass paste while maintaining a cell gap is provided.
Here, the frit glass includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, an extender, and a bonding material. The glass paste includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, and a bonding material.

Furthermore, the present invention is located at a peripheral portion of the substrate, and contacts with either the gate pad or the data pad to connect the gate pad and the data pad; and the driving circuit and the gate pad or the data pad. There is provided a liquid crystal display device comprising: a connecting portion that covers; a contact region between one of the gate pad and the data pad and the connecting portion; and a protective film formed of frit glass or glass paste.
Here, the frit glass includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, an extender, and a bonding material.
The glass paste includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, and a bonding material.

On the other hand, using either a syringe or a dispenser, applying either frit glass or glass paste along the periphery of the first substrate to form a seal pattern; A method for manufacturing a liquid crystal display device, comprising: bonding a first substrate to cure the seal pattern; and injecting liquid crystal between the first substrate and the second substrate surrounded by the seal pattern. To do.
Here, the frit glass includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, an extender and a bonding material, and a seal pattern formed of the frit glass has a temperature of 300 to 500 ° C. Cured.

The glass paste includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, and a bonding material, and the seal pattern formed of the glass paste is cured at 400 to 900 ° C.

  Forming a black matrix on the display area of the first substrate; using either a syringe or a dispenser, either frit glass or glass paste so as to correspond to the black matrix, Applying to one of the first substrate and the second substrate to form a spacer; curing the spacer; and bonding the first substrate and the second substrate to form the first substrate and the second substrate; And a liquid crystal display device manufacturing method including a step of injecting liquid crystal between the substrates.

Here, the frit glass includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, an extender and a bonding material, and a seal pattern formed of the frit glass has a temperature of 300 to 500 ° C. Cured.

The glass paste includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, and a bonding material, and the seal pattern formed of the glass paste is cured at 400 to 900 ° C.

  And forming a gate pad and a data pad on a peripheral portion of the substrate; and connecting a driving circuit and any one of the gate pad and the data pad to connect the gate pad and the data pad. A method of manufacturing a liquid crystal display device, the method comprising: forming a protective film covering either the gate pad or the data pad and the contact area of the connecting portion by applying either frit glass or glass paste I will provide a.

Here, the frit glass includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, an extender, and a bonding material. Cured.

The glass paste includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, and a bonding material, and the seal pattern formed of the glass paste is cured at 400 to 900 ° C.

  Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings.

  In the liquid crystal display device of the present invention, the seal pattern is formed using frit glass or glass paste, thereby preventing the seal pattern from rupturing when heated.

  In addition, by using frit glass or glass paste to form a patterned spacer to maintain the cell gap, cell gap defects due to crushing due to increased hardness can be prevented. Can be handled relatively easily.

  In addition, the protective film formed on the top of the TCP film connected to the gate pad and the data pad is stable by forming a frit glass or glass paste having high hardness and excellent thermal stability. Maintain a healthy state.

  The composition and characteristics of the frit glass or glass paste used in the liquid crystal display device of the present invention will be described.

The main component of the frit glass is lead oxide PbO, and the subcomponents include zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, extender and bonding material. The frit glass is used as a seal pattern, a protective film, and a spacer for bonding glass substances by heating and baking at 300 to 500 ° C. in a state where an organic solvent is mixed.

Further, the glass paste includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, and a bonding material, and is a seal pattern for bonding a glass material by heating and baking at 400 to 900 ° C. Used as protective film and spacer. At this time, the characteristics of the glass paste will be described. The thermal expansion coefficient of the glass paste is 100 * 10 ⁻⁷ / ° C. at the maximum, the insulation resistance is about 10 ¹² Ω, and the density is 2 g / cm ^3. Or 6 g / cm ³ . Furthermore, the bending strength is a maximum of 40 MPa.

  The frit glass and glass paste having such composition and physical properties are very similar to the material forming the glass itself, and the adhesive material is used as a seal pattern material for sealing or joining the glass substrate. Is excellent. In particular, since a substrate used in a liquid crystal display device uses a glass material, no material reaction occurs during the formation process of the liquid crystal display device. Further, there is no phenomenon such as discharge of impurities in contact with the liquid crystal. Accordingly, forming some components of the liquid crystal display device with frit glass and glass paste has many advantages.

  By mixing an organic solvent into the frit glass described above, it becomes a paste like glass powder. By applying such a paste-like frit glass or glass paste to a desired portion on a substrate using a syringe or a dispenser, and baking the applied frit glass or glass paste at a predetermined temperature. It can be used as a sealing material or a sealing material.

  FIG. 3 is a view illustrating a process of forming a seal pattern on a substrate for a liquid crystal display device using a frit glass or glass paste according to an embodiment of the present invention.

  In the liquid crystal display device, the seal pattern 115 serves as a means for bonding and fixing the array substrate and the color filter substrate facing each other to maintain the cell gap at the frame portion of the both substrates. The substrate 100 in FIG. 3 corresponds to either the array substrate or the color filter substrate.

  At this time, the seal pattern 115 needs to be formed of a substance that does not react with the liquid crystal by directly contacting the liquid crystal filling the inside of the display area for displaying the screen. Further, since the array substrate and the color filter substrate must be firmly fixed, it is necessary to form the substrate with a material having an excellent adhesion to the substrate.

  As a material that satisfies all these important characteristics, conventionally, an epoxy or acrylic group material is used to form a seal pattern. However, an epoxy or acrylic group material has a high unit price and costs. It is an obstacle to save. Therefore, in the present invention, the unit price is lower than that of epoxy or acrylic series, and it does not form impurities even when it reacts with liquid crystal, and uses frit glass or glass paste that has excellent adhesion to the substrate 100, and seals. A pattern 115 is formed. Accordingly, at the same time as the cost saving, a more excellent sealing state is maintained as compared with a seal pattern formed of an epoxy or acrylic material.

  Further, by forming the seal pattern 115 using frit glass or glass paste, the seal pattern 115 is cured after the seal pattern 115 is applied. Since the seal pattern 115 itself is made of a material that is almost similar to glass, the seal pattern 115 is hardened firmly, and thereafter, the seal pattern hardly ruptures depending on the temperature.

A method for forming the seal pattern 115 will be briefly described.
As shown in FIG. 3, the seal pattern 115 is filled in the syringe 110 with paste type frit glass or glass paste. Thereafter, the frit glass or glass paste is dispensed while the syringe 110 is continuously moved along the peripheral portion of the substrate 100 to form the seal pattern 115. Instead of the syringe 110, other application devices such as a dispenser can be used. The substrate 100 is an array substrate including a thin film transistor (not shown) and a pixel electrode (not shown), or a color filter substrate including a color filter pattern and a common electrode.

  The substrate 100 on which the seal pattern 115 is formed and the substrate facing the substrate 100 are bonded using the seal pattern 115. Then, liquid crystal is injected between the two substrates to cure the seal pattern 115, thereby completing a liquid crystal display device (not shown). At this time, the curing temperature is 300 to 500 ° C. for the frit glass and 400 to 900 ° C. for the glass paste.

  FIG. 4 is a diagram illustrating a process of forming a patterned spacer on a substrate for a liquid crystal display using a frit glass or glass paste according to another embodiment of the present invention.

  The formation of the patterned spacer using the frit glass or glass paste according to another embodiment of the present invention is characterized in that a dispenser or a syringe 220 is used as in the above-described embodiment. In FIG. 4, the substrate 200 is a color filter substrate. However, an array substrate can also be used.

  In forming the patterned spacer 215, a number of syringes 220 (or dispensers) are arranged at regular intervals. One end of the syringe 220 dispenses frit glass or glass paste in units of micro micrometers.

  Further, unlike the formation of the seal pattern, the frit glass or the glass paste is dispensed by moving at a predetermined interval as if in a dot shape. As a result, the patterned spacers 215 are formed at regular intervals on the upper side of the black matrix 210 formed surrounding the pixels P that display a predetermined area on the substrate 200, for example, red R, green G, and blue B, for example. .

  The substrate 200 on which the patterned spacer 215 is dispensed is baked. Baking is performed at 300 to 500 ° C. for frit glass and at 400 to 900 ° C. for glass paste for 5 to 30 minutes. This completes the patterned spacer 215 in a cured state. At this time, the patterned spacer 215 may be formed for each of a large number of pixels P without being formed for each pixel P. In this case, the separation interval is constant.

  When forming different cell gaps depending on the liquid crystal display model, the amount of the patterned spacer 215 is adjusted by adjusting the amount of frit glass or glass paste applied using the syringe 220 (or dispenser). The height can be adjusted easily. Therefore, there is an advantage that it is easy to deal with various models.

  Due to the characteristics of the organic insulating material, the conventional patterned spacer is subjected to severe external pressure after the liquid crystal display device with low hardness is completed. As a result, poor image quality is caused. However, the formation of patterned spacers using frit glass similar to glass or glass paste makes it difficult to maintain the cell gap due to crushing due to the characteristics of frit glass or glass paste that is resistant to strength and heat changes. Etc. can be prevented.

  In the other embodiments described above, the patterned spacer 215 is formed on a color filter substrate for a liquid crystal display device. However, the patterned spacer may be formed on the array substrate. At this time, the formation position of the patterned spacer is formed on the gate wiring, data wiring, and thin film transistor corresponding to the black matrix. The patterned spacer can contact the common electrode or the overcoat layer depending on the model in the color filter substrate, and can contact the protective layer in the array substrate.

On the other hand, although not shown in the above-mentioned drawings, frit glass or glass paste is used as a protective film that covers a portion where the gate pad and data pad of the array substrate are in contact with the connecting portion of the TCP film.
Further, when a gate driver or data driver IC is directly mounted on a substrate without using a COG (Chip On Glass) type liquid crystal display device, that is, a TCP film, the IC formed on the substrate is covered. As the protective film, frit glass or glass paste is used.

  In this case, the epoxy or acrylic material used as an existing sealing material has better adhesive strength and higher hardness, and thus plays a role as a sealing material more stably.

  The present invention is not limited to the above-described embodiments, but can be applied and applied in various ways.

It is sectional drawing which showed the conventional liquid crystal display device schematically. It is sectional drawing shown along the II-II line of FIG. FIG. 5 is a view illustrating a process of forming a seal pattern on a substrate for a liquid crystal display device using frit glass or glass paste according to an embodiment of the present invention. FIG. 6 is a view illustrating a process of forming a patterned spacer on a substrate for a liquid crystal display using a frit glass or glass paste according to another embodiment of the present invention.

Explanation of symbols

100: Array substrate 110: Syringe 115: Seal pattern

Claims (18)

A first substrate and a second substrate facing each other;
A liquid crystal layer positioned between the first substrate and the second substrate;
A liquid crystal display device comprising a seal pattern positioned between the first substrate and the second substrate and surrounding the liquid crystal layer and formed of frit glass or glass paste. _2. The liquid crystal display device according to claim 1, wherein the frit glass includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, an extender, and a bonding material. The liquid crystal display device according to claim 1, wherein the glass paste includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, and a bonding material. A first substrate and a second substrate facing each other;
A liquid crystal layer positioned between the first substrate and the second substrate and having a cell gap;
A liquid crystal display device comprising a spacer, which is located between the first substrate and the second substrate, maintains the cell gap, and is formed of frit glass or glass paste. 5. The liquid crystal display device according to claim 4, wherein the frit glass includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, an extender, and a bonding material. 5. The liquid crystal display device according to claim 4, wherein the glass paste includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, and a bonding material. A gate pad and a data pad located at the periphery of the substrate;
A connecting portion that contacts either the gate pad or the data pad to connect the driving circuit to any one of the gate pad and the data pad;
A liquid crystal display device comprising a protective film made of frit glass or glass paste, covering a contact region between one of the gate pad and the data pad and the connecting portion. The liquid crystal display device according to claim 7, wherein the frit glass includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, an extender, and a bonding material. The liquid crystal display device according to claim 7, wherein the glass paste includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, and a bonding material. Applying either frit glass or glass paste along the periphery of the first substrate using either a syringe or dispenser to form a seal pattern;
Bonding the second substrate and the first substrate to cure the seal pattern;
A method of manufacturing a liquid crystal display device, comprising the step of injecting liquid crystal between the first substrate and the second substrate surrounded by the seal pattern. The frit glass includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, an extender and a bonding material, and the seal pattern formed of the frit glass is cured at 300 to 500 ° C. The method of manufacturing a liquid crystal display device according to claim 10. The glass paste includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, and a bonding material, and the seal pattern formed of the glass paste is cured at 400 to 900 ° C. A method for manufacturing a liquid crystal display device according to claim 10. Forming a black matrix in the display area of the first substrate;
Using either a syringe or a dispenser, either frit glass or glass paste is applied to either the first substrate or the second substrate so as to correspond to the black matrix to form a spacer. And the stage of
Curing the spacer;
Bonding the first substrate and the second substrate, and injecting liquid crystal between the first substrate and the second substrate. The frit glass includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, an extender and a bonding material, and the seal pattern formed of the frit glass is cured at 300 to 500 ° C. The method for manufacturing a liquid crystal display device according to claim 13. The glass paste includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, and a bonding material, and the seal pattern formed of the glass paste is cured at 400 to 900 ° C. A method for manufacturing a liquid crystal display device according to claim 13. Forming gate pads and data pads on the periphery of the substrate;
Forming a connecting portion in contact with either the gate pad or the data pad to connect the driving circuit to the gate pad or the data pad;
A method of manufacturing a liquid crystal display device, comprising: applying a frit glass or a glass paste to form a protective film that covers a contact region between one of the gate pad and the data pad and the connecting portion. . The frit glass includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, an extender and a bonding material, and the seal pattern formed of the frit glass is cured at 300 to 500 ° C. The method of manufacturing a liquid crystal display device according to claim 16. The glass paste includes lead oxide PbO, zinc oxide ZnO, silicon oxide SiO ₂ , barium oxide BaO powder, and a bonding material, and the seal pattern formed of the glass paste is cured at 400 to 900 ° C. A method for manufacturing a liquid crystal display device according to claim 16.

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