KR20040036988A - Liquid crystal display device - Google Patents

Abstract

PURPOSE: An LCD device is provided to comprise a hole formed in cut structure between adjacent data output lines, and not to form a hole between broken parts of data lines, thereby improving open inferiority of a data pad link portion. CONSTITUTION: An upper substrate(90) disposes a color filter. A lower substrate(91) disposes a TFT. A liquid crystal layer is filled between the upper substrate(90) and the lower substrate(91). Many gate pads(92) and data pads(93) are formed along edge surfaces of the lower substrate(91). A data pad link portion("B") is connected to one of the data pads(93) in order to apply a driving signal to data lines of the lower substrate(91). A gate pad link portion is connected to the gate pads(92) so as to apply a driving signal to gate lines of the lower substrate(91).

Description

Liquid crystal display device

The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device that can improve the open failure of the data pad link portion.

As the information society develops, the demand for display devices is increasing in various forms.In recent years, liquid crystal display (LCD), plasma display panel (PDP), electro luminescent display (ELD), and vacuum fluorescent display (VFD) have been developed. Various flat panel display devices have been studied, and some are already used as display devices in various devices.

Among them, LCD is the most widely used as a substitute for CRT (Cathode Ray Tube) for the use of mobile image display device because of the excellent image quality, light weight, thinness, and low power consumption, and mobile type such as monitor of notebook computer. In addition, it is being developed in various ways, such as a television for receiving and displaying broadcast signals, and a monitor of a computer.

As described above, although various technical advances have been made in order for the liquid crystal display device to serve as a screen display device in various fields, the task of improving the image quality as the screen display device has many advantages and disadvantages.

Therefore, in order to use a liquid crystal display device in various parts as a general screen display device, the key to development is how much high definition images such as high definition, high brightness, and large area can be realized while maintaining the characteristics of light weight, thinness, and low power consumption. It can be said.

Such a liquid crystal display device may be broadly divided into a liquid crystal panel displaying an image and a driving unit for applying a driving signal to the liquid crystal panel, wherein the liquid crystal panel includes first and second glass substrates having a space and are bonded to each other; It consists of a liquid crystal layer injected between the said 1st, 2nd glass substrate.

The first glass substrate (TFT array substrate) may include a plurality of gate lines arranged in one direction at a predetermined interval, a plurality of data lines arranged at regular intervals in a direction perpendicular to the gate lines, and A plurality of pixel electrodes formed in a matrix form in each pixel region defined by crossing each gate line and data line, and a plurality of thin films that transmit signals of the data line to each pixel electrode by being switched by signals of the gate line The transistor is formed.

The second glass substrate (color filter substrate) includes a black matrix layer for blocking light in portions other than the pixel region, an R, G, B color filter layer for expressing color colors, and a common electrode for implementing an image. Is formed. Of course, the common electrode is formed on the first glass substrate in the transverse electric field type liquid crystal display device.

The first and second glass substrates are bonded by an actual material having a predetermined space and a liquid crystal injection hole by a spacer, and a liquid crystal is injected between the two substrates.

In this case, in the liquid crystal injection method, the liquid crystal is injected between the two substrates by osmotic pressure when the liquid crystal injection hole is immersed in the liquid crystal container by maintaining the vacuum state between the two substrates bonded by the reality. When the liquid crystal is injected as described above, the liquid crystal injection hole is sealed with a sealing material.

1 is a schematic diagram illustrating a general liquid crystal display device.

As shown in FIG. 1, a pixel region 12 for displaying an image and driver ICs 10 and 11 for generating an image signal are provided, and a plurality of gate lines 14 and The plurality of data lines 16 cross each other to form a matrix, and the thin film transistor 13 is formed at the crossing point.

Although not shown in the drawing, a common electrode and a color filter are formed on an opposing substrate facing the substrate on which the thin film transistor 13 is formed, and the liquid crystal display is configured in such a manner that liquid crystal is injected and sealed between the two substrates. do.

FIG. 2 is a cross-sectional view illustrating the thin film transistor of FIG. 1.

As shown in FIG. 2, a gate electrode 22 formed of a metal such as molybdenum (Mo) in a predetermined region on the glass substrate 21 and a front surface of the glass substrate 21 including the gate electrode 22 are formed. The semiconductor layer 24, the ohmic contact layer 25, and a source electrode 26 made of metal such as chromium or molybdenum are formed on the gate insulating film 23 formed and the gate insulating film 23 on the gate electrode 22. And a drain electrode 27 are formed.

The passivation layer 28 is formed on the entire surface of the glass substrate 21 including the source electrode 26 and the drain electrode 27, and is electrically connected to the drain electrode 27 through the passivation layer 28. It consists of the pixel electrode 29 formed.

Here, the gate electrode 22 is connected to the gate line 14 of FIG. 1, the source electrode 26 is connected to the data line 16, and the drain electrode 27 is connected to the data line 16. The pixel electrode 29 is in contact with the pixel electrode 29 formed in the region surrounded by the gate line 14.

In the thin film transistor having the above structure, when a data voltage is applied to the gate electrode 22 through the gate line 14, the signal voltage flowing through the data line 16 is transferred from the source electrode 26 to the drain electrode 27. It operates to be applied through the ohmic contact layer 25 and the semiconductor layer 24.

When a signal voltage is applied to the source electrode 26, a voltage is applied to the pixel electrode 29 connected to the source electrode 26, thereby generating a voltage difference between the pixel electrode 29 and the common electrode.

Due to the voltage difference between the pixel electrode 29 and the common electrode, the molecular arrangement of the liquid crystal interposed therebetween changes, and since the molecular arrangement of the liquid crystal is changed, the light transmittance of the pixel changes, so that the data voltage is applied to the pixel. And color difference between pixels not applied. The color difference is used to control the screen of the display device.

Meanwhile, the liquid crystal display module is classified into a tape automated bonding (TAB) mounting method and a chip on glass (COG) mounting method according to a mounting method of a driving drive IC.

The TAB mounting method refers to a task of connecting a tape carrier package (TCP) with a drive driver IC to an LCD panel and a PCB. The connection process between TCP and LCD panels uses anisotropic conductive film instead of lead, depending on the specificity of the glass and metal material and the fixation of the pitch of about 0.2 mm or less. The process is connected using lead.

In contrast, the COG mounting method directly mounts the drive driver IC in the gate area and the data area of the LCD panel to transmit an electrical signal to the LCD panel. Usually, the anisotropic conductive film is used to adhere the drive drive IC to the LCD panel. .

On the other hand, in the COG type liquid crystal display device, a LOG (Line On Glass) method of forming a conductor on a lower substrate is used to apply a signal to each driving drive IC.

3 is a structural cross-sectional view of a general COG type liquid crystal display device.

As shown in FIG. 3, the upper substrate 101, the lower substrate 102, a printed circuit board (PCB) substrate 103, a flexible printed circuit (FPC) 104, and a data transmission cable 105 are formed. .

Although not shown, a polarizer is attached to one surface of the upper substrate 101, and a color filter and a common electrode are formed on the opposite surface of the upper substrate 101.

The lower substrate 102 has a larger area than the upper substrate 101 and is not shown in the drawing, but a polarizer is attached to one surface thereof.

In addition, an opposite surface to which the polarizer of the lower substrate 102 is not attached is configured to face the common electrode of the upper substrate 101, and includes a gate driving IC 106, a data driving IC 107, and a gate perpendicular to each other. Line 108 and data line 109.

The data driver IC 107 receives various input signals generated from the driver circuit of the PCB substrate 103.

In this case, the data line driving input wiring 110 through which the input signal flows is connected to the FPC 104 and the data driving IC 107, and the output wiring 111 of the data driving IC 107 is the data line 109. Make a one-to-one connection with each line of).

The gate driving IC 106 receives the gate input signal of the driving circuit of the PCB substrate 103 from the FPC 104 through the gate driving input wiring 110 to generate and output a gate voltage for driving the liquid crystal display device. Output to the terminal.

At this time, the output terminal of the gate driving IC 106 makes one-to-one connection with each line of the gate line 108 through the gate output wiring 112.

The data transmission cable 105 is installed to connect the PCB substrate 103 and the FPC 104 in order to apply a signal generated in the driving circuit of the PCB substrate 103 to the input wiring 110 of the data driving IC. do. That is, the signal generated by the driving circuit of the PCB substrate 103 is applied to the data driving input wiring 110 of the FPC 104 via the data transmission cable 105.

However, the LCD according to the related art requires a large amount of the FPC 104. This is because the width of the FPC 104 should be wide so that the input wirings 110 respectively connected to the input terminals of the driving ICs 106 and 107 are not shorted to each other.

Thus, a so-called LOG (Line On Glass) structure in which the data driver IC 107 and the input wiring 110 of the gate driver IC 106 are formed directly on the lower substrate 102 in order to reduce the usage of the FPC 104. A liquid crystal display device having a has also been developed.

4 is a diagram illustrating a COG type liquid crystal display device in which a general input wiring is directly mounted on a substrate.

As shown in FIG. 4, the circuit board includes a PCB substrate 103, an FPC 104 having a transmission line, an upper substrate 101, and a lower substrate 102.

The lower substrate 102 may include an input wiring 114 of a gate driving IC mounted directly on the lower substrate 102, an input wiring 113 of a data driving IC mounted directly on the lower substrate 102, and a common voltage wiring (not shown). And the gate driver IC 106, the data driver IC 107, the gate line 108, and the data line 109.

A common electrode is formed on the upper substrate 101. Although not shown, the common electrode is connected to the common voltage line of the lower substrate 102.

The general liquid crystal display shown in FIG. 4 has a structure in which various input signals necessary for driving the liquid crystal display are generated in the driving circuit of the PCB substrate 103, and the input signals are input to the transmission line of the FPC 104.

Each transmission line of the FPC 104 makes one-to-one connection with the input wiring 114 of the gate driving IC mounted directly on the lower substrate 102 and the input wiring 113 of the data driving IC.

The input signals applied to the input wirings 113 and 114 are input signals of the gate driving IC 106 and the data driving IC 107, and the output signals of the driving ICs 106 and 107 are the gate lines 108 and the data lines. 109 is applied. The liquid crystal display is driven according to the signals of the gate line 108 and the data line 109 to which the output signal is applied.

Hereinafter, a conventional liquid crystal display device will be described with reference to the accompanying drawings.

5 is a schematic plan view of a liquid crystal display according to the related art.

6 is an enlarged plan view of an output wiring of the LCD according to the related art of FIG. 5, and FIG. 7 is a structural cross-sectional view taken along line II ′ of FIG. 6.

8A and 8B are cross-sectional views illustrating structural problems according to the prior art along the line II ′ of FIG. 6.

The LCD according to the related art has an upper substrate 50 and a lower substrate 60 bonded together as shown in FIG. 5, a gate pad 70 and a data pad 80 formed on the lower substrate 60. And a data pad link portion 'A' connected to the data pad 80 to apply a driving signal to a data line (not shown) of the lower substrate 60 and a gate line (not shown) of the lower substrate 60. ) And a gate pad link unit connected to the gate pad 70 to apply a driving signal.

Hereinafter, the structure of the data pad link unit 'A' for transferring each signal coming through the data pad 80 from the data pad 80 in the liquid crystal display according to the related art having the above configuration will be described. Let's do it.

As illustrated in FIGS. 6 and 7, the data pad link unit 'A' includes a gate insulating layer 61 on the entire lower substrate 60, and a plurality of data output lines on the gate insulating layer 61. A 62 is formed, and a protective film 63 made of an organic insulating material such as benzocyclobutene (BCB) is formed over the lower substrate 60 including the plurality of data output lines 62, and the neighboring data output. Holes 64 are formed between the lines 62.

Although not shown in the drawing, the transparent electrode of the liquid crystal panel extends to the data pad link portion 'A' and the gate pad link portion.

The data output line 62 is formed of molybdenum (Mo), and is bent at a predetermined angle. That is, the data output line 62 of the data pad link portion 'A' has a bent portion.

In this case, the reason why the data output line 62 is bent at a predetermined angle is to improve resolution.

In the curved portion of the data output line 62, as shown in FIG. 7, the distance between the data output line 62 and the hole 64 is very narrow, about 1.5 mu m.

The holes 64 formed between the data output lines 62 are integrally formed along the data output lines 62. The reason for forming the holes 64 is a transparent electrode extending from the pixel electrode in a subsequent process. (ITO: Indium-Tin-Oxide) to improve adhesion and to insulate the data output lines 62.

The data output line 62 is formed when the source / drain electrode and the data line of the thin film transistor of the lower substrate 60 are formed together, and the hole 64 is the pixel electrode and the drain electrode of the lower substrate 60. It is formed together when forming a contact hole for the connection therebetween.

However, since the margin between the data output line 62 and the hole 64 is very narrow at 1.5 占 퐉 in the bent portion of the data output line 62, the protective film 63 is etched to form a hole between the data output line 62. When forming 64, a phenomenon in which one side of the data output line 62 is exposed may occur as shown in FIG. 8A.

In addition, the exposed data output line 62 may be eroded by an etchant when the transparent electrode (not shown) is wet after the hole 64 is formed, thereby causing a data open phenomenon as illustrated in FIG. 8B.

The gate pad link unit has the same structure as the data pad link unit except that a plurality of gate output lines are formed on the lower substrate 60 in a curved structure instead of the data output line of the data pad link unit 'A'. Has

The present invention has been made to solve the above problems, and an object of the present invention is to provide a liquid crystal display device that can improve the open failure of the data pad link unit.

1 is a schematic configuration diagram showing a general liquid crystal display device

2 is a cross-sectional view illustrating the thin film transistor of FIG. 1.

3 is a structural cross-sectional view of a general COG type liquid crystal display device

4 is a diagram illustrating a general COG type liquid crystal display device in which input wiring is directly mounted on a substrate.

5 is a schematic plan view of a liquid crystal display according to the related art.

6 is an enlarged plan view of an output wiring of the LCD according to the related art of FIG. 5.

7 is a structural cross-sectional view taken along line II ′ of FIG. 6.

8A and 8B are cross-sectional views illustrating structural problems according to the prior art along the line II ′ of FIG. 6.

9 is a schematic plan view of a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 10 is an enlarged plan view of an output wiring of the liquid crystal display according to the exemplary embodiment of FIG. 9.

FIG. 11 is a cross-sectional view of a liquid crystal display device taken along lines II-II 'and III-III' of FIG.

Explanation of symbols on the main parts of the drawings

90: upper substrate 91: lower substrate

92: gate pad 93: data pad

94: gate insulating film 95: data output line

96: shield 97: hole

The liquid crystal display device of the present invention for achieving the above object comprises a gate insulating film formed on the entire lower substrate; A plurality of data output lines formed on the gate insulating film; A protective film formed on the lower substrate including the data output line; And a hole formed in a disconnected structure between the neighboring data output lines.

The data output line is formed with a bent portion.

The hole is disconnected between bends among the neighboring data output lines.

The data output line is made of any one of a metal such as chromium (Cr), molybdenum (Mo), titanium or tantalum, or a molybdenum alloy such as MoW, MoTa, or MoNo.

The protective layer may be an inorganic insulating material such as silicon nitride (Si 3 N 4) or silicon oxide (SiO 2), or an acrylic organic compound, Teflon, BCB (benzocyclobuten), Cytop, or PFCB (Perfluorocyclobutane). The dielectric constant of is composed of at least one of the small organic material.

A plurality of data pads are further disposed at the edge portion of the lower substrate.

The data output line is configured in a data pad link unit connecting the data pad and the data line of the lower substrate.

Hereinafter, a liquid crystal display according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

9 is a schematic plan view of a liquid crystal display according to an exemplary embodiment of the present invention.

FIG. 10 is an enlarged plan view of an output wiring of the liquid crystal display according to the exemplary embodiment of FIG. 9, and FIG. 11 is a cross-sectional view of the structure of the liquid crystal display along the lines II-II ′ and III-III ′ of FIG. 10. .

As shown in FIG. 9, the liquid crystal display of the present invention is filled between an upper substrate 90 having a color filter and a lower substrate 91 having a thin film transistor, and an upper substrate 90 and a lower substrate 91. A liquid crystal layer (not shown), a plurality of gate pads 92 and data pads 93 formed along edges of the lower substrate 91, and data lines (not shown) of the lower substrate 91. A data pad link portion 'B' connected to the data pad 93 to apply a driving signal, and a gate pad 92 to apply a driving signal to a gate line (not shown) of the lower substrate 91. It is composed of a connected gate pad link portion.

At this time, the upper substrate 90 (color filter substrate) includes a black matrix layer for blocking light in portions other than the pixel area, an R, G, and B color filter layer for expressing color colors, and a common image for implementing an image. An electrode is formed. Of course, in the transverse electric field type liquid crystal display device, the common electrode is formed on the lower substrate.

The lower substrate 91 (TFT array substrate) includes a plurality of gate lines arranged in one direction at a predetermined interval, a plurality of data lines arranged at regular intervals in a direction perpendicular to the gate lines, and A plurality of pixel electrodes formed in a matrix form in each pixel region defined by crossing each gate line and data line, and a plurality of thin films that transmit signals of the data line to each pixel electrode by being switched by signals of the gate line The transistor is formed.

In addition, the upper and lower substrates 90 and 91 have a predetermined space by a ball or column spacer.

The liquid crystal display according to the present invention having the above structure is characterized by a structure of the data pad link unit 'B' for transmitting a signal input through the data pad 93 to the data line of the lower substrate 91. .

As shown in FIGS. 10 and 11, the data pad link unit includes a gate insulating layer 94 formed on the entire lower substrate 91, and a plurality of data output lines 95 formed on the gate insulating layer 94. And a passivation layer 96 formed on an entire surface of the lower substrate 91 including the plurality of data output lines 95 and a hole 97 having a structure disconnected between the neighboring data output lines 95. Is formed.

Although not shown in the drawing, the transparent electrode of the liquid crystal panel extends to the data pad link portion 'B' and the gate pad link portion.

The transparent electrode is formed of one of indium tin oxide (ITO), indium zinc oxide (IZO), and indium tin oxide (ITZO).

The data output line 95 is formed of a metal such as chromium (Cr), molybdenum (Mo), titanium, or tantalum, or a molybdenum alloy (Mo alloy) such as MoW, MoTa, or MoNo, and has a predetermined angle. It has a structure of bending. That is, it is formed with a bent portion.

In this case, the reason why the data output line 95 is bent at a predetermined angle is to improve resolution.

In the curved portion of the data output line 95, the distance between the data output line 95 and the hole 97 is very narrow, as shown in FIG.

The hole 97 formed between the data output lines 95 is disconnected at the bent portion of the data output line 95, and is formed in an area between the data output lines 95 and the hole 97. The reason for forming a is to improve the adhesive strength of the transparent electrode extending from the pixel electrode in a subsequent process and to insulate the data output line 95.

The protective layer 96 may be formed of an inorganic insulating material such as silicon nitride (Si 3 N 4) or silicon oxide (SiO 2), or an acrylic organic compound, Teflon, BCB (benzocyclobuten), Cytop, or PFCB ( It is formed by selecting at least one of organic materials having a low dielectric constant such as perfluorocyclobutane.

The data output line 95 is formed when a source / drain electrode and a data line of the thin film transistor of the lower substrate are formed, and the hole 97 forms a contact hole for connection between the pixel electrode and the drain electrode of the lower substrate. When forming, it is formed by the transient etching process.

As described above, since the hole 97 is disconnected between the bent portions among the neighboring data output lines 95, the opening and erosion of the data line 95 are prevented in this portion. can do.

On the other hand, the present invention described above is not limited to the above-described embodiment and the accompanying drawings, it is possible that various substitutions, modifications and changes within the scope without departing from the technical spirit of the present invention. It will be apparent to those of ordinary skill in Esau.

The liquid crystal display of the present invention as described above has the following effects.

Since a hole is not formed between the bent portions of the data line of the data pad link portion, it is possible to prevent the problem that the data line is opened and thus eroded.

Claims (7)

A gate insulating film formed on the entire lower substrate; A plurality of data output lines formed on the gate insulating film; A protective film formed on the lower substrate including the data output line; And a hole formed in a structure disconnected between the neighboring data output lines. The method of claim 1, And the data output line has a bent portion. The method of claim 2, And the hole is disconnected between the bent portions of the data output line. The method of claim 1, And the data output line is made of a metal such as chromium (Cr), molybdenum (Mo), titanium, or tantalum, or a molybdenum alloy (Mo alloy) such as MoW, MoTa, or MoNo. The method of claim 1, The protective layer may be an inorganic insulating material such as silicon nitride (Si 3 N 4) or silicon oxide (SiO 2), or an acrylic organic compound, Teflon, BCB (benzocyclobuten), Cytop, or PFCB (Perfluorocyclobutane). A liquid crystal display device, characterized in that the dielectric constant of is composed of at least one of the small organic material. The method of claim 1, And a plurality of data pads further disposed at an edge portion of the lower substrate. The method of claim 6, And the data output line is configured in a data pad link unit connecting the data pad and the data line of the lower substrate.