JP2872128B2 - Liquid crystal display device and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device for preventing destruction due to static electricity during a manufacturing process and a method of manufacturing the same.

[0002]

2. Description of the Related Art As shown in FIG. 3, a TFT liquid crystal display device comprises a TFT substrate 1 and a counter substrate 8. T
An alignment film for aligning liquid crystal is formed on the surfaces of the FT substrate 1 and the counter substrate 8, and a sealant 9 for bonding the two substrates together and enclosing the liquid crystal 10 therein is formed in the peripheral portion. Both substrates are 5-6μ by the spacer between them
Liquid crystal 10 is filled at intervals of m. The transfer formed by the Ag paste 7 is for transmitting the voltage supplied to the TFT substrate 1 to the opposing substrate 8.

Next, a description will be given of a panel manufacturing process. T
The FT / opposite substrates are first cleaned, then 0.05-0.
An alignment film (polyimide) having a thickness of 1 μm is formed by flexographic printing. After firing this alignment film, rubbing is performed with a buff roll to give an alignment force of the liquid crystal. After cleaning by rubbing because dust adheres to the substrate surface, a pattern of the sealant 9 is formed on the TFT substrate by screen printing. Next, the transfer is formed by dispenser printing of the Ag paste 7 on the transfer electrode 3 at the corner. On the opposing substrate 8, spacers of 5 to 6 μm are scattered to keep the distance between the TFT and the opposing substrate constant.

[0004] The TFT substrate 1 on which the sealing agent 9 and the Ag paste 7 are printed and the opposing substrate 8 on which the spacers are scattered are superposed and then heated and fixed in a pressurized state. Fixed TF
The counter substrate is cut and separated into one panel. Thereafter, the liquid crystal 10 is vacuum-injected between the TFT and the counter substrate, and the injection hole is closed with a UV curable resin. Finally, a polarizing plate is attached to both sides to complete the panel.

After the sealing agent is screen-printed, the TFT substrate is charged when the sealing agent is peeled off from the printing stage. In addition, even during the transfer from the seal printing to the transfer printing, the toner is charged by contact with the transfer system. Therefore, when forming Ag paste 7 for transfer by dispenser printing,
Discharge occurs between the TFT substrate 1 and the dispenser 6.

[0006]

As described above, the conventional TF
A first problem in the manufacturing process of the T liquid crystal display device is that the internal elements of the TFT substrate are destroyed when applying a transfer Ag paste. The second problem is that the liquid crystal display element is contaminated. The reason is that the substrate is charged by transport from the previous process,
When applying the paste, a discharge occurs between the tip of the dispenser and the transfer electrode. The discharge causes the Ag paste, the constituent material of the transfer electrode, and the constituent material of the dispenser to scatter around, and at the same time, the internal elements of the TFT substrate are electrostatically damaged.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal display device capable of reducing display defects due to contamination and electrostatic destruction due to electrostatic discharge in a TFT substrate and improving productivity.

[0008]

According to the TFT liquid crystal display device of the present invention, a discharge electrode (4 in FIG. 1) connected via a transfer electrode and a resistor (5 in FIG. 2) is separated from an internal element as much as possible. Place it where you want. A for transfer electrode
Before applying the g paste, an Ag paste is applied to the discharge electrode, and all the electric charges on the substrate are dropped to the ground. Thereafter, an Ag paste is applied to the transfer electrode.

When applying the Ag paste to the discharge electrode,
All static electricity on the substrate drops to ground due to discharge.
At this time, since the discharge electrode and the transfer electrode are connected via a resistor, the internal elements of the TFT substrate are not destroyed. Further, at the time of discharging, the Ag paste, the constituent material of the transfer electrode, and the constituent material of the dispenser scatter around, but are not contaminated because the discharge electrode and the internal element are sufficiently separated.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the drawings. 1A and 1B are a cross-sectional view and a plan view showing a structure according to a first embodiment of the present invention. As shown, an internal element 2, a transfer electrode 3, a discharge electrode 4, and a resistor 5 are formed on a TFT substrate 1. Here, the transfer electrode 3 and the discharge electrode 4 are electrically connected via a resistor 5. The transfer electrode 3, discharge electrode 4, and resistor 5 are made of a TFT made of Cr
Of the wiring material. The thickness of the resistor 5 is reduced to increase the resistance. The discharge electrode 4 is formed at an end of the TFT substrate 1 as far away from the internal element 2 as possible.

Next, the manufacturing method according to the first embodiment will be described. The resistor 5 connecting the transfer electrode 3 and the discharge electrode 4 on the TFT substrate 1 is formed by half-etching the wiring formed simultaneously with the scanning line or the signal line in the photolithography step of forming the scanning line or the signal line of the TFT element. By doing so, the thickness is reduced.

The transfer electrode 3 is coated with a transfer Ag paste 7 for electrically connecting the TFT substrate 1 and the opposing substrate 8 with a dispenser 6.
In the present invention, it is applied to the transfer electrode 3 after being applied to the discharge electrode 4 in advance.

Next, the operation of the first embodiment of the present invention will be described in detail with reference to FIGS. 1 (a) and 1 (b). The TFT substrate 1 is charged by transport from the previous process. When a transfer paste is applied to the discharge electrode 4 by the dispenser 6, the electric charge on the TFT substrate 1 is discharged from the transfer electrode 3 via the resistor 5, the discharge electrode 4 is discharged to the dispenser 6, and the dispenser 6 is grounded. Run away to Subsequently, an Ag paste 7 for transfer is applied to the transfer electrode 3;
Since no charge remains on the T substrate 1, the dispenser 6
No discharge occurs between the transfer electrode 3 and the transfer electrode 3.

Next, a method of forming the resistor 5 will be described. T
Transfer electrode 3 and discharge electrode 4 when manufacturing FT element
Are formed in a pattern connecting. Next, the resistance 5 is formed by reducing the thickness by half-etching between the two electrodes. The pattern of the resistor 5 is formed of the same material (wiring material) as the transfer electrode and the discharge electrode.

Next, a second embodiment of the present invention will be described in detail with reference to the drawings. FIGS. 2A and 2B are a cross-sectional view and a plan view showing a structure according to a second embodiment of the present invention. As shown in FIG. 2, this embodiment has a two-layer structure including a transfer electrode 3, a discharge electrode 4, and a resistance (wiring material) 5 of a TFT and a transparent electrode material (ITO) 13 as a resistance. The resistance portion is thinned by half-etching. The operation of the second embodiment is the first operation.
The operation is the same as that of the embodiment. In this embodiment, when the transfer electrode, the discharge electrode, and the resistor are formed of a wiring material, even if a disconnection occurs due to a foreign substance or the like, there is an advantage that the disconnection is corrected by the next transparent electrode material.

[0016]

As described above, the first effect of the present invention is that the internal elements of the TFT substrate are not electrostatically damaged. This reduces the occurrence of electrostatic breakdown failure in the panel assembly process. The reason is that all the charges on the TFT substrate escape to the ground due to the discharge when the Ag paste is applied to the discharge electrode, and no discharge occurs when the Ag paste 7 is applied to the transfer electrode, so that the internal elements are not destroyed. Because. When the Ag paste is applied to the discharge electrode, a discharge occurs. However, since the internal element and the discharge electrode are connected via a resistor, the voltage is reduced and the element is not broken.

The second effect is that contamination of the internal elements due to the discharge is eliminated. This reduces the occurrence of defects due to contamination in the panel assembly process. The reason is,
The distance between the transfer electrode and the internal element is about 2 to 4 mm due to the limitation of the panel size. In the related art, the Ag paste, the transfer electrode, and the debris of the depenser are scattered to the internal element due to the discharge, which causes a failure. In the present invention, since the distance between the internal element and the discharge electrode is 30 mm or more, debris due to discharge does not scatter to the internal element. Therefore, there is no occurrence of defects due to contamination.

[Brief description of the drawings]

FIGS. 1A and 1B are a cross-sectional view and a plan view of a first embodiment of the present invention.

FIGS. 2A and 2B are a sectional view and a plan view of a second embodiment of the present invention.

FIGS. 3A to 3C are a plan view and a cross-sectional view of a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 TFT substrate 2 Internal element 3 Transfer electrode 4 Discharge electrode 5 Resistance 6 Dispenser 7 Ag paste 8 Counter substrate 9 Sealant 10 Liquid crystal

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G02F 1/136 G02F 1/1343 G02F 1/1345 G02F 1/13 101 G09F 9/30

Claims (2)

(57) [Claims] 1. A TFT substrate on which wiring of a pixel electrode arranged in a matrix and a TFT (= thin film transistor) for controlling signal supply to the pixel electrode is formed, and a counter substrate on which a counter electrode is formed. And a means for electrically connecting transfer electrodes formed on both the TFT substrate and the counter substrate with a conductive material, the liquid crystal being sealed with a gap between the two substrates by opposing the substrates. The liquid crystal display device has a discharge electrode electrically connected to a transfer electrode on the TFT substrate via a resistive film, and the discharge electrode is stored on the TFT substrate in a manufacturing process.
Used to discharge the accumulated charge through a dispenser
The liquid crystal display device, characterized in that that. 2. A resistive film connecting a transfer electrode and a discharge electrode is formed by half-etching a wiring formed at the same time as a scanning line or a signal line in a photolithographic step of forming a scanning line or a signal line of a TFT element. A method of manufacturing a liquid crystal display device.