KR0141766B1 - Manufacturing method of liquid crystal display elements - Google Patents

Abstract

The present invention relates to a method for manufacturing a liquid crystal display device, and a conventional liquid crystal display device forms a gate electrode, a pad electrode, a semiconductor layer, a pixel electrode, a source / drain electrode, and a protective insulating layer. Since the photo etching process is performed, there is a problem that the yield is reduced and the cost is increased. The present invention provides a liquid crystal display device manufacturing method to etch the protective insulating layer of the exposed pad electrode portion by wet etching or dry etching without using a mask after assembling the upper and lower panels to solve this problem.

Description

Liquid crystal display device manufacturing method

1 is a cross-sectional view of a conventional liquid crystal display device.

2 is a manufacturing process diagram for FIG.

3 is a cross-sectional view of a conventional thin film transistor array.

4 is a cross-sectional view of a liquid crystal display device of the present invention.

5 is a manufacturing process diagram of FIG.

* Explanation of symbols for the main parts of the drawings

21: Substrate 22: thin film transistor

23: pad electrode 24: protective insulating layer

25: black matrix 26: color filter

27: common electrode 28: alignment film

29: Room 30: Liquid crystal

31: Spacer

The present invention relates to a method for manufacturing a liquid crystal display device, and in particular, the protective insulating layer on the upper part of the thin film transistor substrate is etched without using a mask after assembling the upper and lower substrates, thereby increasing the yield and reducing the cost by simplifying the process. The present invention relates to a liquid crystal display device manufacturing method.

FIG. 1 is a cross-sectional structure diagram of a conventional liquid crystal display device. As shown therein, a gate electrode 2 and a pad electrode 3 are formed on a lower substrate 1 at regular intervals, and the pad electrode 3 is formed. A gate insulating film 4 is formed on the gate electrode 2 except for the above, and the semiconductor layer 5 and the doped semiconductor layer 6 are successively formed on the gate insulating film 4 and at predetermined intervals. (7) is formed, and a source / drain electrode 8 is formed on the doped semiconductor layer 6, and a protective insulating layer 9 is formed on the source / drain electrode 8 on the gate electrode 2 side. To form a lower panel, a black matrix 10 is formed on the upper substrate 1 ', a color filter 11 is formed on the black matrix 10, and a common electrode on the color filter 11. 12 is formed to form an upper panel, the liquid crystal ( 13) is injected, and when described with reference to Figure 2 attached to the manufacturing method thereof is as follows.

(A) to (g) of FIG. 2 are manufacturing process diagrams of a conventional liquid crystal display device, and as shown in FIG. 2 (a), a mask is formed by depositing a metal on the lower substrate 1 by sputtering. After patterning, the gate electrode 2 and the pad electrode 3 are formed, and then the gate insulating film 4 is coated on the entire surface of the device.

Thereafter, as shown in FIG. 2B, the semiconductor layer 5 and the doped semiconductor layer 6 are successively deposited on the gate insulating film 4, and then the semiconductor layer 5 and A pixel electrode 7 is formed on the gate insulating film 4 that forms a pattern of the doped semiconductor layer 6, deposits metal on the device, and then patterns the pattern using a mask to maintain a predetermined distance from the semiconductor layer 5. To form.

Subsequently, as shown in (c) of FIG. 2, metal is deposited and then patterned using a mask to form a source / drain electrode 8, and then the doped semiconductor layer 6 between the source / drain electrode 8. Then, the protective insulating layer 9 is applied to protect the thin film transistor (TFT) on the entire surface of the device.

Next, as shown in (d) of FIG. 2, a photoresist (PR) is applied on the protective insulating layer 9, and then only a portion of the pad electrode 3 is exposed and etched by a photoetching process using a mask. By removing the protective insulating layer 9 on the pad electrode 3 to complete the lower panel as shown in (e) of FIG.

Further, as shown in FIG. 2 (f), a black matrix 10 is formed on the upper substrate 1 'to block light. As shown in FIG. 2 (g), the color filter 11 is formed on the black matrix 10. As shown in FIG. After forming a common electrode 12 is deposited on the front surface of the device to complete the upper panel.

Thereafter, the lower panel and the upper panel were bonded together as shown in FIG. 1, and then the liquid crystal 13 was injected through the liquid crystal inlet to manufacture the liquid crystal display device.

In the conventional liquid crystal display device manufactured as described above, the pad electrode 3 is connected to the gate line 14 and the data line 15 to be in contact with the driving element as shown in the planar structure diagram of the thin film transistor array of FIG. The thin film transistor array (TFT Array) is driven.

However, in the conventional liquid crystal display device manufactured as described above, however, the gate electrode 2, the pad electrode 3, the semiconductor layers 5 and 6, the pixel electrode 7, the source / drain electrode 8, and the protective insulating layer (9) Since the photo-etching process using the mask is performed when the pattern is formed, there is a problem that the yield is reduced and the cost is increased.

In order to solve the above problems, the present invention provides a method of manufacturing a liquid crystal display device in which the protective insulating layer of the pad electrode portion exposed after assembling the upper and lower panels is etched by wet etching or dry etching without using a mask. There is a purpose.

The present invention provides a process of rubbing by forming an alignment layer only on a thin film transistor array and a color filter array part on a lower panel on which a thin film transistor is manufactured and an upper panel on which a color filter is formed, and a thread outside the liquid crystal inlet part of the upper panel. Forming and dispersing spacers in the lower panel, bonding and hardening the upper and lower panels, removing a portion of the upper panel for tapping with a driving element, and liquid crystal through a liquid crystal inlet. After the injection, the liquid crystal injection hole is sealed, and the protective insulating layer of the lower panel is configured to be etched.

In addition, the present invention is a rubbing process of forming an alignment layer on the thin film transistor array and the color filter array portion of the upper panel and the lower panel is a thin film transistor having a pad portion and the color filter is formed, and except the liquid crystal inlet portion of the upper panel Forming a seal on the outside of the array and dispersing the spacers on the lower panel, bonding and curing the upper and lower panels, and removing a portion of the upper panel for tapping with the driving element; And a process of etching the protective insulating layer on the pad of the lower panel and injecting the liquid crystal through the liquid crystal inlet, and then encapsulating the liquid crystal inlet. The following description will be made in detail with reference to the accompanying drawings. same.

4 is a cross-sectional structure diagram of a liquid crystal display device according to the present invention. A thin film transistor 22 and a pad electrode 23 are formed on the lower substrate 21 at regular intervals, and the pad electrode 23 is formed. A protective insulating layer 24 and an alignment layer 28 are sequentially formed on the thin film transistor 22 except for the lower panel, and a black matrix 25 is formed on the upper substrate 21 ′. A color filter 26 is formed on the color filter 25, and a common electrode 27 and an alignment layer 28 ′ are sequentially formed on the color filter 26 to form an upper panel, and the lower panel and the upper panel are bonded to each other. In addition, the liquid crystal 30 is injected between both panels to be bonded, and the seal 29 is configured to maintain the gap between the panels at both sides, which will be described with reference to FIG. .

5A to 5E are manufacturing process diagrams of the liquid crystal display device of the present invention. As shown in FIG. 5A, first, a thin film transistor 22 is formed on the lower substrate 21 by using a generally known technique. ) And a pad electrode 23, and then a protective insulating layer 24 for protecting the thin film transistor is applied to the front surface of the device (Fig. 5A) and black on the upper substrate 21 '. The matrix 25 and the color filter 26 are sequentially formed, and then a common electrode 27 is deposited on the front surface of the device ((A-2 in FIG. 5).

Next, as shown in (b) of FIG. 5, the alignment films 28 and 28 ', which are polymer materials, are coated on the thin film transistor array and the color filter array, respectively, on the lower panel and the upper panel as described above. Then rubbing to form a groove in one direction.

Subsequently, as shown in (c) of FIG. 5, the lower panel spreads a transparent spacer 31 having a diameter of about 4 to 6 μm on the alignment layer 28 ((c-1 of FIG. 5)).

At this time, the spacer 31 maintains the width of the liquid crystal by maintaining a gap when the upper and lower panels are bonded.

On the other hand, the upper panel forms a seal 29 of about 1 to 5 mm using a seal mask outside the array ((C-2 of FIG. 5)).

At this time, the seal 29 is not formed in the liquid crystal inlet portion for injecting the liquid crystal.

Subsequently, as shown in FIG. 5E, the upper and lower panels are bonded and cured using a bonding machine, and then the pad electrode 23 portion of the pad electrode 23 is formed for the tab Automated Bonding (TAB) of the driving device. Part of the upper panel is removed to form a desired liquid crystal cell, and then the liquid crystal 30 is continuously injected between the two panels through the liquid crystal inlet. Then, the liquid crystal inlet is sealed with an end seal, and then the pad electrode ( To expose 23), the protective insulating layer 24 on the pad electrode 23 is removed by using wet etching or dry etching as shown in FIG.

In this case, when the protective insulating layer 24 is removed by wet etching, HF, BHF, or the like is used as an etchant, and the etching time is about 30 seconds to 2 minutes depending on the concentration of the etching solution. At this time, the protective insulating layer 24 to be etched includes a silicon nitride film (SiN _x ), a silicon oxide film (SiO _x ), or the like deposited by a plasma chemical vapor deposition (PECVD) method.

On the other hand, when the protective insulating layer 24 is removed by dry etching, the protective insulating layer 24 may be etched before the liquid crystal 30 is injected in the above process.

As a dry etching agent, a gas such as CF ₄ , SF ₆ , C ₂ ClF ₅ , and a mixed gas in which O ₂ , He, etc. are added to the gas are used.

In particular, SF ₆ + He is used as an optimal mixed gas because the substrate is glass and the protective insulating layer is silicon nitride (SiN _X ) because the selectivity to the substrate is excellent.

Meanwhile, when the present invention is applied to a large area (350 × 300 mm ² ), 12 sheets of 3 inch LCD panels may be formed on a large area substrate. Therefore, after joining the upper and lower panels, only the upper panel is cut first to remove unnecessary parts, and then the upper and lower pad electrodes of the lower panel are removed and etched using dry etching to complete the liquid crystal display device.

In addition, in the case of using wet etching, the liquid crystal display device is formed by encapsulating the injection hole through the liquid crystal injection hole and an end cell in order to prevent the etchant from penetrating into the liquid crystal injection hole.

As described above, the present invention has the effect of improving yield and cost reduction due to process simplification because the liquid crystal cell is etched without using a mask after assembly.

Claims (8)

Forming a rubbing layer on only the thin film transistor array and the color filter array portion on the lower panel where the thin film transistor having the pad portion is formed and the upper panel on which the color filter is formed; and a yarn outside the array except the liquid crystal inlet portion of the upper panel. Forming and dispersing spacers on the lower panel, bonding and hardening the upper and lower panels, removing a portion of the upper panel for tapping with the driving element, and liquid crystal through a liquid crystal inlet. The method of manufacturing a liquid crystal display device comprising the step of encapsulating the liquid crystal inlet after peeing and etching the protective thin layer on the pad of the lower panel. The method of claim 1, wherein the protective insulating layer is etched by a wet etching method. The method of claim 2, wherein HF, BHF, or the like is used as an etchant. The method of claim 1 or 2, wherein a silicon oxide film (SiO _X ), a silicon nitride film (SiN _X ), or a compound thereof is used as the protective insulating layer etched by the wet etching method. Forming a rubbing layer on only the thin film transistor array and the color filter array portion on the lower panel where the thin film transistor having the pad portion is formed and the upper panel on which the color filter is formed; and a yarn outside the array except the liquid crystal inlet portion of the upper panel. Forming and dispersing spacers in the lower panel, bonding and hardening the upper and lower panels, removing a portion of the upper panel for tapping with the driving element, and pads of the lower panel. And a step of etching the protective insulating layer on the phase, and then injecting the liquid crystal through the liquid crystal injection hole and then sealing the liquid crystal injection hole. The method of claim 5, wherein the protective insulating layer is etched by a dry etching method. The method of claim 6, wherein a gas such as CF ₄ , CF ₆ , SF ₆ , C ₂ ClF ₅ is used as an etchant. The liquid crystal display device manufacturing method according to claim 6, wherein a mixed gas obtained by adding O ₂ , He, etc. to a gas such as CF ₄ , CF ₆ , SF ₆ , C ₂ ClF _{5 is used} as an etchant.