KR20050094651A - Liquid crystal display and fabrication method thereof - Google Patents

Abstract

Disclosed are a liquid crystal display device and a method of manufacturing the same, which can prevent corrosion generated in a pad of a panel connected to an integrated circuit.

A liquid crystal display device according to the present invention includes a liquid crystal display panel comprising a first substrate, a second substrate, and liquid crystal injected between the first and second substrates; A pad unit formed in the non-display area when the display area and the non-display area are divided into one of the first and second substrates; And an integrated circuit mounted on the pad part to be electrically connected to generate a signal for operating the liquid crystal display panel, wherein the pad part includes a first area in which no contact hole is formed and a second area in which a contact hole is formed, A bump of the integrated circuit is attached to a first region where a contact hole is not formed.

Description

Liquid crystal display and manufacturing method thereof

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device and a method of manufacturing the same, which can prevent corrosion generated in a pad of a panel connected to an integrated circuit.

In today's information society, the role of electronic display devices becomes more and more important, and various electronic display devices are widely used in various industrial fields.

In general, an electronic display device refers to a device that transmits various pieces of information to a human through vision. That is, it is an electronic device that converts an electrical signal output from an electronic device, such as an electronic display device, into an optical signal recognizable by human vision, and may be referred to as a device that plays a role of bridging between humans and electronic devices.

Among such electronic display devices, a flat panel display device includes a cathode ray tube (CRT), a plasma display panel (PDP), a light emitting diode (LED), and an electroluminescent light. ELD (Electro Luminescent Display), Liquid Crystal Display (LCD).

Among the flat panel display devices currently developed, the liquid crystal display device is thinner and lighter than other display devices, has a low power consumption and a low driving voltage, and can be displayed close to the cathode ray tube. Is being used.

1 is a view schematically illustrating a general liquid crystal display panel. FIG. 2 is a view schematically illustrating a liquid crystal display device having a liquid crystal display panel of FIG. 1.

1 and 2, a liquid crystal display device includes a liquid crystal display panel 130 displaying an image and an integrated circuit 131 which generates an image signal and supplies the image signal to the liquid crystal display panel.

The liquid crystal display panel 130 may include a first substrate 100 (eg, an array substrate), a second substrate 102 (eg, a color filter substrate) attached to face the first substrate 100, and the first substrate 100. It is composed of a liquid crystal 114 injected between the substrate 100 and the second substrate 102.

A plurality of gate lines 104 and a plurality of data lines 106 are arranged in a matrix form on the first substrate 100, and pixel electrodes 108 and thin film transistors (TFTs) are formed at intersections thereof. 109 is formed.

On the second substrate 102, a color filter 112 and a transparent common electrode 110 made of RGB pixels in which a predetermined color is expressed while light passes through are formed.

As illustrated in FIG. 3, the TFT 109 may include a gate electrode 15 formed on the first substrate 100, a gate insulating layer formed on the gate electrode 15, and the first substrate 100. 25, an active layer 30 and an ohmic contact layer 35 formed on the gate insulating layer 25 on the gate electrode 15, and source / drain electrodes 40 and 45 formed on the active layer 30. It is composed of In addition, a passivation layer 50 made of an inorganic material or an organic material is formed on the first substrate 100 on which the TFT 109 is formed. A contact hole 80 is formed through the protective layer 50 to expose the drain electrode 45. Although not shown, contact holes exposing the gate terminal and the drain terminal of the pad region may also be formed through the protective layer 50.

The gate electrode 15 is connected to the gate line 104, and the source electrode 40 is connected to the data line 106. Therefore, when a scan voltage is applied to the gate electrode 15 through the gate line 104, a signal voltage flowing through the data line 106 is applied to the drain electrode through the source electrode 40 and the active layer 30. 45). When the signal voltage is applied to the drain electrode 45, a potential difference is generated between the pixel electrode 108 connected to the drain electrode 45 and the common electrode 110 of the second substrate 102. The molecular arrangement of the liquid crystal 114 injected between the electrode 108 and the common electrode 110 changes, so that a predetermined image is displayed as the light transmittance of the liquid crystal 114 changes. At this time, the TFT 109 serves as a switching element for operating the pixels of the liquid crystal display panel 130.

2, a gate pad portion 133 extending from the gate line 140 and a data pad portion 134 extending from the data line 106 are formed in the liquid crystal display panel 130. do.

In this case, the gate pad unit 133 is connected to one terminal of the gate integrated circuit 137 that generates the scan voltage, and the other terminal of the gate integrated circuit 137 is a flexible printed wiring board (FPC) (not shown). Circuit film, hereinafter referred to as FPC). In addition, the data pad unit 134 is connected to one terminal of the data integrated circuit 138 that generates a signal voltage, and the other terminal of the data integrated circuit 138 is connected to an FPC (not shown).

At this time, the gate pad unit 133 or the data pad unit 134 may be connected to the gate integrated circuit 137 or the data integrated circuit 138 in various ways. The electrodes of the integrated circuits 137 and 138 may be used. After forming bumps to connect the pads 133 and 134 to the integrated circuits 137 and 138, the pads 133 and 134 and the integrated circuits 137 and 138 are formed using the bumps. There is a COG (Chip On Glass) method of connecting.

In the COG method, the integrated circuits 137 and 138 are directly mounted on the substrate of the liquid crystal display panel 130, and the bump and anisotropic conductive film is not used without using a film used for a tape automated bonding (TAP) method. The integrated circuits 137 and 138 are bonded to the substrate of the liquid crystal display panel 130 only with ACF.

4A is a plan view schematically illustrating a pad unit of a conventional LCD. 4B is a cross-sectional view of the pad part of FIG. 4A taken along the line AA ′. 4C is a cross-sectional view of the pad part of FIG. 4A taken along the line BB ′. 4A to 4C illustrate the gate pad portion of the liquid crystal display panel as an example, but the data pad portion of the liquid crystal display panel may have the same structure.

4A to 4C, the pad part may deposit a conductive film such as chromium (Cr) or aluminum (Al) on an insulating substrate 100 such as glass, and pattern the same to form a gate pad 142. The gate pad 142 may be integrally formed at an end extending from the gate line 141 simultaneously formed on the liquid crystal display panel.

Depositing a gate insulating layer 146 made of silicon nitride on the substrate 100 on which the gate pad 142 is formed, and then forming a protective layer 147 made of an inorganic material or an organic material on the gate insulating layer 146. Thereafter, the gate insulating layer 146 and the protective layer 147 formed on the gate pad 142 are removed by a photolithography process. In this case, a pad contact hole 143 exposing the gate pad 142 is formed.

After depositing a transparent conductive film such as ITO or IZO on the pad contact hole 143 and patterning it by a photolithography process, a metal electrode (or respectively) connected to the gate pad 142 through the pad contact hole 143. ITO or IZO electrode) 145 is formed. In this case, the metal electrode 145 may be formed of the same material as the pixel electrode formed on the liquid crystal display panel and formed at the same time.

The ACF 148 containing the conductive balls 148a is coated on the metal electrode 145 formed on the pad contact hole 143 and bumps connected to the terminals of the integrated circuit (eg, the gate integrated circuit) are disposed thereon. When the 149 is compressed, the conductive ball 148a of the ACF 148 applied between the bump 149 and the metal electrode 145 is compressed to compress the bump 149 and the metal electrode 145. Electrical connection.

Accordingly, the scan voltage generated in the gate integrated circuit is transferred to the metal electrode 145 through the bump 149 and then supplied to the gate pad 142 electrically connected to the metal electrode 145. The scan voltage is supplied to the liquid crystal display panel through the gate line 141 integrally connected to the gate pad 142.

However, in the conventional pad part structure as described above, when the bump 149 is pressurized by thermocompression bonding and connected to the metal electrode 145, galvanic corrosion occurs and aluminum or chromium is formed. The gate pad 142 is corroded and eventually causes disconnection. That is, an electrochemical reaction occurs due to heat applied to the integrated circuit to attach the bump 149, and thus, the gate pad 142 may be corroded as the fine gate pad particles are separated.

Therefore, when the gate pad 142 is disconnected, the signal supplied to the liquid crystal display panel is not transmitted properly, resulting in poor driving characteristics for image display. In extreme cases, it may not be driven at all, and a predetermined image may not be displayed on the screen.

Accordingly, an object of the present invention is to provide a liquid crystal display device and a method of manufacturing the same, which can prevent corrosion occurring in a pad when directly connected to a pad.

According to a preferred embodiment of the present invention for achieving the above object, the liquid crystal display device, the liquid crystal display panel consisting of a liquid crystal injected between the first substrate, the second substrate and the first and second substrate; A pad unit formed in the non-display area when the display area and the non-display area are divided on one of the first and second substrates; And

An integrated circuit mounted on the pad part to be electrically connected to generate a signal for operating the liquid crystal display panel, wherein the pad part includes a first area in which contact holes are not formed and a second area in which contact holes are formed; The bump of the integrated circuit is attached to a first region where the contact hole is not formed.

In this case, a metal electrode is formed over the first region and the second region. Specifically, the metal electrode is formed on the protective layer in the first region, and on the pad exposed by the contact hole in the second region. Can be.

The bump of the integrated circuit may be attached to a metal electrode formed in the first region.

An ACF containing a conductive ball may be applied onto the metal electrode before the bump of the integrated circuit is attached.

The pad part may be applied to the gate pad part and / or the data pad part.

According to another preferred embodiment of the present invention, a method of manufacturing a liquid crystal display includes: forming a plurality of pads on a substrate having a bump attachment region where a contact hole is not formed and a contact hole formation region where a contact hole is formed; Forming a protective layer on the substrate on which the pads are formed; Forming a contact hole for each pad by removing a protective layer corresponding to the contact hole forming region of the protective layer; Forming a metal electrode by applying and patterning a conductive film over the bump attaching region and the contact hole forming region; And attaching a bump of an integrated circuit on a metal electrode formed in the bump attach region.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

5A to 5D are diagrams illustrating a pad part capable of preventing pad corrosion in a liquid crystal display according to an exemplary embodiment of the present invention. Specifically, FIG. 5A is a plan view schematically illustrating a pad part capable of preventing pad corrosion in a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 5B is a diagram illustrating the pad part of FIG. 5A taken along line CC ′. 5C is a cross-sectional view of the pad part of FIG. 5A taken along the line DD ′, and FIG. 5D is a cross-sectional view of the pad part of FIG. 5A taken along the line EE ′.

5A through 5D illustrate the gate pad portion of the liquid crystal display panel as an example, the data pad portion of the liquid crystal display panel may have the same structure.

5A to 5D, the pad portion of the present invention further extends the length of the pad portion in the longitudinal direction as compared with the conventional art, and the pad portion thus extended includes a gate integrated circuit in one region (ie, a bump attachment region). The bump 19 is attached and the pad contact hole 13 is formed in the other region (that is, the contact hole forming region).

In this case, as shown in FIGS. 5B and 5D, the pad contact hole may not be formed in the pad portion corresponding to the bump attachment region. That is, the gate insulating layer 15 and the protective layer 16 are sequentially formed on the substrate 20 on which the gate pad 12 is formed, and the transparent conductive film material such as ITO or IZO is formed on the protective layer 16. The metal electrode 14 made of a pattern is formed. When the ACF 17 containing the conductive balls 17a is applied and then the bumps 19 of the gate integrated circuit are positioned and pressed by thermocompression, the bumps 19 are made of the resin material of the ACFs 17. Through the conductive ball 17a is connected to the metal electrode 14 through.

In contrast, as illustrated in FIGS. 5C and 5D, the pad contact hole 13 is formed in the pad part corresponding to the contact hole forming region. That is, the gate insulating layer 15 and the protective layer 16 are sequentially formed on the substrate 20 on which the gate pad 12 is formed, and the gate insulating layer formed on the gate pad 12 by a photolithography process ( 15) and the protective layer 16 are removed. As the gate insulating layer 15 and the protective layer 16 are removed as described above, a pad contact hole 13 is formed on the gate pad 12.

Metal electrodes connected to the gate pads 12 through the pad contact holes 13 by depositing a transparent conductive film such as ITO or IZO on the pad contact holes 13 formed as described above and patterning them by a photolithography process. (14) is formed. In this case, the metal electrode 14 may be formed of the same material as the pixel electrode formed on the liquid crystal display panel and formed simultaneously.

Here, the metal electrode 14 formed in the contact hole forming region is formed to extend on the protective layer 16 of the bump attach region.

The pad portion of the present invention extends in the longitudinal direction and is divided into a bump attaching region and a contact hole forming region. In this case, the pad part including the bump attaching region and the contact hole forming region is formed on the substrate 20. That is, the gate pad 12 is formed on both the bump attaching region and the contact hole forming region on the substrate 20, and the gate insulating layer 15 and the protective layer 16 are sequentially formed on the gate pad 12. Will be formed. In this case, the gate insulating layer 15 and the protective layer 16 on the contact hole forming region are removed to form the pad contact hole 13.

Then, the metal electrode 14 is formed on the protective layer 16 in the bumping region and the pad contact hole 13 in the contact hole forming region. That is, the metal electrode 14 is formed from the bump attaching region to the contact hole forming region. In this case, as the pad contact hole is not formed, the metal electrode 14 formed on the bump-attached area is spaced apart from the gate pad 12 by the gate insulating layer 15 and the protective layer 16.

Subsequently, the ACF 17 containing the conductive balls 17a is applied onto the metal electrode 14, and then, by pressing the bumps 19 of the integrated circuit by thermocompression on the bump attachment position, the conductive balls ( The bump 19 and the metal electrode 14 are connected to each other via 17a).

Although the present invention describes that the ACF 17 is applied to both the bump attaching region and the contact hole forming region, the ACF 17 may be applied only to the bump attaching region if necessary.

As described above, in the case of the gate pad portion, the gate insulating layer 15 and the protective layer 16 are formed on the gate pad 12, but in the case of the data pad portion, the data pad is formed between the gate insulating layer and the protective layer. Therefore, in order to form the contact hole, only the protective layer needs to be removed, and since such null is already known in the art, further description thereof will be omitted.

Accordingly, a signal (eg, a scan voltage) generated in the integrated circuit is transmitted to the metal electrode 14 of the bump attach region through the bump 19, and the transmitted signal flows along the metal electrode 14. The gate pad 12 is transferred to the gate pad 12 through the pad contact hole 13 formed in the contact hole forming region, and then supplied to the gate line 11 integrally connected to the gate pad 12.

Thus, as the attached bumps 19 formed on the bump attaching region are spaced by the gate insulating layer 15 and the protective layer 16 rather than directly connected to the gate pad 12, the rows of the bumps 19 Galvanic corrosion of the gate pad 12 due to the compression is not generated.

6A to 6F are diagrams for describing a method of manufacturing a pad part capable of preventing pad corrosion according to an exemplary embodiment of the present invention.

First, as shown in FIG. 6A, a conductive film such as chromium (Cr) or aluminum (Al) is deposited on an insulating substrate 20 such as glass and patterned to form a plurality of gate pads 12. Here, each of the gate pads 12 may be integrally formed at an end extending from each of a plurality of gate lines simultaneously formed in the liquid crystal display panel.

As shown in FIG. 6B, a gate insulating layer 15 made of silicon nitride is deposited on the substrate 20 on which the gate pads 12 are formed, and then an inorganic or organic material is formed on the gate insulating layer 15. A protective layer 16 is formed.

As shown in FIG. 6C, a gate insulating layer 15 formed on the gate pads 12 is disposed in a bump attach region, which is an region to which an integrated circuit (eg, a gate integrated circuit) is attached using a photolithography process. Instead of removing the protective layer 16, the gate insulating layer 15 and the protective layer 16 formed on the gate pads 12 located in the contact hole forming region, which is the region where the contact hole 13 is formed. Remove it. Accordingly, the gate insulating layer 15 and the protective layer 16 are removed in the contact hole forming region so that the gate pads 12 are exposed to correspond to the gate insulating layer 15 and the protective layer 16. A plurality of pad contact holes 13 having a step may be formed.

As shown in FIG. 6D, a transparent conductive film such as ITO or IZO is deposited on the protective layer 16 located in the bump attaching region and the pad contact holes 13 located in the contact hole forming region. It is patterned by a photolithography process to form a plurality of metal electrodes 14 connected to each of the gate pads 12 through the pad contact holes 13. In this case, the metal electrodes 14 may be formed of the same material as the pixel electrodes formed on the liquid crystal display panel and formed simultaneously.

By this manufacturing method, a predetermined pad portion is completed. In this case, the pad part may be applied to both the gate pad part and the data pad part of the liquid crystal display panel.

At this time, in order to mount the integrated circuit in such a pad part, as shown in FIG. 6E, conductive balls 17a are included on the metal electrodes 14 over the bump attaching region and the contact hole forming region. Apply ACF 17. The ACF 17 is a member in which a plurality of conductive balls 17a are contained in a resin material.

6F aligns the bumps 19 connected to the terminals of the integrated circuit to the corresponding metal electrodes 14 on the ACF 17 located in the bump attaching area, and then compresses them by applying pressure and heat. When the bumps 19 penetrate the ACF 17 and penetrate into the inside to compress the conductive balls 17a existing therein, the bumps 19 and the metal electrodes corresponding thereto. 14 is to be electrically connected.

Therefore, the contact pads 13 are not formed, so that the gate pads 12 and the metal electrodes 14 corresponding thereto are spaced apart from the bump insulation region 15 by the gate insulating layer 15 and the protective layer 16. The bumps 19 of the integrated circuit are respectively connected to the metal electrodes 14, and the gate insulating layer 15 and the protection are in contact with the gate pads 12 and the corresponding metal electrodes 14, respectively. The pad contact hole 13 is formed in the contact hole forming region from which the layer 16 is removed. Accordingly, the signal generated in the integrated circuit is transmitted to the metal electrodes 14 formed in the bump attaching region through the bumps 19 and flows to the metal electrodes 14 formed in the contact hole forming region to correspond. The gate pads may be transferred to the gate pads 12 and supplied to the gate lines of the liquid crystal display panel respectively connected to the gate pads 12.

As described above, the present invention extends the pad portion of the liquid crystal display device in a predetermined length direction to connect the bump of the integrated circuit to the first region where the contact hole is not formed, and to the gate pad through the second region where the contact hole is formed. By transmitting a predetermined signal, it is possible to prevent pad corrosion generated when the bumps of the integrated circuit are connected to a portion where a contact hole is conventionally formed.

Therefore, by preventing the pad corrosion in advance in advance, it is possible to accurately supply a predetermined signal to the liquid crystal display panel to display a high quality image.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

1 is a view schematically showing a general liquid crystal display panel.

FIG. 2 is a schematic view of a liquid crystal display device having a liquid crystal display panel of FIG.

FIG. 3 illustrates a thin film transistor of the liquid crystal display panel of FIG. 1. FIG.

4A is a plan view schematically illustrating a pad unit of a conventional liquid crystal display device;

4B is a cross-sectional view of the pad portion of FIG. 4A taken along line AA ′.

4C is a cross-sectional view of the pad part taken along the line BB ′ of FIG. 4A;

5A to 5D are diagrams illustrating a pad part capable of preventing pad corrosion in a liquid crystal display according to an exemplary embodiment of the present invention.

6A to 6F are views for explaining a method of manufacturing a pad part capable of preventing pad corrosion according to an exemplary embodiment of the present invention.

<Explanation of symbols for main parts of the drawings>

12 gate pad 13 pad contact hole

14 metal electrode 17 ACF

19: bump

Claims (10)

A liquid crystal display panel comprising a first substrate, a second substrate, and a liquid crystal injected between the first and second substrates; A pad unit formed in the non-display area when the display area and the non-display area are divided on one of the first and second substrates; And An integrated circuit mounted on the pad part to be electrically connected to generate a signal for operating the liquid crystal display panel; The pad part includes a first region in which no contact hole is formed and a second region in which a contact hole is formed, and a bump of the integrated circuit is attached to a first region in which the contact hole is not formed. . The liquid crystal display of claim 1, wherein a metal electrode is formed over the first region and the second region. The liquid crystal display device according to claim 2, wherein the metal electrode is formed on the protective layer in the first region, and on the pad exposed by the contact hole in the second region. The liquid crystal display device of claim 1, wherein the bumps of the integrated circuit are attached to a metal electrode formed in the first area. The liquid crystal display device according to claim 1, wherein an ACF containing a conductive ball is coated on the metal electrode before the bump of the integrated circuit is attached. The liquid crystal display device of claim 1, wherein the metal electrode formed in the first region is spaced apart from the pad by the protective layer. Forming a plurality of pads on a substrate having a bump attachment region in which contact holes are not formed and a contact hole formation region in which contact holes are formed; Forming a protective layer on the substrate on which the pads are formed; Forming a contact hole for each pad by removing a protective layer corresponding to the contact hole forming region of the protective layer; Forming a metal electrode by applying and patterning a conductive film over the bump attaching region and the contact hole forming region; And Attaching a bump of an integrated circuit on a metal electrode formed in the bump attaching region Method of manufacturing a liquid crystal display device comprising a. The method of claim 7, wherein the metal electrode is formed on the passivation layer in the bump attaching region and on the pad exposed by the contact hole in the contact hole forming region. . The method of claim 7, wherein the metal electrode formed in the bump attaching region is spaced apart from the plurality of pads by the protective layer. 8. The method of claim 7, further comprising applying an ACF containing conductive balls onto the metal electrode prior to attaching the bumps of the integrated circuit. Method of manufacturing a liquid crystal display device further comprising.