JPH1031423A - Liquid crystal display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the wiring resistance of electrode wirings and to solve such problem that the liquid crystal is not driven by a prescribed voltage due to a voltage drop, by forming metallic films on transparent electrodes and constituting first and second leader electrodes. SOLUTION: A first leader electrode 4, which constitutes of an ITO film, is connected to the driving electrode of a first transparent substrate 1. A first connecting terminal 4A which is to make a contact to a semiconductor chip 3 is located along the extended direction of the electrode 4. A second leader electrode 5A electrically connects second and third connecting terminals 5D and 6. In the electrode wiring and the terminals, the electrode 5A has the two layer construction in which a Ni film is formed by plating on the ITO film. An opening section is provided on the Ni film and ITO films 5C and 6B are exposed in one region at the opening. In other words, the electrode 5A has the two layer construction with the ITO and Ni film. Moreover, the contacting regions of the terminals 5D and 6 are not covered by the Ni film and the ITO film is exposed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display panel, and more specifically, to a COG (Chip On Glass) type in which a semiconductor chip for driving a liquid crystal is directly mounted on a transparent substrate constituting the liquid crystal display panel. Related to improvement of liquid crystal display panels.

[0002]

2. Description of the Related Art A conventional liquid crystal display panel will be described below with reference to the drawings. This is a so-called face-down type COG (Chip On Glass)
It is constructed by directly mounting a semiconductor chip for driving liquid crystal on a transparent substrate constituting a liquid crystal display panel. FIG. 4 is a top view of the device, and FIG. 5 is a sectional view taken along line XX of FIG.

[0005] As shown in FIG.
It has first and second transparent substrates (11, 12) each having a transparent electrode and an alignment film (not shown) formed on the upper surface thereof, and these first and second transparent substrates (11, 12) are arranged to face each other. And the two are fixed with a sealing material (18), and the liquid crystal (1) is interposed between them.
7) is enclosed. As shown in FIG. 4, the end of the first transparent substrate (11) protrudes from the end of the second transparent substrate (12) in an eaves-like manner. 13) is mounted, and predetermined electrode wiring such as a terminal (16) for making contact with an external device is formed.

The eave-shaped portion has an ACF (anisotropic)
(conductivity film: anisotropic conductive film) (19). When mounting the semiconductor chip, align the semiconductor chip at a predetermined position, align the electrode on the semiconductor chip side with the electrode on the panel side, and fix the semiconductor chip by thermocompression bonding from above. Make contact with each other.

FIG. 6 is an enlarged view of the above-mentioned eave-shaped portion before the chip is mounted. In FIG. 6, reference numeral 14 denotes a first lead transparent electrode made of an ITO film, which is connected to a drive electrode (not shown) of the first transparent substrate (11), and 14A extends on the extension of the first lead transparent electrode (14). A first connection terminal for making contact with the semiconductor chip (13), a second connection terminal 15A connected to the semiconductor chip (13), and a connection 16 to an external interface (not shown) connected to the outside; A third connection terminal 15 for electrically connecting the second connection terminal (15A) and the third connection terminal (16) is a second lead transparent electrode made of an ITO film. 13A is an area for mounting the semiconductor chip (13). Also, the first, second and third connection terminals (1
4A, 15A, 16) are all made of ITO films.

As shown in FIG. 5, an anisotropic conductive film (19) is selectively formed on the eave-shaped portion. To mount the semiconductor chip (13), the semiconductor chip (13) is positioned at a predetermined position on the anisotropic conductive film (19), and thermocompression-bonded. Then, the semiconductor chip (13) is fixed on the anisotropic conductive film (19), and a contact between a bump electrode (not shown) of the semiconductor chip and the transparent electrode can be made.

According to the above liquid crystal display panel, the semiconductor chip (13) integrally formed on the first transparent substrate (11) applies a predetermined electric field to the transparent electrode (not shown), and A predetermined image is displayed by driving the liquid crystal molecules of the layer (17) and blocking / transmitting the reflected light.

[0008]

As described above,
The wiring in the above-mentioned eaves-shaped portion was all performed by electrode wiring formed of a single-layer ITO film. However,
The wiring resistance of the ITO film is considerably higher than the wiring resistance of metal wiring and the like. Also, the eaves-shaped portion has a small area, and if a large number of wirings to be connected to the semiconductor chip are formed here, it is necessary to make the wiring thinner, the wiring resistance further increases, a voltage drop occurs, and in severe cases, a predetermined However, there has been a problem that it is not possible to drive with this voltage.

In order to solve this problem, it is conceivable to increase the wiring width of the ITO film. However, the area of the above-mentioned eave-shaped portion is small, and a large number of ITO wirings are routed there. Therefore, if the wiring width is widened, it is difficult to route the wiring, and there is a large limitation in designing the wiring, which makes the design difficult.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional disadvantages. As shown in FIG. 1, a first transparent substrate having a transparent electrode for driving liquid crystal formed on a first transparent substrate is provided. Two transparent substrates, and the first transparent substrate is disposed so as to face the end of the second transparent substrate so as to protrude like an eaves,
Liquid crystal is sealed between the first and second transparent substrates, and is connected to the transparent electrode for driving the liquid crystal on the first transparent substrate projecting like an eaves from an end of the second transparent substrate. A first extraction electrode, a first connection terminal on an extension of the first extraction electrode and connected to a semiconductor chip for driving liquid crystal, a second connection terminal connected to the semiconductor chip, and an external device. A third connection terminal connected to the second connection terminal; and a second extraction electrode connecting the second connection terminal and the third connection terminal, wherein the first and second extraction electrodes are transparent electrodes. A metal film is formed on the transparent electrode, a part of the first, second and third connection terminals is formed by forming the metal film on the transparent electrode, and the remainder is the transparent film. The object is achieved by a liquid crystal display panel comprising only electrodes.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a liquid crystal display panel according to an embodiment of the present invention will be described with reference to the drawings. This is a so-called face-down type COG (Chip On Glas
s), wherein a semiconductor chip for driving a liquid crystal is directly mounted on a transparent substrate constituting a liquid crystal display panel. FIG. 1 is a top view of this device,
FIG. 2 is a sectional view taken along line AA of FIG.

This liquid crystal display panel is, as shown in FIG.
It has first and second transparent substrates (1, 2) each having a transparent electrode and an alignment film (not shown) formed on the upper surface thereof.
The second transparent substrates (1, 2) are arranged to face each other, and both are fixed with a sealant (8), and a liquid crystal (7) is sealed between them. As shown in FIG. 1, the end of the first transparent substrate (1) protrudes in an eaves form from the end of the second transparent substrate (2). 3) is mounted, and predetermined electrode wiring such as a terminal (6) for making contact with an external device is formed.

The eave-shaped portion has an ACF (anisotropic)
(conductivity film: anisotropic conductive film) (19). When mounting the semiconductor chip, align the semiconductor chip at a predetermined position, align the electrode on the semiconductor chip side with the electrode on the panel side, and fix the semiconductor chip by thermocompression bonding from above. Make contact with each other.

FIG. 3 is an enlarged view of the eave-shaped portion before the semiconductor chip is mounted. In FIG. 3, 3A is an area for mounting the semiconductor chip (3). 4 is ITO
A first extraction electrode made of a film, which is connected to a drive electrode (not shown) of the first transparent substrate (1). Reference numeral 4A denotes a first connection terminal for making contact with the semiconductor chip (3), which is on an extension of the first extraction electrode (4).

Reference numeral 5D denotes a second connection terminal connected to the semiconductor chip (3), and reference numeral 6 denotes a second connection terminal for connecting to an externally connected interface (an example of an external device of the present invention). 3 is a connection terminal. 5A is a second extraction electrode, which electrically connects the second connection terminal (5D) and the third connection terminal (6). In the above electrode wiring and terminal, the second extraction electrode (5A) has a two-layer structure in which a Ni film is formed by plating on an ITO film.

Similarly, as shown in FIG. 2, the third connection terminal (6) is formed by forming a Ni film (6B) on the ITO film (6A).
Is formed, and the second connection terminal (5D) is formed by forming a Ni film (5B) on the ITO film (5C). However, these have openings in the Ni film as shown in FIG. 3, and the ITO films (5C, 6B) are exposed in a partial region thereof. These points are characteristic parts of the present invention.

That is, according to the liquid crystal display panel of the present embodiment, since the above-described second extraction electrode (5A) has a two-layer structure of the ITO film and the Ni film, the single-layer ITO film is formed. Compared to the conventional case where only the same wiring was formed,
There is little increase in wiring resistance. Therefore, it is possible to minimize the occurrence of a voltage drop due to an increase in wiring resistance and, as a result, the conventional problem that the liquid crystal display device cannot be driven at a predetermined voltage.

Moreover, since it is not necessary to increase the wiring width in order to prevent an increase in wiring resistance, it is said that widening the wiring width greatly restricts the wiring design and makes the design difficult. Problems can be suppressed. Further, in the present embodiment, the second connection terminal (5
D), in the third connection terminal (6), the ITO film is exposed in the region to be contacted without applying the Ni film. For this reason, it becomes easy when a semiconductor chip or the like is connected thereon to make contact.

By mounting the semiconductor chip on the eave-shaped portion of the first transparent substrate (1) as shown in FIG. 3, the liquid crystal display device as shown in FIG. 1 is completed. An anisotropic conductive film (9) is formed on the eaves-shaped portion. When the semiconductor chip (3) is aligned and thermocompression-bonded, it is fixed on the anisotropic conductive film (9) by thermocompression. In addition, contact between a bump electrode (not shown) of the semiconductor chip and the transparent electrode is established, and a liquid crystal display device is completed.

According to the above liquid crystal display panel, the semiconductor chip (3) integrally formed on the first transparent substrate (1) applies a predetermined electric field to the transparent electrode (not shown),
By driving the liquid crystal molecules of the liquid crystal layer (7) and blocking / transmitting the reflected light, a predetermined image is displayed. In addition,
In this embodiment, the metal film formed on the ITO film is Ni
However, the present invention is not limited to this, and any metal film having a low resistivity (for example, gold) has the same effect.

[0021]

As described above, according to the liquid crystal display panel of the present invention, the first transparent substrate has
A first extraction electrode, a first connection terminal, a second connection terminal, a third connection terminal, and a second extraction electrode are provided;
Since the first and second extraction electrodes are formed by forming a metal film on the transparent electrode, the wiring resistance of the electrode wiring is reduced, and a voltage drop occurs so that the liquid crystal cannot be driven at a predetermined voltage. Deterrence becomes possible.

The first, second and third connection terminals are:
A metal film is formed on the transparent electrode in a part of the region, and the rest of the region is formed only of the transparent electrode. Are exposed, and the contact property here is improved.

[Brief description of the drawings]

FIG. 1 is a top view illustrating a liquid crystal display panel according to an embodiment of the present invention.

FIG. 2 is a sectional view illustrating a liquid crystal display panel according to an embodiment of the present invention.

FIG. 3 is a top view illustrating a main part of the liquid crystal display panel according to the embodiment of the present invention.

FIG. 4 is a top view illustrating a liquid crystal display panel according to a conventional example.

FIG. 5 is a cross-sectional view illustrating a liquid crystal display panel according to a conventional example.

FIG. 6 is a top view illustrating a main part of a liquid crystal display panel according to a conventional example.

[Explanation of symbols]

 (1) First transparent substrate (2) Second transparent substrate (3) Semiconductor chip (4) First extraction electrode (4A) First connection terminal (5A) Second extraction electrode (5B) Ni film (5C) ITO film (5D) Second connection terminal (6) Third connection terminal (6A) Ni film (6B) ITO film (7) Liquid crystal (8) Seal material (9) Anisotropic conductive film

Claims (2)

[Claims] A first transparent substrate having a transparent electrode for driving a liquid crystal formed on a surface thereof; and a second transparent substrate, wherein the first transparent substrate has a first transparent substrate and a second transparent substrate.
Is disposed so as to protrude from an end of the second transparent substrate in an eaves-like manner, a liquid crystal is sealed between the first and second transparent substrates, and an end of the second transparent substrate is provided. A first extraction electrode connected to the transparent electrode for driving the liquid crystal on a first transparent substrate protruding in an eaves-like shape from a portion; and a semiconductor chip for driving the liquid crystal, which is on an extension of the first extraction electrode. A first connection terminal connected to the semiconductor chip, a second connection terminal connected to the semiconductor chip, a third connection terminal connected to an external device, and the second connection terminal and the third connection terminal. A second extraction electrode to be connected; the first and second extraction electrodes are formed by forming a metal film on a transparent electrode; and the first, second and third connection terminals are: A part of the region is formed with the metal film on the transparent electrode, and the rest is formed of the transparent electrode. A liquid crystal display panel, comprising: 2. The liquid crystal display panel according to claim 1, wherein said transparent electrode is made of an ITO film, and said metal film is made of nickel formed by plating.