JPH11174483A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal display device capable of maintaining an excellent image without being damaged on connection parts between parts, etc., even when a the environmental temperature changes or the liquid-crystal display panel is warped. SOLUTION: A printed-wiring board 20 is arranged along a long side of a rectangular liquid-crystal display panel 12, and this printed-wiring board 20 is connected with the liquid-crystal display panel via plural TCPs 28 (tape carrier package). The printed-wiring board 20 is divided into two at the center part in the direction of its long side, and these divided parts 20a, 20b are connected with each other via a flexible wiring board 24.

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, and more particularly, to a liquid crystal display having a printed wiring board connected to a liquid crystal display panel via a tape carrier package.

[0002]

2. Description of the Related Art A liquid crystal display device has a rectangular liquid crystal display panel. This liquid crystal display panel is an array substrate provided with a large number of signal lines and scanning lines, pixel electrodes, switching elements and the like formed in a matrix. And a counter substrate disposed to face the array substrate, and liquid crystal molecules sealed between the array substrate and the counter substrate.

Generally, the following method is used to supply signals to a liquid crystal display panel. That is, various power supplies and signals supplied from a signal source, for example, a personal computer main body, are collectively received by the input connector section, signal processing is performed on the control board, and the signals are transmitted to any side of the liquid crystal display panel. It is supplied to a liquid crystal display panel via a tape carrier package (hereinafter, referred to as TCP) on which a driving semiconductor element is mounted by a printed wiring board provided along. Since the liquid crystal display device performs image display by a scanning method, a scanning signal and an image data signal are supplied to the liquid crystal display panel.

A display device for a personal computer or a television generally uses a horizontally long rectangular screen. Therefore, a method has been adopted in which a scanning signal is supplied from the short side of the liquid crystal panel and an image data signal is supplied from the long side. For this reason, the liquid crystal display device has four sides around the liquid crystal display panel,
At least one printed wiring board is arranged on each of the long side and the short side, and each printed wiring board is connected to a liquid crystal display panel via a plurality of TCPs.

[0005]

In the liquid crystal display device having the above structure, the liquid crystal display panel mainly made of glass and the printed wiring board made of an insulating material such as epoxy have different coefficients of thermal expansion, and when the environmental temperature changes. , A difference occurs in the amount of elongation. In particular, in a liquid crystal display device having a large-sized liquid crystal display panel, the length of a printed wiring board provided along the liquid crystal display panel becomes long, and the difference in the amount of elongation when a temperature change occurs also becomes large. Such a difference in the amount of elongation causes a relative displacement between the liquid crystal display panel and the printed wiring board, and the amount of the displacement becomes maximum at both ends in the longitudinal direction of the printed wiring board.

Similarly, when a shock is applied to the liquid crystal display device and the entire device is warped such that the long side of the liquid crystal display panel is curved, the relative position between the liquid crystal display panel and the printed wiring board is similarly increased. Misalignment occurs. When the dimensions of the liquid crystal display panel and the printed wiring board are large, the amount of displacement also increases.

[0007] When a relative displacement occurs between the liquid crystal display panel and the printed wiring board due to thermal expansion or warpage, stress acts on the TCP connecting them, and a structurally weak portion is formed. Will be destroyed. For example,
The wiring pattern of the TCP is disconnected, the resin potting portion of the semiconductor chip is broken, or the soldering portion between the TCP and the printed wiring board is disconnected. As a result, defects occur on the screen of the liquid crystal display panel, and it is difficult to display a good image.

The present invention has been made in view of the above points, and has as its object to prevent damage to a connection portion between components even when an environmental temperature changes or a liquid crystal display panel is warped. It is an object of the present invention to provide a liquid crystal display device capable of maintaining a good image.

[0009]

In order to achieve the above object, a liquid crystal display device according to the present invention comprises a rectangular liquid crystal display panel and printed wiring arranged along at least one side of the liquid crystal display panel. And a plurality of tape carrier packages connecting the one side of the liquid crystal display panel and the printed wiring board, wherein the printed wiring board comprises:
It is characterized by being divided into a plurality of pieces along the longitudinal direction of the one side.

Further, the liquid crystal display device according to the present invention has a rectangular liquid crystal display panel, a printed wiring board disposed along one long side of the liquid crystal display panel, and the long side of the liquid crystal display panel. And a plurality of tape carrier packages connected to the printed wiring board, wherein the printed wiring board is divided into two at a longitudinal central portion of the long side, and the two divided printed wiring boards are divided. The plate portions are characterized by being connected to each other via a flexible wiring board.

As described above, when the printed wiring board is divided into a plurality of parts, the amount of thermal expansion of each divided portion is smaller in inverse proportion to the number of divisions than that of a single undivided printed wiring board. Become. Therefore, even when the environmental temperature changes and the liquid crystal display panel and the printed wiring board thermally expand,
The difference in the amount of thermal expansion between the liquid crystal display panel and each divided portion of the printed wiring board can be reduced, and the relative displacement can be reduced. As a result, it is possible to reduce the stress generated in the tape carrier package, and to prevent damage to the connection portion, disconnection, and the like.

Similarly, when the liquid crystal display device is subjected to a shock and the liquid crystal display panel and the printed wiring board are warped, the relative displacement between the liquid crystal display panel and the printed wiring board is reduced, and the connecting portion generated in the tape carrier package is similarly reduced. Damage, disconnection, and the like can be prevented.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a liquid crystal display according to an embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the liquid crystal display device 10 is configured as a normally white mode light transmission type liquid crystal display device, and has a rectangular liquid crystal display panel 12, a driving unit 14 for driving the liquid crystal display panel, It has.

The liquid crystal display panel 12 includes a rectangular array substrate 16 and a counter substrate 18, and these substrates are opposed to each other with a predetermined gap by bonding their peripheral edges with a sealing agent (not shown). . Liquid crystal molecules (not shown) are sealed between the array substrate 16 and the opposing substrate 18.

The array substrate 16 is formed by forming a large number of signal lines and scanning lines in a matrix on a rectangular glass plate and forming a large number of pixel electrodes, switching elements, and the like. Note that the scanning lines extend along a direction parallel to the long side of the array substrate 16, and the signal lines extend along a direction parallel to the short side of the array substrate.

The opposing substrate 18 is formed by forming opposing electrodes on a glass substrate slightly smaller in size than the array substrate 16. On the other hand, the drive unit 14 includes an elongated first printed wiring board 20 for driving signal lines, which is disposed along one long side of the array substrate 16, and one short side of the array substrate. And a second elongated printed rectangular wiring board 22 for driving scanning lines.

The first printed wiring board 20 is formed of an insulating material such as epoxy, extends over substantially the entire length of the long side of the array substrate 16, and is provided on substantially the same plane as the array substrate 16. The first printed wiring board 20 is divided into a first portion 20a and a second portion 20b at the center in the longitudinal direction.

First part 20 as printed wiring board part
a and the second portion 20b are arranged with a predetermined gap therebetween, and are electrically connected to each other via the flexible wiring board 24. The flexible wiring board 24 is provided so as to be slightly slackened in the longitudinal direction of the printed wiring board 20.

The first portion 20a is connected to the array substrate 16 via a plurality of (for example, four) TCPs 28 on each of which a driving semiconductor element 26 is mounted. Similarly, the second
The portion 20b is also connected to the array substrate 16 via the four TCPs 28.
It is connected to the. These TCPs 28 are arranged at predetermined intervals along the long side direction of the array substrate 16 and are each electrically connected to a signal line.

The second printed wiring board 22 is formed of an insulating material such as epoxy, extends over almost the entire short side of the array substrate 16, and is provided on substantially the same plane as the array substrate 16. The second printed wiring board 22 is provided on the array substrate 1 via a plurality of (for example, three) TCPs 32 on which the driving semiconductor elements 30 are mounted.
6 is connected. These TCPs 32 are arranged at predetermined intervals along the short side direction of the array substrate 16 and are also electrically connected to the scanning lines.

According to the liquid crystal display device configured as described above, the first printed wiring board 20 disposed along the long side of the array substrate 16 has the first and second portions 20a and 20a.
b, the first and second portions 20a and 20b are separated from the undivided single printed wiring board even when the liquid crystal display device thermally expands due to a temperature rise. The amount of thermal expansion is about 1/2.

That is, as shown in FIG. 2A, when the first printed wiring board 20 of the conventional single structure thermally expands, the amount of displacement of both ends of the first printed wiring board with respect to the array substrate 16 is represented by a. In this case, the first and second portions 20a and 20b of the first printed wiring board 20 according to the present embodiment
2B is a / 2 as shown in FIG. 2B. Therefore, according to the present embodiment,
The stress acting on each TCP 28 is also reduced to half of the conventional one.

Therefore, even if the environmental temperature changes, T
Preventing the wiring pattern of the CP 28 from being broken, the resin potting portion of the semiconductor chip from being broken, and the soldering portion between the TCP and the printed wiring board from being broken;
Good image display can be performed.

FIGS. 3 and 4 show a liquid crystal display device according to a second embodiment of the present invention. According to the second embodiment, the first printed wiring board 20 is provided along one long side of the liquid crystal display panel 12, and
The liquid crystal display panel 12 is located substantially parallel to and opposed to the rear surface side. Each TCP 28 connecting the first printed wiring board 20 and the array substrate 16 is bent substantially in a U-shape.

Similarly, the second printed wiring board 22 is provided along one short side of the liquid crystal display panel 12 and is located substantially parallel to the back surface of the liquid crystal display panel 12. Each TCP 32 connecting the second printed wiring board 22 and the array substrate 16 is bent in a substantially U-shape.

The first printed wiring board 20 is divided into first and second portions 20a and 20b at the center in the longitudinal direction, and the first and second portions 20a and 20b are divided into two.
b are arranged with a predetermined gap therebetween and are electrically connected to each other via a flexible wiring board 24.

The other structure is the same as that of the above-described first embodiment, and the same parts are denoted by the same reference numerals and detailed description thereof will be omitted. According to the liquid crystal display device 10 configured as described above, the first printed wiring board 20 disposed along the long side of the array substrate 16 is divided into the first and second portions 20a and 20b. Therefore, even when the liquid crystal display device 10 receives an impact and warps in the direction in which the long side of the liquid crystal display panel 12 bends, the amount of displacement of the first and second portions 20a and 20b with respect to the array substrate 16 is It is about 1/2 compared to a single undivided printed wiring board.

That is, as shown in FIG. 5 (a), when the first printed wiring board 20 of the conventional single structure is warped, the amount of displacement of both ends of the first printed wiring board with respect to the array substrate 16 is denoted by b. In this case, the first
First and second portions 20a, 20 of printed wiring board 20
The amount of displacement of each end of b is b / 2, as shown in FIG. Therefore, according to the present embodiment,
The stress acting on each TCP 28 is also reduced to half of the conventional one.

Therefore, even when the liquid crystal display device 10 is warped due to an impact, the wiring pattern of the TCP 28 is broken, the resin potting portion of the semiconductor chip is broken, or the soldering portion between the TCP and the printed wiring board is damaged. Disconnection can be prevented, and good image display can be performed.

Similarly, even when the liquid crystal display device 10 thermally expands due to a change in the environmental temperature, the amount of displacement between the ends of the first and second portions 20a and 20b of the first printed wiring board can be calculated.
It can be reduced to about １ ／ of the conventional printed wiring board, and the stress acting on each TCP 28 can be reduced.
Therefore, the same function and effect as those of the first embodiment can be obtained.

The present invention is not limited to the above-described embodiment, but can be variously modified within the scope of the present invention. For example, the number of divisions of the printed wiring board is not limited to two, and may be increased as necessary. The amount of displacement of the printed wiring board due to thermal expansion or warpage decreases as the number of divisions increases, and the stress acting on each TCP can be further reduced.

In the above-described embodiment, only the printed wiring board provided on the long side of the liquid crystal display panel is divided, but the printed wiring board provided on the short side is also divided. It is good also as a structure which performs.

[0033]

As described above in detail, according to the present invention, since the printed wiring board provided along at least one side of the liquid crystal display panel is divided into a plurality of parts, the environmental temperature is changed. Even in a case where the liquid crystal display panel is warped, it is possible to provide a liquid crystal display device capable of maintaining a good image without being damaged at a connection portion between components and the like.

[Brief description of the drawings]

FIG. 1 is a perspective view of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a shift amount of a printed wiring board with respect to a liquid crystal display panel when the liquid crystal display device thermally expands, in comparison with a conventional liquid crystal display device.

FIG. 3 is a perspective view of a liquid crystal display device according to a second embodiment of the present invention.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a diagram showing a shift amount of a printed wiring board with respect to a liquid crystal display panel when a liquid crystal display device according to a second embodiment warps due to an impact, as compared with a conventional liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Liquid crystal display device 12 ... Liquid crystal display panel 14 ... Drive part 16 ... Array board 18 ... Counter substrate 20 ... 1st printed wiring board 20a ... 1st part 20b ... 2nd part 22 ... 2nd printed wiring board 24 ... Flexible wiring Plates 26, 30 ... Driving semiconductor elements 28, 32 ... TCP

Claims (4)

[Claims] 1. A liquid crystal display panel having a rectangular shape, a printed wiring board disposed along at least one side of the liquid crystal display panel, and a plurality of liquid crystal display panels connected to the one side of the liquid crystal display panel and the printed wiring board. A liquid crystal display device, comprising: a tape carrier package according to claim 1, wherein the printed wiring board is divided into a plurality of pieces along a longitudinal direction of the one side. 2. A liquid crystal display panel having a rectangular shape, a printed wiring board disposed along one long side of the liquid crystal display panel, and the long side of the liquid crystal display panel connected to the printed wiring board. A plurality of tape carrier packages, wherein the printed wiring board is provided at a central portion of the long side in the longitudinal direction.
The liquid crystal display device is divided into two, and the two divided printed wiring board portions are connected to each other via a flexible wiring board. 3. The liquid crystal display device according to claim 1, wherein the printed wiring board is provided on substantially the same plane as the liquid crystal display panel. 4. The liquid crystal display device according to claim 1, wherein the printed wiring board is provided so as to be substantially parallel to the liquid crystal display device, and each of the tape carrier packages is bent in a substantially U-shape. 3. A liquid crystal display device according to 2.