JPH0933939A - Liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To narrow the frame region of a liquid crystal display device. SOLUTION: This device is the liquid crystal display device arranged with a liquid crystal drive element 3 and a circuit board 4 in the peripheral part of a liquid crystal panel 2, electrically connecting one end of the liquid crystal drive element 3 to the liquid crystal panel 2 and the other end to the circuit board 4. Then, the circuit board 4 is made a multi-layer wiring board, and is constituted so that at least one layer extend to the side of the liquid crystal panel 2, and the extended layer 41 is fixed to the surface opposite to the connection surface between the liquid crystal panel 2 and the liquid crystal drive element 3.

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 device suitable for narrowing a frame.

[0002]

2. Description of the Related Art As shown in FIG. 4, a conventional liquid crystal display device is provided with a reinforcing plate 63 for fixing or reinforcing a circuit board 62 arranged around a liquid crystal panel 61. The liquid crystal panel 61 and the circuit board 62 are fixed to the back surface with an adhesive such as a double-sided tape.

[0003]

Since it is necessary to secure a bonding margin 64 with the reinforcing plate 63 on the circuit board 62, this bonding margin 64 portion becomes a dead space in which no circuit component can be mounted, and the bonding margin 64 of the liquid crystal display device. This is the cause of widening of the panel surrounding area called a frame. Further, generally, the reinforcing plate 63 is made of synthetic resin in consideration of electric insulation, but is easily thermally expanded in the longitudinal direction due to the influence of the surrounding heat. When the expansion of the reinforcing plate 63 exceeds a predetermined value, the circuit board 62 may be curved, and the liquid crystal drive element 65 connected between the liquid crystal panel 61 and the circuit board 62 is unnecessarily affected by the curvature. May be stressed. Therefore, it is an object of the present invention to provide a liquid crystal display device which has high reliability and is easy to assemble, while making it a main object to narrow a frame of the liquid crystal display device.

[0004]

According to the present invention, in a liquid crystal display device in which a circuit board is arranged in the peripheral portion of a liquid crystal panel, the circuit board is constituted by a multilayer wiring board having a layer extending toward the liquid crystal panel. At the same time, the extension layer is fixed to the liquid crystal panel. The extension layer may be the outermost layer of the multilayer wiring board.

The present invention also provides a liquid crystal display device in which a liquid crystal driving element and a circuit board are arranged in the peripheral portion of the liquid crystal panel, and one end of the liquid crystal driving element is electrically connected to the liquid crystal panel and the other end is electrically connected to the circuit board. , The circuit board is a multilayer wiring board, and at least one layer thereof is configured to extend to the liquid crystal panel side, and the extending layer is fixed to a surface of the liquid crystal panel opposite to a connection surface to the liquid crystal drive element. It is characterized by having done.

[0006]

According to the present invention, since the circuit board is constituted by the multilayer wiring board having the layer extending toward the liquid crystal panel side and the extending layer is fixed to the liquid crystal panel, the extending layer has a function as a reinforcing plate. By doing so, it is possible to reduce the adhesive margin of the reinforcing plate set on the circuit board, and to narrow the frame by a length corresponding to the adhesive margin of the reinforcing plate. Further, the number of fixing points between the liquid crystal panel and the circuit board can be reduced, the workability of fixing can be improved, and the reliability after fixing can be maintained well. By making the extension layer the outermost layer of the multilayer wiring board, it becomes easy to arrange the circuit board within the thickness range of the liquid crystal panel.

Further, according to the present invention, the circuit board is a multilayer wiring board and at least one layer thereof is extended to the liquid crystal panel side, and the extension layer is provided on the side opposite to the connection surface of the liquid crystal panel to the liquid crystal drive element. Since the circuit board is fixed to the surface, the circuit board can be fixed to the front and back sides of the liquid crystal panel by the liquid crystal drive element and the extension layer, and can be more reliably fixed to the liquid crystal panel. Since the extension layer is fixed to the surface of the liquid crystal panel opposite to the connection surface with the liquid crystal drive element, the extension layer can be fixed to the liquid crystal panel without being disturbed by the connection between the liquid crystal panel and the liquid crystal drive element. You can

[0008]

Embodiments of the present invention will be described below with reference to the drawings. The liquid crystal display device 1 has a planar rectangular shape as shown in FIG. 3, and a liquid crystal panel 2 and this liquid crystal panel 2 as shown in FIGS. 1 and 2 taken along the lines AA and BB in FIG. The liquid crystal drive element 3 and the circuit board 4 arranged in the peripheral part of the liquid crystal display panel 4 and the frame body 5 for accommodating them are mainly configured, and the surface lighting device 6 is disposed on the back side of the liquid crystal panel 2 if necessary. are doing.

The liquid crystal panel 2 encloses liquid crystal between two transparent substrates 21 and 21 having a plurality of transparent electrodes on opposite surfaces, and a polarizing plate so that the transparent substrates 21 and 21 are sandwiched as necessary. 22 and 22 are arranged and configured. The transparent electrode extends to a terminal portion 23 provided on the edge of the transparent substrate 21 and a part thereof is exposed. The output terminal portion of the liquid crystal drive element 3 is bonded to the exposed transparent electrode by an anisotropic conductive adhesive or the like. It is connected by heating and pressurizing it through the agent. The liquid crystal driving element 3 is called a so-called TCP (tape carrier package) in which a film-shaped base material is provided with a predetermined electric wiring pattern and an IC element 31 for driving the liquid crystal is arranged in the center thereof. The liquid crystal panel 2 includes a plurality of components, and a plurality of components are arranged on one side of the liquid crystal panel 2. The input terminal portion of the liquid crystal drive element 3 is connected to the terminal portion formed on the surface of the circuit board 4 by solder or anisotropic conductive adhesive. The circuit boards 4 are arranged along two to four sides of the liquid crystal panel 2, and are electrically connected to the liquid crystal panel 2 via the plurality of liquid crystal drive elements 3.

The circuit board 4 is composed of, for example, a multilayer wiring board having two or more layers and preferably having a structure of 6 to 8 layers.
Hereinafter, the circuit board 4 is also referred to as a multilayer wiring board 4. Each layer of the multilayer wiring board 4 is formed by wiring an electric circuit with a copper foil or the like on an insulating base material having a predetermined rigidity such as glass epoxy resin, and laminating a plurality of these layers with an insulating layer interposed therebetween. Multilayer wiring board 4 by thermocompression bonding and integration
Is formed. At least one layer of the multilayer wiring board 4, preferably one or more layers including the outermost layer (the layer located on the side opposite to the side where the liquid crystal drive element 3 is connected),
In order to configure the extension layer 41 extending in the direction of the liquid crystal panel 2, the area is set larger than that of the other layers. By doing so, the extension layer 41 extending in the direction of the liquid crystal panel 2 and having a predetermined rigidity can be integrally formed on the circuit board 4. The extension layer 41 has a dimension slightly longer than the length of the terminal portion 23 of the liquid crystal panel 2, and is provided along the longitudinal direction of the circuit board 4. The other circuit boards 4 connected to the peripheral portion of the liquid crystal panel 2 are similarly configured.

The circuit board 4 is used as the liquid crystal panel 2.
Of the double-sided adhesive tape, a thermosetting resin, or an ultraviolet-curing resin is used for the extension layer 41 so as to be within the thickness range of the liquid crystal panel 2 along the rear surface (the liquid crystal driving element 3). It is fixed integrally to the liquid crystal panel 2 by fixing it on the surface opposite to the connecting portion).
1 and 2 on the short side and the long side of the liquid crystal panel 2.
As shown in FIG. 3, the liquid crystal drive element 3 and the circuit board 4 are mounted upside down, but the liquid crystal drive element 3 and the circuit board 4 are fixed to the liquid crystal panel 2 by the same procedure.

Since the extending layer 41 functions as a reinforcing plate, there is no need to provide a reinforcing plate bonding margin as in the conventional circuit board, and a liquid crystal display corresponding to the reinforcing plate bonding margin is provided. The width of the frame portion of the device can be shortened. Furthermore, when the reinforcing plate is used, two places are required to bond and fix the liquid crystal panel 2 and the circuit board 4,
According to this method, the number of parts is as small as one, and the fixing workability,
The reliability after fixing can also be improved. Since the extension layer 41 of the circuit board 4 is fixed to the liquid crystal panel 2,
It is not affected by the thermal expansion of the reinforcing plate as in the case of the conventional fixing by the reinforcing plate, the stress applied to the liquid crystal driving element 3 is reduced, and the reliability of the connecting portion of the liquid crystal driving element 3 is kept good. You can

Further, the extension layer 41 includes the liquid crystal panel 2 and the frame 5 (or the cushioning member 51) supporting the liquid crystal panel 2.
Since it is sandwiched by, it is possible to more reliably prevent the adhesive fixing portion from coming off. In addition, since the extension layer 41 is fixed to the surface of the liquid crystal panel 2 opposite to the connection surface with the liquid crystal drive element 3, that is, the rear surface of the terminal portion 23,
The circuit board 4 can be fixed to the front and back sides of the liquid crystal panel 2 by the liquid crystal drive element 3 and the extension layer 41, and can be more reliably fixed to the liquid crystal panel. Then, since the extension layer 41 is fixed to the surface of the liquid crystal panel 2 opposite to the connection surface with the liquid crystal drive element 3, the extension layer 41 is provided without being disturbed by the connection between the liquid crystal panel 2 and the liquid crystal drive element 3. It can be fixed to the liquid crystal panel 2.

[0014]

According to the present invention, since the circuit board is constituted by the multilayer wiring board having the layer extending toward the liquid crystal panel side and the extending layer is fixed to the liquid crystal panel, the extending layer serves as a reinforcing plate. By having the function of, it is possible to reduce the adhesive margin of the reinforcing plate set on the circuit board and to narrow the frame by a length corresponding to the adhesive margin of the reinforcing plate.
Further, the number of fixing points between the liquid crystal panel and the circuit board can be reduced, the workability of fixing can be improved, and the reliability after fixing can be maintained well. By making the extension layer the outermost layer of the multilayer wiring board, it becomes easy to arrange the circuit board within the thickness range of the liquid crystal panel.

Further, according to the present invention, the circuit board is a multilayer wiring board and at least one layer thereof is extended to the liquid crystal panel side, and the extended layer is provided on the side opposite to the connection surface of the liquid crystal panel to the liquid crystal drive element. Since the circuit board is fixed to the surface, the circuit board can be fixed to the front and back sides of the liquid crystal panel by the liquid crystal drive element and the extension layer, and can be more reliably fixed to the liquid crystal panel. Since the extension layer is fixed to the surface of the liquid crystal panel opposite to the connection surface with the liquid crystal drive element, the extension layer can be fixed to the liquid crystal panel without being disturbed by the connection between the liquid crystal panel and the liquid crystal drive element. You can

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a main part (AA in FIG. 3) of a liquid crystal display device showing an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part (BB in FIG. 3) of a liquid crystal display device showing an embodiment of the present invention.

FIG. 3 is a plan view of a liquid crystal display device showing an embodiment of the present invention.

FIG. 4 is an enlarged cross-sectional view of a main part (a portion corresponding to AA in FIG. 3) of a conventional liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal display device 2 Liquid crystal panel 3 Liquid crystal drive element 4 Circuit board 41 Extension layer

Claims (3)

[Claims] 1. In a liquid crystal display device in which a circuit board is arranged in the peripheral portion of a liquid crystal panel, the circuit board is constituted by a multilayer wiring board having a layer extending toward the liquid crystal panel, and the extending layer is formed by the above-mentioned extension layer. A liquid crystal display device characterized by being fixed to a liquid crystal panel. 2. A liquid crystal display device in which a circuit board is arranged in a peripheral portion of a liquid crystal panel, wherein the circuit board is a multilayer wiring board and an outermost layer thereof is extended to the liquid crystal panel side, and the extended layer is provided. Is fixed to the liquid crystal panel. 3. A liquid crystal driving element and a circuit board are arranged in the peripheral portion of the liquid crystal panel, and one end of the liquid crystal driving element is placed on the liquid crystal panel.
In a liquid crystal display device in which the other end is electrically connected to a circuit board, the circuit board is a multilayer wiring board, and at least one layer thereof is extended toward the liquid crystal panel side, and the extended layer is formed in the liquid crystal panel. A liquid crystal display device, characterized in that the liquid crystal display device is fixed to a surface opposite to the connection surface to the liquid crystal driving element.