JP2002341369A - Liquid crystal display device, method of manufacturing the same, and electrode wiring board - Google Patents

Abstract

(57) [Problem] To effectively connect a liquid crystal panel and a film-like wiring body, and to simplify and automate a manufacturing process. SOLUTION: A liquid crystal panel 1 having a liquid crystal layer 14 provided between a pair of a first transparent substrate 11a and a second transparent substrate 11b.
And a circuit board 2 on which a driving element for driving the liquid crystal panel 1 is provided, and a film-shaped wiring body 3 for connecting the liquid crystal panel 1 and the circuit board 2. Is connected to the one side edge of the film-shaped wiring body 3 by the anisotropic conductive film 5, and between the electrode terminal part 17 and the film-shaped wiring body 3. An adhesive layer 7 for adhering them is provided.

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 for connecting a liquid crystal panel and a driving circuit of the liquid crystal panel by a film wiring body, a method of manufacturing the same, and an electrode wiring substrate.

[0002]

2. Description of the Related Art A liquid crystal display device comprises a liquid crystal panel, a circuit board on which a driving element for driving the liquid crystal panel is mounted, a film-like wiring body for electrically connecting the liquid crystal panel and the circuit board, and the like. Anisotropic conductive films that generate conductivity only in the thickness direction are generally used for connecting a liquid crystal panel, a circuit board or the like on which a driving element for driving the liquid crystal panel is mounted, and a film-shaped wiring body.

FIG. 3 is a schematic sectional view showing the structure of a main part of a conventional liquid crystal display device. As shown in FIG. 3, the liquid crystal display device includes a liquid crystal panel 1, a circuit board 2 on which a driving element for driving the liquid crystal panel 1 is mounted, and a TAB (Tape) for electrically connecting the liquid crystal panel 1 and the circuit board 2. Au
tomed Bonding) or FPC (Fl
and a film-shaped wiring body 3 made of an exible printed circuit or the like.

The liquid crystal panel 1 has a first transparent substrate 11a and a second transparent substrate 11b arranged so as to face each other in parallel, and the second transparent substrate 11b has a film-like wiring body 3 on one side edge. An electrode terminal portion 17 for connecting the same is formed so as to extend outward from an end of the first transparent substrate 11a. A counter electrode 12b made of an ITO (indium tin oxide) film or the like is formed on the entire surface of the second transparent substrate 11b. In the liquid crystal panel 1 shown in FIG.
Other picture element electrodes, alignment films, liquid crystal layers, etc. are omitted.

An electrode terminal portion 17 formed on a side edge of one side of the second transparent substrate 11b of the liquid crystal panel 1 is connected to a film-like wiring body via the anisotropic conductive film 5 on the counter electrode 12b. 3 are connected to one side edge. On the surface of the film-like wiring body 3, a foil-like lead wire 31 is formed.
The foil lead 31 and the counter electrode 12b are electrically connected by the anisotropic conductive film 5.

A circuit on which a driving element for driving the liquid crystal panel 1 is mounted via a soldering portion 6 at the other end of the film-shaped wiring body 3 having a foil-shaped lead wire 31 formed on the surface. One end of the substrate 2 is connected. A circuit pattern 21 is formed on the circuit board 2,
The circuit pattern 21 and the foil-shaped lead 31 are electrically connected by the soldering portion 6.

Foil-shaped lead wire 31 on film-shaped wiring body 3
The anisotropic conductive film 5 for electrically connecting the counter electrode 12b of the liquid crystal panel 1 to the liquid crystal panel 1 is formed by mixing fine conductive metal particles in a binder such as a thermoplastic resin or a thermosetting resin. It is formed by molding. The anisotropic conductive film 5 is applied with a heat pressure in the thickness direction at the connection portion, so that conductivity is generated only in the thickness direction by the conductive metal particles, and the anisotropic conductive film 5 is bonded with a binder such as a thermoplastic resin or a thermosetting resin. The nature is also obtained. Therefore, the anisotropic conductive film 5 is required to have, in addition to the above-described conductivity, an adhesive force such that the anisotropic conductive film 5 at the connection portion is not peeled off even when an external stress is generated at the connection portion. Is done.

[0008]

With such a liquid crystal display device, there is an increasing demand for larger images.
Components such as the liquid crystal panel 1, the film-like wiring body 3, and the circuit board 2 also tend to be large. As a result, the external stress generated at the connection between the liquid crystal panel 1 and the film-shaped wiring body 3 is inevitably increased, and the anisotropic conductive film 5 at the connection may be peeled off when a large external stress is applied.

For this reason, as shown in FIG. 4, the side surface of the electrode terminal portion 17 of the liquid crystal panel 1 extends to the intermediate portion of the film-like wiring body 3, and the side surface of the electrode terminal portion 17 and the film-like wiring body 3 are bonded with a reinforcing resin 4 such as a silicone resin to form an electrode terminal portion 17 and a film-shaped wiring body 3.
And a method of reinforcing the adhesive strength between them.

However, in such a method, apart from the step of applying a thermal pressure in the thickness direction at the connecting portion between the electrode terminal portion 17 and the film-shaped wiring body 3, the anisotropic conductive film 5 is not covered with the reinforcing resin 4. Since a coating process is required, simplification and automation of the process are not easy. Further, after the product is completed as a liquid crystal display device, the electrode terminals 1 of the liquid crystal panel 1 are formed.
When a connection failure occurs between the film 7 and the film-shaped wiring body 3, repair thereof is not easy.

As another method for preventing peeling of the anisotropic conductive film 5 at a connection portion between the electrode terminal portion 17 of the liquid crystal panel 1 and the film-shaped wiring body 3, the width of the anisotropic conductive film 5 There is also a method of increasing the bonding area by increasing the dimension in the direction, but in this case, the amount of the anisotropic conductive film 5 used may increase and the material cost may increase.

The present invention has been made to solve such problems, and an object of the present invention is to make it possible to effectively connect a liquid crystal panel and a film-shaped wiring body, and to simplify and automate the manufacturing process. It is another object of the present invention to provide a liquid crystal display device, a method of manufacturing the same, and an electrode wiring substrate which are inexpensive and easy to repair after product completion.

[0013]

A liquid crystal display device according to the present invention comprises: a liquid crystal panel having a liquid crystal layer provided between a pair of transparent substrates; a circuit board having a driving element for driving the liquid crystal panel; An electrode terminal portion provided on at least one side edge of the liquid crystal panel and a film-shaped wiring body for connecting the liquid crystal panel and the circuit board, and one side edge of the film-shaped wiring body; Is a liquid crystal display device connected by an anisotropic conductive film, characterized in that an adhesive layer is provided between the electrode terminal portion and the film-shaped wiring body so as to adhere them.

The adhesive layer is a thermosetting resin.

A method of manufacturing a liquid crystal display device according to the present invention is the method of manufacturing a liquid crystal display device according to claim 1, wherein the anisotropic conductive film is formed at a predetermined position on the electrode terminal portion.
Further, a step of forming the adhesive layer at a position different from the position at which the anisotropic conductive film is formed on the electrode terminal portion, and forming the anisotropic conductive film and the adhesive layer over the electrode terminal portion at: Superposing the film-shaped wiring body at a predetermined position and applying a thermal pressure from above the film-shaped wiring body.

The conditions for applying the thermal pressure are as follows:
180 ° C., pressure 20-40 kg / cm ² , time 20-3
0 seconds.

An electrode wiring board according to the present invention comprises a substrate having electrodes formed on a surface thereof, and a film substrate having electrodes formed on a surface thereof. Is an electrode wiring substrate connected by a conductive layer, wherein an adhesive layer for bonding the two is provided between the substrate and the film-like substrate.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic sectional view showing the structure of a main part of a liquid crystal display device according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view showing a liquid crystal panel used in the liquid crystal display device. is there. As shown in FIG. 2, the liquid crystal panel 1 has a first transparent substrate 11a and a second transparent substrate 11b made of glass or the like.
The first transparent substrate 11a and the second transparent substrate 11b are arranged so as to face each other in parallel. A side edge along one side of the second transparent substrate 11b extends to the outside of the first transparent substrate 11a. On the side edge, the electrode terminal portion 17 faces the first transparent substrate 11a. Is formed.

On the surface of the first transparent substrate 11a opposite to the second transparent substrate 11b, pixel electrodes 12a of respective picture elements made of an ITO (indium tin oxide) film or the like are provided in a matrix at a predetermined interval. The alignment film 13a is formed so as to cover the pixel electrode 12a. A counter electrode 12b made of an ITO (indium tin oxide) film or the like is formed on the entire surface of the second transparent substrate 11b, and an alignment film 13b is formed on a region of the counter electrode 12b other than the electrode terminal portion 17. Is formed. Alignment films 13a and 13
b is provided on the first transparent substrate 11a and the second transparent substrate 11b so as to face each other.

First transparent substrate 11a and second transparent substrate 1
1b between the alignment films 13a and 13b.
4 is filled, and the liquid crystal layer 14 is made of alignment films 13a and 13a.
It is sealed by a sealant 15 made of an insulating resin provided between the outer peripheral edges of the portion b. Also, the first transparent substrate 1
Polarizing plates 16a and 16b are provided on the surface of 1a and the second transparent substrate 11b opposite to the liquid crystal layer 14 so as to correspond to the liquid crystal layer 14, respectively.

In the liquid crystal display device of the present invention, as shown in FIG. 1, a circuit board 2 on which a driving element for driving the liquid crystal panel 1 and the like are mounted is disposed close to an electrode terminal portion 17 of the liquid crystal panel 1. The liquid crystal panel 1 and the circuit board 2 are electrically connected by a film wiring body 3 made of TAB or FPC. The film-shaped wiring body 3 is an insulating film made of a polyimide film or the like, and a large number of foil-shaped lead wires 31 are formed on the surface of the film-shaped wiring body 3.

The electrode terminal portion 17 formed on one side edge of the second transparent substrate 11b is formed so as to face one side edge of the film-shaped wiring body 3 and the vicinity thereof. First transparent substrate 1 in film-shaped wiring body 3
An anisotropic conductive film 5 is provided between a side edge portion close to 1 a and the electrode terminal portion 17. And anisotropic conductive film 5
Counter electrode 12b provided on the electrode terminal portion 17
And a foil-like lead wire 31 provided on the film-like wiring body 3
And are electrically connected.

An adhesive layer 7 is provided between the side edge of the electrode terminal 17 along the side surface of the second transparent substrate 11b and the film wiring body 3. And the electrode terminal part 17 and the film-shaped wiring body 3 are mechanically fixed by the adhesive layer 7. This prevents the anisotropic conductive film 5 from peeling off from the electrode terminal portion 17.

One end of the circuit board 2 is connected to the other end of the film-shaped wiring body 3 on the surface of which the foil-shaped lead wire 31 is formed via a soldered portion 6 made of solder. . The circuit board 2 is an insulating substrate made of glass epoxy or the like.
1 is formed. The circuit pattern 21 and the foil-shaped lead 31 are electrically connected by the soldering portion 6.

The anisotropic conductive film 5 is formed into a film by mixing fine conductive metal particles such as solder, nickel, and carbon in a binder such as a thermoplastic resin or a thermosetting resin. And the thickness is 20 to 30 μm. The adhesive layer 7 is formed of a thermosetting resin in a film shape, and has a thickness of 20 to 30 μm.

Next, a description will be given of a manufacturing method for connection between the liquid crystal panel 1 and the film wiring body 3 and connection between the film wiring body 3 and the circuit board 2 of the liquid crystal display device of the present invention.

First, in the liquid crystal panel 1, the electrode terminal portion 1 provided on one side edge of the second transparent substrate 11b is provided.
7, a film-shaped anisotropic conductive film 5
Is formed, and a film-like adhesive layer 7 is further formed.
The anisotropic conductive film 5 is formed on the counter electrode 12b near the side surface of the end of the first transparent substrate 11a, and the adhesive layer 7 is formed on the opposite side of the electrode terminal 17 near the end of the second transparent substrate 11b. Electrode 1
2b.

Next, the film-shaped wiring body 3 having the foil-shaped lead wire 31 formed on the surface is placed in a different position with the predetermined position of the foil-shaped lead wire 31 facing the anisotropic conductive film 5 and the adhesive layer 7. It overlaps with the isotropic conductive film 5 and the adhesive layer 7. In this state, the anisotropic conductive film 5 and the adhesive layer 7 on the electrode terminal portion 17 are
When a thermal pressure is applied (thermocompression bonding) via the film-like wiring body 3 to the counter electrode 12b on the electrode terminal portion 17,
And the foil-like lead wire 31 on the film-shaped wiring body 3 are electrically connected by the anisotropic conductive film 5, and the electrode terminal portions 17 and the film-shaped wiring body 3 are bonded by the adhesive layer 7 and mechanically connected. Fixed to The conditions for applying heat pressure (thermocompression bonding) are as follows: temperature 150-180 ° C., pressure 20-40 kg /
It is preferably performed in cm ^{2 for} a time of 20 to 30 seconds.

Next, the foil-like lead wire 31 formed on the film-like wiring body 3 and the circuit pattern 21 on the circuit board 2 are overlapped at a predetermined position, and the film-like wiring body 3 and the circuit board 2 are joined. The connection is made by the soldering section 6. Thereby, the liquid crystal display device of the present invention is completed.

As described above, since the adhesive layer 7 can be formed by applying a thermal pressure (thermocompression bonding) simultaneously with the anisotropic conductive film 5, the conventional reinforcing resin coating step is not required, and Simplification and automation can be achieved, and effective connection strength can be obtained.

[0032]

The liquid crystal display device of the present invention comprises a liquid crystal panel, a circuit board, and a film-shaped wiring body for connecting the liquid crystal panel and the circuit board, and has electrode terminals provided on one side of the liquid crystal panel. The portion and the film-shaped wiring body are connected by an anisotropic conductive film, and further, an adhesive layer for bonding them is provided between the electrode terminal portion and the film-shaped wiring body. Without increasing the amount of conductive film used,
Effective connection strength is obtained.

According to the method of manufacturing a liquid crystal display device of the present invention, an anisotropic conductive film and an adhesive layer are formed at different positions on an electrode terminal portion, and the anisotropic conductive film and the adhesive layer are
By superposing the film-shaped wiring bodies at predetermined positions and applying heat pressure through the film-shaped wiring bodies, the application of the reinforcing resin becomes unnecessary, and the simplification of the process and automation can be easily achieved.

In the electrode wiring board of the present invention, a substrate having electrodes formed on the surface thereof and a film-shaped substrate having electrodes formed on the surface are connected by a conductive layer. Between them, an adhesive layer for adhering them is provided, so that it is possible to repair when a connection failure occurs after the product is completed.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a structure of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view showing a liquid crystal panel used in the liquid crystal display device of FIG.

FIG. 3 is a schematic sectional view showing a structure of a conventional liquid crystal display device.

FIG. 4 is a schematic sectional view showing the structure of another conventional liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal panel 2 Circuit board 3 Film wiring body 4 Reinforcement resin 11a 1st transparent substrate 11b 2nd transparent substrate 12a Picture element electrode 12b Counter electrode 13a Alignment film 13b Alignment film 14 Liquid crystal layer 15 Sealant 16a Polarizer 16b Polarizer 17 Electrode terminal part 21 Circuit pattern 31 Foil-shaped lead wire

Claims (5)

[Claims] 1. A liquid crystal panel having a liquid crystal layer provided between a pair of transparent substrates, a circuit board having driving elements for driving the liquid crystal panel, and a film connecting the liquid crystal panel and the circuit board. A liquid crystal panel, wherein an electrode terminal provided on at least one side edge of the liquid crystal panel and one side edge of the film-shaped wiring body are connected by an anisotropic conductive film. A liquid crystal display device, comprising: a display device, wherein an adhesive layer for bonding the two is provided between the electrode terminal portion and the film-shaped wiring body. 2. The liquid crystal display according to claim 1, wherein the adhesive layer is a thermosetting resin. 3. The method for manufacturing a liquid crystal display device according to claim 1, wherein said anisotropic conductive film is formed at a predetermined position on said electrode terminal portion, and further comprising: Forming the adhesive layer at a position different from the position at which the anisotropic conductive film is formed; and forming the anisotropic conductive film and the adhesive layer on the electrode terminal portion,
A method of superposing a film-shaped wiring body at a predetermined position and applying a thermal pressure from above the film-shaped wiring body. 4. The condition for applying the thermal pressure is a temperature of 150.
~ 180 ° C, pressure 20 ~ 40kg / cm ² , time 20 ~
The method according to claim 3, wherein the time is 30 seconds. 5. A substrate having an electrode formed on a surface thereof, and a film substrate having an electrode formed on a surface thereof, wherein the electrode on the substrate and the electrode on the film substrate are connected by a conductive layer. An electrode wiring board, characterized in that an adhesive layer for bonding the two is provided between the substrate and the film-shaped substrate.