JP2001119116A - Connecting structure for liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connecting structure which is used for connecting the liquid crystal panel and the liquid crystal driver IC of a liquid crystal display device to each other and can prevent the occurrence of short-circuiting failures, even when conductive contamination adhere between adjacent patterned wiring formed on the flexible insulating film of the liquid crystal driver I/C by covering the exposed section of the patterned wiring. SOLUTION: In a connecting structure, an insulating film (B) 6 is formed so as to cover patterned wiring (A) 3 formed on the flexible insulating film 2 of a liquid crystal driver IC 1 and the conductive particles 22 having plural projections of an anisotropic conductive film 21, made of an adhesive electrically connect the patterned wiring (A) 3 are formed on the insulating film 2 to patterned wiring (B) 13, formed on the glass substrate 12 of a liquid crystal panel 11 by breaking through the insulating film (B) 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a connection structure for a liquid crystal display device, and more particularly to a connection structure between a liquid crystal panel of a liquid crystal display device and a liquid crystal driver IC.

[0002]

2. Description of the Related Art A connection structure between a liquid crystal panel and a liquid crystal driver IC of a conventional liquid crystal display device is schematically shown in FIG.
A partially cut bottom view of FIG. First, as shown in FIG. 5, the liquid crystal driver IC 1 is connected to a pattern wiring (A) 3 formed of copper foil on a flexible insulating film 2 made of, for example, polyimide as a base material.
Are sealed so as to be covered with a sealing resin 4 for protection including a connection portion with the pattern wiring (A) 3. The pattern wiring (A) 3 is provided with tin plating on the surface of the copper foil to prevent oxidation. Further, for protection of the surface of the pattern wiring (A) 3, except for one end of the pattern wiring (A) 3, which is a connection portion with the liquid crystal panel, for example, an insulating film (A) 5 coated with a resist covers the entire surface. It is formed to cover.

The liquid crystal panel 11 is formed on a glass substrate 12 which is a transparent substrate. Then, a pattern wiring (B) 13 which is a connection wiring to the liquid crystal driver IC 1 is formed on one end of the glass substrate 12 by, for example, chrome wiring.

The pitch p (a) of the pattern wiring (A) 3 formed on the flexible insulating film 2 of the liquid crystal driver IC 1 and the pattern wiring (formed on the glass substrate 12 of the liquid crystal panel 11) B) The pitch p (b) of 13 is the same at its connection as shown in FIG.

Then, the liquid crystal panel 11 and the liquid crystal driver I
As shown in FIGS. 5 and 6, the connection structure with C1 has an anisotropic conductive film (Ani) having spherical conductive particles 22 and insulating resin binder 23 at the connection portion.
sotropic Conductive Film)
21 is used and pressed.

First, an anisotropic conductive film 21 is attached to a connection portion of a pattern wiring (B) 13 formed on one end of a glass substrate 12 of a liquid crystal panel 11 so as to cover the entire surface. The connection portion of the pattern wiring (B) 13 formed on one end of the glass substrate 12 of the liquid crystal panel 11 with the anisotropic conductive film 21 interposed therebetween, and the flexible insulating film 2 of the liquid crystal driver IC 1 The connection portion, which is formed on the top and is not covered with the insulating film (A) 5, that is, one end of the pattern wiring (A) 3 is opposed to and aligned.

The glass substrate 12 of the liquid crystal panel 11 aligned with the anisotropic conductive film 21 interposed therebetween.
Heat and pressure are applied to the connection part of the pattern wiring (B) 13 formed thereon and the connection part of the pattern wiring (A) 3 formed on the flexible insulating film 2 of the liquid crystal driver IC 1. . As a result, the conductive particles 22 of the anisotropic conductive film 21 are pressed against each other, and through the conductive particles 22, the pattern wiring (B) 13 formed on the glass substrate 12 of the liquid crystal panel 11 and the flexibility of the liquid crystal driver IC 1 are increased. The pattern wiring (A) 3 formed on the conductive insulating film 2 is electrically connected. The connection state is such that the resin binder 23 of the anisotropic conductive film 21 is thermally cured and one end of the glass substrate 12 of the liquid crystal panel 11 including the formed pattern wiring (B) 13 and the formed pattern wiring ( A) One end of the flexible insulating film 2 of the liquid crystal driver IC 1 including 3 is adhered and held.

[0008]

The connection structure between the liquid crystal panel 11 and the liquid crystal driver IC 1 of the conventional liquid crystal display device described above depends on the variation in the outer dimensions of the liquid crystal panel 11 and on the flexible insulating film 2 of the liquid crystal driver IC 1. The pattern formed on the flexible insulating film 2 of the liquid crystal driver IC 1 at the connection portion due to the variation in the application position of the resist which is the insulating film (A) 5 covering the surface of the pattern wiring (A) 3 formed An exposed portion where the wiring (A) 3 is not covered with the insulating film (A) 5 and the anisotropic conductive film 21 is not adhered occurs.

For this reason, as shown in FIG. 5 and FIG. 7, which is a schematic diagram for explaining the problems of the prior art, the liquid crystal driver I
In the exposed portion of the pattern wiring (A) 3 formed on the flexible insulating film 2 of C1, for example, a conductive foreign matter 31 such as solder dust is straddled over the adjacent pattern wiring (A) 3 in a later step. If they adhere, short-circuit failure occurs between the adjacent pattern wirings (A) 3.

For this reason, in order to prevent a short circuit defect caused by the adhesion of the conductive foreign matter 31 between the adjacent pattern wirings (A) 3 formed on the flexible insulating film 2 of the liquid crystal driver IC 1, After connecting the panel 11 and the liquid crystal driver IC 1 using the anisotropic conductive film 21, the exposed portion of the pattern wiring (A) 3 formed on the flexible insulating film 2 of the liquid crystal driver IC 1 is replaced with, for example, silicon resin or the like. Or covered with an insulating material such as silicone tape. Therefore, there is a problem that work efficiency is poor.

Therefore, an object of the present invention is to provide a liquid crystal driver I
C. A liquid crystal display device capable of efficiently covering an exposed portion of a pattern wiring formed on a flexible insulating film of C with an insulating material and preventing a short circuit even if conductive foreign matter adheres between adjacent pattern wirings. Liquid crystal panel and liquid crystal driver IC
And to provide a connection structure.

[0012]

A connection structure according to the present invention is a connection portion located at an end of a first wiring board, and comprises a flexible insulating film and a plurality of pattern wirings formed thereon. A connection part located at an end of a second wiring board connected to a connection part of the first wiring board, the connection part having an insulating substrate and a plurality of pattern wirings formed thereon And an adhesive for bonding and connecting a connection portion between the first wiring substrate and the second wiring substrate, wherein the first wiring substrate includes the connection portion and the adhesive. An insulating film formed so as to cover the plurality of pattern wirings formed on the flexible insulating film, the conductive particles of the anisotropic conductive film as the adhesive penetrate the insulating film, 1 Wiring board pattern Characterized in that electrically connects the line and pattern wiring of the second wiring board.

Further, the first wiring board has a liquid crystal driver IC of a liquid crystal display device connected to a pattern wiring formed on the flexible insulating film, and the liquid crystal driver I
C is sealed so as to be covered with a sealing resin, and the second wiring substrate is a liquid crystal panel formed on a transparent substrate which is an insulating substrate of the liquid crystal display device.

Further, the insulating film is a resist film,
It is formed by an offset printing method.

The insulating film is a low-viscosity, room-temperature curable resin, and is formed by being applied by a spray method.

The conductive particles are obtained by crushing a metal material and have a plurality of projections on the surface.

Further, the insulating film includes a first insulating film formed by exposing a connecting portion of the first wiring board, a connecting portion of the first wiring substrate, and the first insulating film. A second insulating film formed so as to cover the first insulating film;
The insulating film is a resist film.

According to the present invention, the liquid crystal driver I
The first wiring board to which C is connected has an insulating film formed so as to cover the plurality of pattern wirings formed on the flexible insulating film including the connection portion, and the exposed portion of the pattern wiring Is covered with an insulating film.

[0019]

Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a first embodiment of the invention.
FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. 3 is a sectional view taken along line BB of FIG.

The connection structure between the liquid crystal panel and the liquid crystal driver IC of the liquid crystal display device of the present embodiment is, as shown in FIG.
First, the liquid crystal driver IC 1 is connected to a pattern wiring (A) 3 formed of copper foil on a flexible insulating film 2 made of, for example, polyimide as a base material.
Are sealed so as to be covered with a sealing resin 4 for protection including a connection portion with the pattern wiring (A) 3. The pattern wiring (A) 3 is provided with tin plating on the surface of the copper foil to prevent oxidation. Further, for protection of the surface of the pattern wiring (A) 3, except for one end of the pattern wiring (A) 3, which is a connection portion with the liquid crystal panel, for example, an insulating film (A) 5 coated with a resist covers the entire surface. It is formed to cover. Further, the insulation is performed so as to cover one end of the pattern wiring (A) 3 and the entire surface of the insulating film (A) 5, that is, the exposed portion of the pattern wiring (A) 3. The film (B) is formed. Here, the insulating film (B) is formed by applying a resist with a thickness of several microns by, for example, an offset printing method, and curing by heating. Alternatively, the insulating film (B) is formed by applying a low-viscosity, room-temperature-curable silicone resin to a thickness of several microns by, for example, a spray method.

The liquid crystal panel 11 is formed on a glass substrate 12 which is a transparent substrate. Then, a pattern wiring (B) 13 which is a connection wiring to the liquid crystal driver IC 1 is formed on one end of the glass substrate 12 by, for example, chrome wiring.

Here, the pitch of the pattern wiring (A) 3 formed on the flexible insulating film 2 of the liquid crystal driver IC 1 and the pitch of the pattern wiring (B) 13 formed on the glass substrate 12 of the liquid crystal panel 11. The pitch is the same at the connection.

The liquid crystal panel 11 and the liquid crystal driver I
As shown in FIGS. 1, 2 and 3, the connection structure with C1 has an anisotropic conductive material having conductive particles 22 provided with a plurality of protrusions on the surface and insulating resin binder 23 at the connection portion. Film (Anisotropic Co
A negative film 21 is used and pressed. Here, the conductive particles 22 are obtained by, for example, crushing a metal material such as nickel and providing a plurality of protrusions on the surface.

First, the anisotropic conductive film 21 is attached to the connection portion of the pattern wiring (B) 13 formed on one end of the glass substrate 12 of the liquid crystal panel 11 so as to cover the entire surface. The connection portion of the pattern wiring (B) 13 formed on one end of the glass substrate 12 of the liquid crystal panel 11 with the anisotropic conductive film 21 interposed therebetween, and the flexible insulating film 2 of the liquid crystal driver IC 1 The connection portion, which is formed on the insulating film (B) 6 and is one end of the pattern wiring (A) 3 and is covered with the insulating film (B) 6, faces and aligns.

The glass substrate 12 of the liquid crystal panel 11 aligned with the anisotropic conductive film 21 interposed therebetween.
Heat and pressure are applied to the connection part of the pattern wiring (B) 13 formed thereon and the connection part of the pattern wiring (A) 3 formed on the flexible insulating film 2 of the liquid crystal driver IC 1. . As a result, the conductive particles 22 of the anisotropic conductive film 21 are pressed against each other, and the conductive particles 22 having a plurality of protrusions on the surface break through the insulating film (B) 6 covering the pattern wiring (A) 3. The pattern wiring (B) 13 formed on the glass substrate 12 of the liquid crystal panel 11 and the pattern wiring (A) 3 formed on the flexible insulating film 2 of the liquid crystal driver IC 1 via the conductive particles 22. Electrically connected. In this connection state, one end of the glass substrate 12 of the liquid crystal panel 11 including the formed pattern wiring (B) 13 and the insulating film (B) 6 including the formed pattern wiring (B) 13 are formed by curing the resin binder 23 of the anisotropic conductive film 21. One end of the flexible insulating film 2 of the liquid crystal driver IC 1 including the pattern wiring (A) 3 covered with and formed by is adhered and held.

FIG. 4 is a schematic diagram for explaining a second embodiment of the present invention. As shown in FIG. 4, the connection structure between the liquid crystal panel and the liquid crystal driver IC of the liquid crystal display device of this embodiment is the same as that of the first embodiment shown in FIG.
An insulating film (A) 5 is formed on the surface of the liquid crystal panel 3 so as to cover the entire surface except for one end of the pattern wiring (A) 3 which is a connection portion with the liquid crystal panel 11. The insulating film (B) 6 is formed so as to cover one end of the pattern wiring (A) 3 and the entire surface of the insulating film (A) 5, that is, to cover the exposed portion of the pattern wiring (A) 3. On the other hand, the insulating film (A) 5 is not formed on the surface of the pattern wiring (A) 3 and the pattern wiring (A)
Only the insulating film (B) 6 is formed so as to cover the entire surface of the pattern wiring (A) 3, that is, to cover the exposed portion of the pattern wiring (A) 3.

The liquid crystal panel 11 and the liquid crystal driver I
The connection structure using the anisotropic conductive film 21 at the connection portion with C1 is the same as that of the first embodiment shown in FIG.

[0028]

As described above, according to the present invention, the insulating film is formed before connecting the exposed portion of the pattern wiring formed on the flexible insulating film of the liquid crystal driver IC to the liquid crystal panel. As a result, it is possible to obtain an effect that the work efficiency is good and a short circuit failure can be prevented even if conductive foreign matter adheres between adjacent pattern wirings.

When only the insulating film (B) is formed,
Since there is no step in the insulating film, it is possible to prevent the insulating film (A) (resist) from running over the connection between the liquid crystal panel and the liquid crystal driver IC due to variations in the external dimensions of the liquid crystal panel as in the prior art. Is also obtained. Furthermore, since there is no step in the insulating film, it is possible to prevent the occurrence of a short circuit between adjacent pattern wirings formed on the liquid crystal panel due to condensation of conductive particles due to a dam action between the pattern wirings of the anisotropic conductive film. can get.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a first embodiment of a connection structure between a liquid crystal panel and a liquid crystal driver IC of a liquid crystal display device of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a schematic diagram illustrating a second embodiment of the present invention.

FIG. 5 is a schematic diagram illustrating a conventional technique.

FIG. 6 is a partial cut-away bottom view illustrating a conventional technique together with FIG. 5;

FIG. 7 is a schematic diagram illustrating a problem of the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid crystal driver IC 2 Flexible insulating film 3 Pattern wiring (A) 4 Sealing resin 5 Insulating film (A) 6 Insulating film (B) 11 Liquid crystal panel 12 Glass substrate 13 Pattern wiring (B) 21 Anisotropic conductive film 22 conductive particles 23 resin binder 31 conductive foreign matter

Claims (10)

[Claims] A connection portion located at an end of the first wiring board, the connection portion having a flexible insulating film and a plurality of pattern wirings formed thereon; A connection portion located at an end of a second wiring board connected to the connection portion, the connection portion having an insulating substrate and a plurality of pattern wirings formed thereon;
And a bonding agent for bonding and connecting the connection portions of the wiring board and the second wiring board,
The first wiring board has an insulating film formed so as to cover a plurality of pattern wirings formed on the flexible insulating film including the connection portion, and the adhesive is an anisotropic conductive film. A connection structure, wherein the conductive particles of (1) penetrate the insulating film and electrically connect the pattern wiring of the first wiring board and the pattern wiring of the second wiring board. 2. The first wiring board according to claim 1, wherein a liquid crystal driver IC of the liquid crystal display device is connected to a pattern wiring formed on the flexible insulating film, and the liquid crystal driver IC is covered with a sealing resin. Is sealed in
2. The liquid crystal panel formed on a transparent substrate, which is an insulating substrate of the liquid crystal display device, wherein the second wiring substrate is provided.
Connection structure described. 3. The connection structure according to claim 1, wherein said insulating film is a resist film. 4. The connection structure according to claim 3, wherein said insulating film is formed by an offset printing method. 5. The connection structure according to claim 1, wherein the insulating film is a low-viscosity cold-setting resin. 6. The connection structure according to claim 5, wherein the insulating film is formed by being applied by a spraying method. 7. The connection structure according to claim 1, wherein the conductive particles have a plurality of protrusions on a surface. 8. The connection structure according to claim 7, wherein the conductive particles are obtained by crushing a metal material, and a plurality of protrusions are provided on a surface thereof. 9. The first insulating film formed by exposing a connection portion of the first wiring board, wherein the first insulating film is formed by exposing a connection portion of the first wiring board.
6. The connection structure according to claim 1, further comprising a second insulating film formed so as to cover the connection portion of the wiring board and the first insulating film. 10. The connection structure according to claim 9, wherein said first insulating film is a resist film.