JP2507005Y2 - Liquid crystal display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a liquid crystal display device in which a substrate having a transparent electrode and a substrate having a transparent electrode and a lead wiring portion are electrically connected by an anisotropic conductive sealing material. Regarding the structure.

[Conventional technology]

As a conventional example of a structure for electrically connecting a substrate having a transparent electrode to a substrate having a transparent electrode and a lead wiring portion,
There is a structure shown in the figure. 4 (a), (b), (c)
Will be explained. FIG. 4 (a) is a plan view showing a liquid crystal display device, FIG. 4 (b) is an enlarged cross-sectional view of a connection region connected by an anisotropic conductive seal, and FIG. 4 (c) is anisotropic. It is the top view which expanded the connection area | region by a conductive seal. A second substrate having a transparent electrode 203 on a first substrate 201.
A transparent electrode 204 and a lead wiring portion 205 are provided on the 202. The IC 206 is mounted on the second substrate 202. The first substrate 201 and the second substrate 202 are opposed to each other with a predetermined distance on the surface having the transparent electrodes 203 and 204, and the periphery thereof is sealed with an anisotropic conductive sealing material 207. Transparent electrode on the second substrate 202
204 is connected to the IC 206 by a lead wiring portion 205.

On the other hand, the transparent electrode 203 on the first substrate 201 is electrically connected to the lead wiring portion 205 via the anisotropic conductive sealing material 207 and connected to the IC 206. The anisotropic conductive sealing material 207 is the sealing material 208
And conductive particles 209 and a non-conductive substance 210 having a particle diameter smaller than that of the conductive particles 209.

[Problems to be solved by the device]

In recent years, the wiring pitch of the transparent electrodes 203 and 204 of the liquid crystal display device is in the direction of miniaturization and densification, and in the above-described conventional method, the conductive particles 209 and the non-conductive substance 210 of the anisotropic conductive sealing material 207 are used. When the pitch of the transparent electrode 203 and the lead-out wiring portion 205 is reduced without changing the particle size of the transparent electrode 203, as shown in FIG. 5, the conductive particles 209 in the anisotropic conductive sealing material 207 are adjacent to the transparent electrode 203. The probability of short-circuiting across the space is extremely high. Although it is conceivable to reduce the particle size of the conductive particles 209, if the particle size is smaller than that of the non-conductive substance 210, the probability that the transparent electrode 203 and the lead-out wiring portion 205 cannot be electrically connected becomes extremely high, which is not preferable. It is also possible to reduce the particle size of the non-conductive substance 210 and the particle size of the conductive particles 209. In this case, an appropriate cell gap 211 of the liquid crystal display device shown in FIG. 4B is secured. Difficult to do. For the above reasons, in the structure of the conventional liquid crystal display device using the anisotropic conductive sealing material, it is difficult to make the wiring pitches of the transparent electrodes 203, 204 and the lead-out wiring portion 205 finer and higher in density. The pitch of the transparent electrodes 203, 204 and the lead wiring portion 205 is limited to about 30 μm.

It is an object of the present invention to solve the above problems and to reduce the pitch of the transparent electrodes and the lead-out wiring portions.

[Means for solving the problem]

In order to achieve the above object, the liquid crystal display device of the present invention has the following configuration. An anisotropic conductive sealing material is used for the first substrate having the transparent electrode and the second substrate having the transparent electrode and the lead wiring portion, and the transparent electrode of the first substrate and the lead wiring portion of the second substrate are used. In a liquid crystal display device that is electrically connected to a transparent electrode, an anisotropic conductive sealing material has an insulating film in a region in contact with the transparent electrode.

〔Example〕

Hereinafter, one embodiment according to the present invention will be described with reference to FIG.
A description will be given based on (b) and (c).

1A is a plan view showing a liquid crystal display device, FIG. 1B is an enlarged cross-sectional view of a connection region by an anisotropic conductive seal material, and FIG. 1C is an anisotropic conductive seal. It is the top view which expanded the connection area | region by the material. The transparent electrode 103 is provided on the first substrate 101, and the transparent electrode 104 and the lead wiring portion 105 are provided on the second substrate 102. IC 106 is the second substrate 102
Implemented on. The first substrate 101 and the second substrate 102 are opposed to each other with a predetermined distance therebetween on the surfaces having the transparent electrodes 103 and 104, and the periphery thereof is sealed with an anisotropic conductive sealing material 107. The transparent electrode 104 on the second substrate 102 is a lead wiring portion 105.
Is connected to IC 106 by. On the other hand, the transparent electrode 103 on the first substrate 101 is electrically connected to the lead wiring portion 105 via the anisotropic conductive sealing material 107 and connected to the IC 106. The anisotropic conductive sealing material 107 includes a sealing material 108, conductive particles 109, and the conductive particles 109.
It is made of a non-conductive material 110 having a smaller particle size. The transparent electrode 103 on the first substrate 101 is connected to the lead wiring portion 105 on the second substrate 102 via conductive particles 109. An insulating film 111 is provided below the lead wiring portion 105 that is in contact with the anisotropic conductive seal material 107. Therefore, the transparent electrode 10 on the first substrate 101
The distance between 3 and the lead wiring portion 105 on the second substrate 102 becomes smaller than the cell gap 114 of the liquid crystal display device. Therefore, the conductive particles 109 included in the anisotropic conductive sealing material 107 can be the conventional conductive particles 109 having a diameter of 2 μm to 10 μm to 2 μm or less. Transparent electrode 103 of first substrate 101
It is possible to connect the lead wiring portion 105 of the second substrate 102 and the lead wiring portion 105 with a wiring pitch of about 10 μm. As a minimum value, the wiring pitch of the transparent electrode 103 and the lead wiring portion 105 is about 5 μm.
Even if the structure is miniaturized and the density is increased, a stable connection between the transparent electrode 103 and the lead wiring portion 105 can be obtained without causing a short circuit or an open. As for the structure of the insulating film 111, in the case of a passive type monochrome display device in which each pixel electrode does not have a switching element, the insulating film 111 includes the transparent electrode 104 and the lead wiring portion 10.
It is necessary to form it on the second substrate 102 before forming 5, and it is possible to use epoxy or the like which is a normal sealing material. In the case of an active type liquid crystal display device having a switching element in each pixel electrode, it is possible to simultaneously form the insulating film used in the pixel by photoetching using SiO ₂ , SiN or the like. FIG. 2 is a cross-sectional view of FIG. 1 (b) viewed from the lateral direction rotated by 90 °, and in this case, the insulating film 111 is located only under the lead-out wiring portion 105, but on the entire surface of the second substrate 102. The configuration in can be used. In the case of a color liquid crystal display device, the insulating film 111 is a color filter used in the liquid crystal display device as shown in FIG.
It is also possible to form the insulating film 111 by using 113 or the protective film 112 for protecting the color filter 113, or a combination thereof. The anisotropic conductive sealing material 107 includes a sealing material 108 made of an epoxy resin, plastic beads made of a copolymer of styrene and divinylbenzene having different compositions, and one or more metals such as Ni, Al, Au and Ag. Conductive particles 109 formed by plating in combination with a non-conductive substance 110 made of glass fibers or beads made of an inorganic oxide (SiO ₂ etc.) or organic beads having high hardness (polymethyl methacrylate etc.) Composed of and. Although the example in which the insulating film 111 is formed on the second substrate 102 has been described, the insulating film 111 may be formed on the first substrate 101.

[Effect of device]

As is apparent from the above description, the present invention has a structure in which an insulating film is provided between the transparent electrode in contact with the anisotropic conductive sealing material and the substrate in the liquid crystal display device, thereby providing a transparent electrode and a lead wiring portion. The distance can be reduced. as a result,
The particle diameters of the conductive particles and the non-conductive substance, which are the constituent materials of the anisotropic conductive sealing material, can be reduced. Therefore, about 1/6 of the conventional
It is possible to connect the transparent electrode and the lead-out wiring portion with the anisotropic conductive sealing material at the following pitches. Moreover, since the particle diameters of the conductive particles and the non-conductive material are made fine, the anisotropic conductive seal width can be reduced to about one half. Therefore, the size of the liquid crystal display device can be reduced by the seal width.

[Brief description of drawings]

1 (a) to 1 (c) are views showing a liquid crystal display device according to a first embodiment of the present invention, and FIG. 1 (a) is a plan view,
FIG. 1 (b) is a cross-sectional view showing a connection region by an anisotropic conductive sealing material, FIG. 1 (c) is an enlarged plan view of a connection region by an anisotropic conductive sealing material, and FIG. 2 is FIG. 3B is a cross-sectional view of the liquid crystal display device according to the second embodiment of the present invention when viewed from different directions, and FIG. 3A is a cross-sectional view showing a connection region by an anisotropic conductive sealing material. c) shows a liquid crystal display device in a conventional example, FIG. 4 (a) is a plan view, FIG.
FIG. 4 (b) is a cross-sectional view showing a connection region formed by an anisotropic conductive sealing material, FIG. 4 (c) is an enlarged plan view of the connection region formed by an anisotropic conductive sealing material, and FIG. It is a top view for explaining the subject of a device. 101 ... First substrate, 102 ... Second substrate, 103, 104 ... Transparent electrode, 105 ... Lead-out wiring portion, 106 ... IC, 107 ... Anisotropic conductive sealing material, 111 ... Insulating film .

Claims (1)

(57) [Scope of utility model registration request] 1. A first substrate having a transparent electrode and a second substrate having a transparent electrode and a lead-out wiring portion are formed by using an anisotropic conductive sealing material, and the transparent electrode of the first substrate and the second substrate. Electrical connection with the lead-out wiring part of the
In a liquid crystal display device in which the substrate is opposed to the other substrate via a cell gap, an anisotropic conductive sealing material is provided by providing an insulating film between the transparent electrode and the first substrate or between the lead wiring portion and the second substrate. A liquid crystal display device characterized in that the connection area in the cell is smaller than the cell gap.