JP2553940Y2 - Liquid crystal display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application field] In the present invention, a transparent electrode provided on one substrate and a lead-out wiring provided on the other substrate are formed by an anisotropic conductive sealing material. The present invention relates to a liquid crystal display device which is electrically connected.

[Conventional technology]

2. Description of the Related Art Conventionally, a liquid crystal display device having a structure shown in FIG. 2A is known. This liquid crystal display device has two substrates 20 provided with transparent electrodes 211 and 213 (not shown).
The IC chip 205 is mounted on only one of the substrates 203 among the substrates 1 and 203. The transparent electrode 213 (not shown) on the substrate 203 is connected to the IC chip 205 by the lead-out wiring 207. On the other hand, the transparent electrode 211 (not shown) of the substrate 201 is electrically connected to the lead wiring 209 on the substrate 203 via the conductive material 217, and the IC chip
Connected to 205.

 FIG. 2B is a sectional view of the liquid crystal display device.

Here, transparent electrodes 211 and 213 are provided on the substrates 201 and 203, respectively.
Are arranged. This liquid crystal display device has a substrate 201 and a substrate 2
03 are spaced apart from each other by a predetermined distance on the surface on which the transparent electrodes 211 and 213 are provided, and the periphery is sealed with a sealing material 215. Liquid crystal (not shown) is sealed in a portion formed by the substrates 201 and 203 and the sealant 215. The transparent electrode 211 on the substrate 201 is electrically connected to the lead wiring 209 on the substrate 203 via the conductive material 217.

[Problems to be solved by the invention]

FIG. 2 (c) is an explanatory view of the pattern of the conductive material 217. Each conductive material 217 is partitioned for each transparent electrode 211 (not shown) or each lead wire 209 (not shown) to prevent a short circuit between adjacent conductive materials 217. here,
In general, a sealing material 215 is used for partitioning the conductive material 217. The liquid crystal display device having such a structure requires a process of disposing the conductive material 217 and a process of disposing the sealant 215 in the manufacturing process, and the manufacturing is not easy.

In recent years, high-density display has been required, and accordingly, the pattern of the conductive material 217 has been miniaturized. However, in the liquid crystal display device having the above structure, each conductive material 217 must be partitioned, and
High precision is required due to the alignment of the sealing material 215 and the like, and it has been difficult to manufacture by conventional screen printing or the like.

Further, the conventional conductive material 217 is composed of a thermosetting resin having Al powder and Ag.
Powder, C powder and the like were mixed, and the durability against compression was poor. For this reason, a sufficient margin for compression could not be obtained in the portion where the conductive material 217 is provided.

An object of the present invention is to provide a liquid crystal display device which solves such a problem, has a simple manufacturing method, sufficiently obtains continuity between a transparent electrode and a lead wiring, and has a high margin for a compressive force. .

[Means for solving the problem]

In the liquid crystal display device of the present invention, the first substrate on which the transparent electrode is disposed and the second substrate on which the transparent electrode and the lead-out wiring are disposed face each other at a predetermined distance on the surface on which the transparent electrode is disposed. The periphery thereof is sealed with an anisotropic conductive sealing material obtained by mixing conductive particles having elasticity and a non-conductive substance smaller than the particle diameter of the conductive particles with the sealing material.

[Action]

The anisotropic conductive sealing material constituting the liquid crystal display device of the present invention has conductivity in the thickness direction and does not have conductivity in the lateral direction.

The conductive particles having elasticity are used to establish electrical continuity between the transparent electrode and the lead wiring, and Ni, Al, A
Plates of one or more selected from u and Ag can be used. As the plastic beads, a copolymer of styrene and divinylbenzene is preferable.
The particle size is preferably 2 to 10 μm. In addition, since the conductive particles also function as spacers and have elasticity, the margin of the liquid crystal display device against the compressive force can be improved.

The non-conductive substance is intended to improve the dispersibility of the conductive particles in the anisotropic conductive sealing material, and organic substances such as plastic beads, and inorganic substances such as glass fibers and metal oxides can be used. . For example, plastic beads include a copolymer of styrene and divinylbenzene, and metal oxides include SiO ₂ . The size of the non-conductive substance may be smaller than the particle size of the conductive particles in order to establish conduction between the transparent electrode and the lead wiring. More preferably, the size of the non-conductive substance is within the elastic limit range of the conductive particles, and is about 95 to 75% of the particle size of the conductive particles. Further, by using glass fibers or inorganic beads having high hardness as a non-conductive substance, or by using plastic beads having high hardness by changing the composition of plastic beads (for example, the composition ratio of styrene and divinylbenzene), It is possible to improve the margin of the display device against the compressive force. Similarly, by increasing the dispersibility of the non-conductive substance in the conductive sealing material when the liquid crystal display device is compressed, the margin of the liquid crystal display device with respect to the compressive force can be further improved.

As a sealing material, an inorganic material such as a glass paste,
Organic resins such as epoxy resins and polyester resins which are thermosetting resins can be used.

The ratio of the conductive particles to the sealing material is 1% by weight or more, and preferably 1 to 5 from the connection establishment between the transparent electrode and the lead-out wiring.
% By weight. Beyond this range, the probability that a plurality of conductive particles continue in a chain and cause short-circuiting between the transparent electrodes or between the lead-out wirings becomes high, so that it cannot be used as a liquid crystal display device.

The ratio of the non-conductive substance to the sealing material is 5 to 30% by weight, preferably about 10% by weight.

A similar anisotropic conductive sealing material can be obtained by mixing only the conductive particles having elasticity into the sealing material. However, in such an anisotropic conductive sealing material, a plurality of conductive particles are connected in a chain and are close to each other. There is a high probability that a short circuit will occur between the electrodes or between the lead wires, and it cannot be used particularly for a liquid crystal display device having a fine transparent electrode pitch. In addition, when a pressure exceeding the elastic limit of the conductive particles is applied to the liquid crystal display device sealed with the anisotropic conductive sealing material in which such a non-conductive substance is not mixed, the conductive particles are destroyed and the transparent particles are transparent. It is no longer possible to obtain continuity between the electrode and the lead wiring, and it is not possible to maintain the distance between the substrates.

〔Example〕

Hereinafter, the liquid crystal display device of the present invention will be described based on embodiments. FIG. 1A is a view showing the liquid crystal display device of the present invention. Transparent electrode 105 (not shown) on first substrate 103
The transparent electrode 109 (not shown) and the lead wires 111 and 113 are provided on the second substrate 107. The IC chip 115 is mounted on the second substrate 107. The first substrate 103 and the second substrate 107 face each other at a predetermined distance on the surface on which the transparent electrodes 105 and 109 are provided, and the periphery is sealed with an anisotropic conductive sealing material 101. Transparent electrode 10 on second substrate 107
Reference numeral 9 (not shown) is connected to an IC chip 115 by a lead wiring 113. On the other hand, the transparent electrode 105 (not shown) on the first substrate 103 is connected to the lead wiring 1 via the anisotropic conductive sealing material 101.
11 and is connected to the IC chip 115.

The present invention is not limited to the liquid crystal display device shown in FIG. 1A, but can be applied to a liquid crystal display device having an IC chip mounted on one substrate.

FIG. 1B is a cross-sectional view around the anisotropic conductive sealing material 101. A transparent electrode 105 is provided on a first substrate 103, and a transparent electrode 109 and a lead-out wiring are provided on a second substrate 107.
111 are provided. Anisotropic conductive sealing material 101 is composed of sealing material 121, conductive particles 123, non-conductive substance 125,
The transparent electrode 105 and the lead wiring 111 are electrically connected.

The liquid crystal display of the present invention can be manufactured by a conventional manufacturing method. In the conventional manufacturing method, anisotropically mounting is performed on either the first substrate 103 provided with the transparent electrode 105 or the second substrate 107 provided with the transparent electrode 109 and the lead wires 111 and 113. In general, a conductive sealing material 101 is provided and bonded to the other substrate while applying pressure. In the liquid crystal display device manufactured in this way, the thickness of the anisotropic conductive sealing material 101 is determined by the particle size of the conductive particles 123 or the size of the non-conductive substance 125, so that the conductive particles 1
The conduction between the transparent electrode 105 and the lead-out wiring 111 can be sufficiently achieved via the wiring 23.

As an example of the manufacturing method, a method of manufacturing the liquid crystal display device of the present invention by screen printing will be described below. Conductive particles obtained by Au plating on plastic beads made of a copolymer of styrene and divinylbenzene are used as conductive particles 123 having elasticity. Copolymerization of styrene and divinylbenzene having different compositions from conductive particles is used as nonconductive substance 125. Plastic beads made of united material, an epoxy resin is used as the sealing material 121, and the anisotropic conductive sealing material 101 is formed by roll kneading.
Was obtained at a viscosity of 300 ps. Transparent electrode 109 and extraction wiring 11
1, anisotropic conductive sealing material 101 is disposed at a predetermined position on a screen on a second substrate 107 disposed on 113, and the first substrate 103 is pasted after pre-baking, and then fired and pressed. The liquid crystal display of the present invention can be manufactured. However, the manufacturing method is not limited to the above method.

The first case is when pressure is applied to the liquid crystal display device of the present invention.
It is shown in FIG. The conductive particles 123 also have a function as a spacer and have elasticity, so that they are not easily broken by pressure. The non-conductive substance 125 also has a function as a spacer, preventing the conductive particles from being broken by pressure and preventing the thickness of the anisotropic conductive sealing material 101 from changing.

Here, if the size of the non-conductive substance 125 is set to 95 to 75% of the particle size of the conductive particles within the elastic limit of the conductive particles 123, the effect of preventing the conductive particles 123 from being broken by pressure or the like is enhanced, and Through the particles 123, sufficient conduction between the transparent electrode 105 and the extraction wiring 111 can be obtained.

FIG. 1D is a sectional view taken along line AA in FIG. 1B. The presence of the non-conductive substance 125 improves the dispersibility of the conductive particles 123, and there is almost no short circuit between the adjacent transparent electrodes 105 or between the lead wirings 111.

[Effect of the invention]

The anisotropic conductive sealing material constituting the liquid crystal display device of the present invention is obtained by mixing conductive particles having elasticity and a non-conductive substance smaller than the particle size of the conductive particles into the sealing material. By using, the conduction between the transparent electrode and the lead wiring can be sufficiently obtained. Further, the anisotropic conductive sealing material has all the functions as a conductive material, a sealing material, and a spacer, which have conventionally been provided by separate members. Further, since the conductive particles have elasticity, the margin of the liquid crystal display device against the compressive force can be improved. In addition, a non-conductive substance having a high hardness is used to prevent the destruction of the conductive particles, or the dispersibility of the non-conductive substance in the anisotropic conductive sealing material when pressure is applied to the liquid crystal display device. By increasing the height, the margin of the liquid crystal display device with respect to the compressive force can be improved.

In addition, the non-conductive substance has an effect of improving the dispersibility of the conductive particles in the anisotropic conductive sealing material, and has the effect of preventing a short circuit between wirings due to a plurality of conductive particles connected in a chain.

The liquid crystal display of the present invention can be manufactured by a conventional manufacturing method. In particular, since the anisotropic conductive sealing material has the three functions as described above, two steps of arranging the conductive material and the sealing material in the past were achieved in one step of arranging the conductive sealing material. it can.

The liquid crystal display device of the present invention can be manufactured by a conventional simple manufacturing method and in a small number of steps, and the conduction between the transparent electrode and the lead wiring can be sufficiently achieved. What you can get. Also. The liquid crystal display device of the present invention is easy to manufacture because the mounting process of the IC chip is only required on one substrate. Further, in the case of the liquid crystal display device of the present invention, the substrate on which the IC chip is not mounted can be made thinner, and when applied to a reflection type liquid crystal display device, a liquid crystal display device with further improved appearance can be obtained.

[Brief description of the drawings]

FIG. 1 shows a liquid crystal display device according to an embodiment of the present invention,
(A) is a schematic plan view, (b) is a main part cross-sectional view, (c) is a cross-sectional view showing a case where pressure is applied to (b), (d) is an AA cross-sectional view of (b), FIG. 2 shows a conventional example,
(A) is a schematic plan view, (b) is a sectional view of a main part, and (c) is an explanatory view of a conductive material pattern. 101 ... conductive sealing material, 103, 105 ... board, 105, 109 ...
… Transparent electrode, 111, 113… lead-out wiring, 121… sealing material, 123… conductive particles, 125… non-conductive substance.

Claims (1)

(57) [Scope of request for utility model registration] 1. A first substrate on which a transparent electrode is disposed and a second substrate on which a transparent electrode and a lead-out wiring are disposed are spaced apart from each other by a predetermined distance with the surface on which the transparent electrode is disposed facing each other. The periphery is sealed with an anisotropic conductive sealing material, liquid crystal is injected into the sealing, and the transparent electrode of the first substrate and a part of the lead wiring of the second substrate are connected to the anisotropic conductive material. In a liquid crystal display device connected by conductive particles in a sealing material, the anisotropic conductive sealing material is slightly larger than the conductive particles having elasticity and the particle size of the conductive particles for enhancing the dispersibility of the conductive particles. A small non-conductive substance and a sealing material, wherein the ratio of the conductive particles to the sealing material is 1 to 5% by weight or / and the ratio of the non-conductive substance to the sealing material is 5 to 30% by weight. A difference characterized by a configuration mixed with the sealing material. The liquid crystal display device using the sex conductive sealing material.