JP2003195336A - Liquid crystal display device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To securely prevent a layout line in a gap between substrates outside a seal material from eroding or peeling off from a substrate by covering the layout line with an anticorrosive water-repellent film. <P>SOLUTION: One end part of a flexible wiring board 51 is joined with the top of a projection part 31a of a common-side glass substrate 31 with an anisotropic conductive adhesive 53. Then an organic solvent is atomized and applied to the arrangement part of the layout wire 48 and its vicinity in the gap 55 where both glass substrates 341 and 41 face each other at least at the outside of the seal material 46. Then an anticorrosive water repellent is applied over the area from the gap 55 to the top surface of an end part of the flexible wiring board 51 joined with a common terminal 49 by using an injector before the applied organic solvent vaporizes. Then the presence of the organic solvent decreases the surface viscosity of the anticorrosive water repellent and then the anticorrosive water repellent is securely applied to the inner sides of the gap 55. Therefore, the entire surface of the area up to at least the joint part of the layout wire 48 outside the seal material 46 with the flexible wiring board can securely be covered with a anticorrosive water repellent film 54. In this case, the organic solvent vaporizes and is not left. <P>COPYRIGHT: (C)2003,JPO

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 and a manufacturing method thereof.

[0002]

2. Description of the Related Art FIG. 2 is a partial sectional view of an example of a conventional liquid crystal display device. This liquid crystal display device includes a common side glass substrate 1 arranged on the lower side in FIG.
And a segment side glass substrate 11 arranged on the upper side. On the upper surface of the common-side glass substrate 1 (the surface facing the segment-side glass substrate 11), the black matrix 2 made of a light-shielding metal such as chromium, the red made of a colored resin,
The green and blue color filter elements 3R, 3G, 3B, the flattening film 4 made of acrylic resin, the base film 5 made of silicon oxide, the common electrode 6 made of ITO, and the alignment film 7 made of a polyimide material are in this order. It is provided in.

In this case, the color filter elements 3R, 3
G and 3B are display areas (areas in which a pixel portion described later exists)
It is provided only in. The black matrix 2 is provided in the display area in a grid pattern at the boundary between the color filter elements 3R, 3G, and 3B, and is provided in a rectangular frame shape outside the display area. The black matrix 2, the flattening film 4, and the base film 5 are all provided up to the vicinity of the end face of the common-side glass substrate 1 in order to make the gap uniform. A polarizing plate 8 is attached to a predetermined portion of the lower surface of the common-side glass substrate 1.

On the other hand, a base film 12 made of silicon oxide, a segment electrode 13 made of ITO, and an alignment film 14 made of a polyimide material are formed on the lower surface of the segment side glass substrate 11 (the surface facing the common side glass substrate 1). They are provided in this order. In this case, the base film 12 is provided up to the vicinity of the end face of the segment side glass substrate 11 in order to make the gap uniform. A polarizing plate 15 is attached to a predetermined position on the upper surface of the segment-side glass substrate 11.

The common-side glass substrate 1 and the segment-side glass substrate 11 have a substantially rectangular frame-shaped sealing material 16.
A liquid crystal 17 is sealed in a space surrounded by the sealing material 16 and the two glass substrates 1 and 11 by being bonded together. In this case, the sealing material 16 includes the base film 5 and the base film 12.
Is intervened between.

Here, the common electrode 6 and the segment electrode 1
3 are arranged so as to extend in a direction orthogonal to each other, and the opposing region at the intersection forms a pixel portion. In addition, the segment side glass substrate 1 is provided on one side of the common side glass substrate 1.
A protruding portion 1 a protruding from 1 is formed. On the upper surface of the protruding portion 1a, a common terminal 19 which is conductively connected to the common electrode 6 via a lead wire 18 is provided, and although not shown, the segment electrode 13 is provided on both glass substrates 1 and 11. There are also provided lead wires and segment terminals that are connected by wiring through a cross material that electrically connects these. In this case, the common terminal 19 and its lead wire 18 and the segment terminal and its lead wire are made of ITO.

At the joint portion including the common terminal 19 and the segment terminal on the protruding portion 1a of the common substrate 1, the joint portion including the connection terminal 22 provided on the lower surface of one end of the flexible wiring substrate 21 is anisotropic. It is joined via a conductive adhesive 23. The other end of the flexible wiring board 21 is connected to a circuit board (not shown). Seal material 1
6, the outer surface of the wiring line 18 and the upper surface of the flexible wiring board 21 in the vicinity thereof are covered with the water-repellent film 2 for corrosion prevention.
Covered with 4. The water-repellent film 24 for corrosion prevention is
It is for preventing the wiring line 18 made of O from being corroded by humidity or the like, and is formed by applying a water repellent agent for corrosion prevention by using a syringe.

By the way, in a normal liquid crystal display device, since it is difficult to accurately cut the glass substrate 11 so that the sealing material 16 does not get caught, the error allowance width is provided, and the error allowance width portion is provided. A gap 25 is formed between the glass substrates 1 and 11 outside the sealing material 16. Although the gap 25 is illustrated to be quite large in FIG.
It is an extremely narrow interval slightly larger than about 1 μ).

[0009]

As described above, in the above-mentioned conventional liquid crystal display device, the gap 25 formed between the glass substrates 1 and 12 on the outer side of the sealing material 16 is as narrow as the gap. Even if the water-repellent agent for corrosion prevention is applied using a syringe, it is extremely difficult to apply the water-repellent agent to the back of the gap 25 reliably. Therefore, as shown in FIG.
There has been a problem that the wiring line 18 immediately outside the sealing material 16 cannot be reliably covered with the water-repellent film 24 for corrosion prevention. Since the gap 25 is minute, it is difficult to wipe it off when moisture or the like is accumulated therein, and the portion of the wiring line 18 exposed in the gap 25 is often corroded or peeled off from the glass substrate. An object of the present invention is to provide a liquid crystal display device in which at least a wiring line in a gap between substrates on the outer side of a sealing material is covered with a corrosion-preventing water-repellent film to reliably prevent the corrosion and separation from the substrate, and a manufacturing method thereof. That is.

[0010]

In a liquid crystal display device according to the present invention, as described in claim 1, a pair of substrates provided with electrodes on opposite surfaces are provided with a predetermined gap by a frame-shaped sealing material. Liquid crystal is sealed inside the sealing material in the gap between the pair of substrates, and is electrically connected to the electrode on at least one substrate outside the sealing material of the pair of substrates. A liquid crystal display device in which a wire and an external connection terminal connected to the routing wire are provided, and one end portion of an external wiring substrate is bonded to a bonding portion including the external connection terminal, at least the outside of the sealing material. It is characterized in that the routing wire in the region from the gap to the joint portion is covered with a water-repellent film for corrosion prevention. In this case, as described in claim 2, it is preferable that the external wiring board is a flexible wiring board, and the one end portion of the flexible wiring board to which the flexible wiring board is joined is also covered with the water-repellent film for corrosion prevention. . Further, as described in claim 3, it is preferable that the corrosion-preventing water-repellent film is formed of a fluorine-based organic solvent type paint. According to the method of manufacturing a liquid crystal display device of the present invention, as described in claim 4, a pair of substrates having electrodes on opposite surfaces are bonded to each other with a frame-shaped sealing material to form a predetermined gap. Liquid crystal is enclosed inside the sealing material in the gap between the pair of substrates, and a routing wire conductively connected to the electrode and the routing wire on at least one substrate outside the sealing material of the pair of substrates. A method of manufacturing a liquid crystal display device, wherein external connection terminals connected to each other are provided, and one end portion of an external wiring substrate is bonded to a bonding portion including the external connection terminals, wherein at least a portion where the routing line is disposed in the gap. And after applying an organic solvent to the vicinity thereof, at least the area outside the sealing material from the gap to the joint portion is covered with a corrosion-preventing water-repellent film. It is intended to. in this case,
As described in claim 5, it is preferable that the water-repellent film for corrosion prevention is formed by a fluorine-based organic solvent type coating material. In this case, as described in claim 6, the organic solvent is hydrophobic. It is preferable that the ligroin according to claim 7 is more preferable as the organic solvent having hydrophobicity. Further, according to the present invention, when the corrosion-preventing water repellent is applied after applying the organic solvent, the surface viscosity of the applied corrosion-preventing water repellent is lowered due to the presence of the organic solvent, whereby the sealing material The water repellent for corrosion prevention can be surely applied to the inside of the extremely narrow gap where both substrates face each other on the outer side opposite to the inner side where the liquid crystal is sealed. The entire surface of the region up to the joint with the wiring board can be reliably covered with the corrosion-preventing water-repellent film, and it is possible to sufficiently prevent corrosion of the wiring line due to moisture and peeling from the glass substrate.

[0011]

FIG. 1 is a sectional view of a main part of a liquid crystal display device according to an embodiment of the present invention.
The liquid crystal display device includes a common side glass substrate 31 arranged on the lower side in FIG. 1 and a segment side glass substrate 41 arranged on the upper side. The upper surface of the common side glass substrate 31 (the surface facing the segment side glass substrate 41)
Is a black matrix 32 made of a light-shielding metal such as chromium, red, green, and blue color filter elements 33R, 33G, 33B made of a colored resin, a flattening film 34 made of an acrylic resin, and a base film 35 made of silicon nitride. , ITO
The common electrode 36 formed of and the alignment film 37 formed of a polyimide material are provided.

In this case, the color filter elements 33R, 3R
3G and 33B are provided only in the display area (area in which a pixel portion described later exists). Black matrix 32
Is a color filter element 33R, 33R in the display area.
It is provided in a grid shape at the boundary between G and 33B, and is provided in a rectangular frame shape outside the display area. The black matrix 32, the planarizing film 34, and the base film 35 are all provided up to the vicinity of the end surface of the common-side glass substrate 31 in order to make the gap uniform. A polarizing plate 38 is attached to a predetermined portion of the lower surface of the common-side glass substrate 31.

On the other hand, a base film 42 made of silicon oxide, a segment electrode 43 made of ITO and an alignment film 44 made of a polyimide material are formed on the lower surface of the segment side glass substrate 41 (the surface facing the common side glass substrate 31). It is provided. In this case, the base film 42 is provided up to the vicinity of the end surface of the segment-side glass substrate 41 in order to make the gap uniform. A polarizing plate 45 is attached to a predetermined position on the upper surface of the segment-side glass substrate 41.

The common-side glass substrate 31 and the segment-side glass substrate 41 are substantially rectangular frame-shaped sealing members 4.
A liquid crystal 47 is sealed in a space surrounded by the sealing material 46 and the glass substrates 31 and 41, which are bonded to each other with the liquid crystal 47 interposed therebetween. In this case, the sealing material 46 is interposed between the base films 35 and 42, and conductive patterns such as electrodes and routing lines are formed on the surfaces of the base films 35 and 42, respectively.

Here, the common electrode 36 and the segment electrode 43 are arranged so as to extend in directions orthogonal to each other, and the opposing region at the intersection thereof forms a pixel portion. Further, on one side of the common side glass substrate 31, a protruding portion 31 a protruding from the segment side glass substrate 41 is formed. A common terminal 49, which is conductively connected to the common electrode 36 through a lead wire 48, is provided on the upper surface of the protruding portion 31a. Further, although not shown, the segment electrode 43 is provided.
In addition, there are also provided lead-out wires provided on both glass substrates 1 and 11 and segment terminals which are connected by wiring through a cross material which electrically connects these. In this case, the common terminal 49 and its routing line 48 and the segment terminal and its routing line are made of ITO.

Then, the protrusion 31a of the common-side substrate 31
A joint portion including the connection terminal 52 provided on the lower surface of one end of the flexible wiring board 51 is joined to the joint portion including the upper common terminal 49 and the segment terminal through the anisotropic conductive adhesive 53. The other end of the flexible wiring board 51 is connected to a circuit board (not shown). The entire wiring line 48 outside the sealing material 46 and the upper surface of the flexible wiring substrate 51 in the vicinity thereof are covered with a corrosion-preventing water-repellent film 54. The water-repellent film 54 for corrosion prevention is I
It is for preventing the lead wire 48 made of TO from being corroded by humidity or the like, and is formed by the method described later.

By the way, also in the present embodiment, for the same reason as in the case of the above-mentioned conventional example, a gap 55 is formed between the both glass substrates 31, 41 on the outer side of the sealing material 46. Both glass substrates 31, 41 in this gap 55
Is extremely narrow, which is slightly larger than the cell gap (about 4 to 11 μm). However, in this liquid crystal display device, as described above, at least the flexible wiring substrate 51 of the wiring lines 48 on the outer side of the sealing material 46.
The entire surface of the region up to the junction with the external wiring substrate is covered with the corrosion-preventing water-repellent film 54.

Next, a method of forming the water-repellent film 54 for corrosion prevention will be described. First, the joint portion including the common terminal 49 and the segment terminal on the protruding portion 31 a of the common-side glass substrate 31 is thermocompression-bonded to the joint portion including the connection terminal 52 of the flexible wiring substrate 51 via the anisotropic conductive adhesive 53. By joining.

Next, an organic solvent is applied to at least the gap 55 and its vicinity by a coating method such as spraying. This organic solvent is for reducing the surface viscosity of the water repellent for corrosion prevention which is applied later. The organic solvent used here is preferably one having a strong hydrophobicity in order to take in water and prevent solidification. Further, as the organic solvent, the polarizing plates 38 and 45 and the sealing material 4 are used.
Those having relatively low reactivity such that 6 is not eroded are preferable.

Examples of the organic solvent satisfying the above conditions are ligroin, methanol, ethanol, IPA, methylene chloride, chloroform, carbon tetrachloride, benzene, toluene, o-xylene, m-xylene, p-xylene, acetonitrile and diethyl. Ether, THF, DMF, DM
Examples thereof include SO, ethyl acetate, pentane, n-hexane, cyclohexane, heptane, octane, petroleum ether, and among them, ligroin is more preferable.

When applying the organic solvent, if necessary,
The polarizing plates 38 and 45 may be masked. Then, when the organic solvent is applied, depending on the degree of volatility of the organic solvent, that is, before the applied organic solvent evaporates, the upper surface of the end portion of the flexible wiring substrate 51 joined to the common terminal 49 or the like through the gap 55. A corrosion-repellent water repellent is applied over the entire area using a syringe. Then,
Due to the presence of the organic solvent, the surface viscosity of the corrosion-preventing water repellent applied is reduced, whereby the narrow gap 55 formed between the glass substrates 31 and 41 on the outer side of the sealing material 46.
The water repellent for corrosion prevention is surely applied to the inside of the.

Therefore, the corrosion-preventing water-repellent film 5 is formed on the entire surface of the area outside the sealing material 46 up to at least the joint with the flexible wiring board of the wiring line 48.
It can be surely covered with No. 4, and it is possible to sufficiently prevent the wiring line from being corroded and peeling from the glass substrate due to moisture. Here, the water repellent for corrosion prevention has water repellency and repels water, and a fluorine-based organic solvent type paint or the like is suitable. The organic solvent volatilizes and does not remain.

[0023]

As described above, according to the present invention, when the water repellent for corrosion prevention is applied after the organic solvent is applied, the surface viscosity of the water repellent for corrosion prevention applied due to the presence of the organic solvent. As a result, the water repellent for corrosion prevention can be surely applied to the inside of the extremely narrow gap where both substrates face each other on the outer side opposite to the inner side where the liquid crystal of the sealing material is sealed. The entire surface of the routing wire on the outside of the material up to at least the joint with the external wiring board can be reliably covered with a water-repellent film for corrosion prevention, and the routing wire is corroded by moisture and peeled from the glass substrate. Can be sufficiently prevented.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a liquid crystal display device as an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of an example of a conventional liquid crystal display device.

[Explanation of symbols]

31 Common side glass substrate 36 common electrode 38 Polarizer 41 segment side glass substrate 43 segment electrodes 45 Polarizer 46 Seal material 47 LCD 48 routing line 49 common terminal 51 Flexible wiring board 53 Anisotropic conductive adhesive 54 Water-repellent film for corrosion prevention 55 Gap

Front page continued (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05K 3/28 H05K 3/28 BF term (reference) 2H092 GA32 GA50 HA04 HA12 HA18 HA24 HA28 MA10 NA17 PA04 5C094 AA32 AA43 BA43 CA14 CA24 DA07 DA12 DA15 DB03 DB05 EA07 EB02 FA01 FB01 FB15 5E314 AA39 BB06 BB11 CC01 FF06 GG01 GG11 5E344 AA02 BB02 BB04 DD06 DD10 5G435 AA13 AA14 AA17 BB12 EE32 EE42 EE47 HH20 KK05

Claims (7)

[Claims] 1. A pair of substrates having electrodes provided on opposite surfaces thereof are bonded together by forming a predetermined gap by a frame-shaped sealing material, and a liquid crystal is provided inside the sealing material in the gap between the pair of substrates. Is provided, a lead wire conductively connected to the electrode and an external connection terminal connected to the lead wire are provided on at least one substrate outside the sealing material of the pair of substrates, and the external connection terminal is connected to the lead wire. A liquid crystal display device in which one end portion of an external wiring board is joined to a joint portion including the outer wiring substrate, wherein the routing line at least in an area extending from the gap to the joint portion outside the sealing material is covered with a water-repellent film for corrosion prevention. A liquid crystal display device characterized in that 2. The invention according to claim 1, wherein the external wiring board is a flexible wiring board, and the one end of the flexible wiring board joined to the flexible wiring board is also covered with the corrosion-preventing water-repellent film. Liquid crystal display device characterized by. 3. The liquid crystal display device according to claim 1, wherein the water-repellent film for corrosion prevention is formed of a fluorine-based organic solvent type paint. 4. A pair of substrates having electrodes provided on opposite surfaces thereof are bonded together by forming a predetermined gap by a frame-shaped sealing material, and a liquid crystal is provided inside the sealing material in the gap between the pair of substrates. Is provided, a lead wire conductively connected to the electrode and an external connection terminal connected to the lead wire are provided on at least one substrate outside the sealing material of the pair of substrates, and the external connection terminal is connected to the lead wire. A method of manufacturing a liquid crystal display device, wherein one end of an external wiring substrate is bonded to a bonding portion including the sealing material, after applying an organic solvent to at least the portion where the routing line is disposed in the gap and its vicinity. A method for manufacturing a liquid crystal display device, characterized in that at least the wiring line on the outer side from the gap to the joint portion is covered with a water-repellent film for corrosion prevention. 5. The method of manufacturing a liquid crystal display device according to claim 4, wherein the water-repellent film for corrosion prevention is formed of a fluorine-based organic solvent type paint. 6. The method of manufacturing a liquid crystal display device according to claim 4 or 5, wherein the organic solvent has a hydrophobic property. 7. The method of manufacturing a liquid crystal display device according to claim 6, wherein the organic solvent is ligroin.