JPH0980459A - Liquid crystal display - Google Patents

Abstract

(57) Abstract: A liquid crystal display panel can be downsized, cost can be reduced, and assembling workability can be improved. A flexible wiring board 21a is adhered to a hard circuit board 31a via an adhesive 42a, so that the flexible wiring board 21a is easier to handle than a case where the flexible wiring board 21a is used alone.
Assembly workability can be improved. Further, since the semiconductor chip 41a is wire (45a, 46a) bonded to the circuit board 31a and the flexible wiring board 21a, the liquid crystal display panel 1 is different from the case of COG mounting.
1 can be miniaturized, and the cost can be reduced as compared with the case of TAB mounting. Furthermore, since the flexible wiring board 21a has a single-sided wiring structure,
The cost can be reduced as compared with the case of the double-sided wiring structure.

Description

Detailed Description of the Invention

[0001]

[0001] The present invention relates to a liquid crystal display device.

[0002]

2. Description of the Related Art A liquid crystal display device is generally a liquid crystal display panel in which liquid crystal is sealed between two transparent substrates made of glass or the like, and ICs and LS for driving the liquid crystal display panel.
A semiconductor chip made of I or the like, a circuit board for supplying a display signal to the semiconductor chip, and the like are provided. There are several types of such liquid crystal display devices due to the difference in modularization. Next, three representative types will be described.

First, as shown in FIG. 8, a semiconductor chip 1 is mounted on a TAB (Tape Automated Bonding) tape 2 (TAB mounting), and a liquid crystal display panel 3 and a hard circuit board 4 are mounted on the TAB tape 2. There is something connected through. Secondly, as shown in FIG. 9, the semiconductor chip 1 is mounted on the liquid crystal display panel 3 (COG (Chip On Grass) mounting), and the liquid crystal display panel 3 and the hard circuit board 4 are connected via the flexible wiring board 5. There is something connected. Third, FIG.
As shown in FIG. 1, there is a semiconductor device in which the semiconductor chip 1 is mounted on a flexible wiring board 5 (COF (Chip On Film) mounting), and the liquid crystal display panel 3 and the hard circuit board 4 are connected via the flexible wiring board 5. .

[0004]

However, in the case of the TAB-mounted liquid crystal display device shown in FIG. 8, there is a problem that the cost increases due to the complicated manufacturing process of the TAB tape 2. In the case of the COG-mounted liquid crystal display device shown in FIG. 9, since the semiconductor chip 1 is mounted on the liquid crystal display panel 3, the liquid crystal display panel 3 becomes large, and display signals from the circuit board 4 are transmitted to a plurality of semiconductor chips. The flexible wiring board 5 has to have a double-sided wiring structure because of the supply in parallel with 1, and there is a problem that the cost becomes high. In the case of the COF-mounted liquid crystal display device shown in FIG. 10, the semiconductor chip 1 is connected to the flexible wiring board 5.
In the step of mounting the flexible wiring board 5 on which the semiconductor chip 1 is mounted and the step of connecting the liquid crystal display panel 3 with the semiconductor chip 1 mounted thereon, it is very difficult to handle the flexible wiring board 5, and as a result, the assembly work becomes troublesome.
Similar to the case of OG mounting, the flexible wiring board 5 must have a double-sided wiring structure, which causes a problem of high cost. An object of the present invention is to reduce the size of a liquid crystal display panel, reduce the cost, and improve the assembling workability.

[0005]

According to the first aspect of the present invention,
A liquid crystal display panel, a wiring formed on only one surface, one end of the one surface is connected to the liquid crystal display panel, a flexible wiring substrate, and a semiconductor chip for driving the liquid crystal display panel, And a circuit board for supplying a display signal to the semiconductor chip, an opening is formed in the flexible wiring board, and the other surface of the flexible wiring board is formed on the other side of the circuit board. Bonding to one surface, the semiconductor chip is placed in the opening,
Moreover, the input terminal of the semiconductor chip is wire-bonded to the wiring on the one surface of the circuit board, and the output terminal of the semiconductor chip is wire-bonded to the wiring on the one surface of the flexible wiring board. The invention according to claim 2 drives the liquid crystal display panel, a liquid crystal display panel, a flexible wiring board in which wiring is formed only on one surface, and one end of the one surface is connected to the liquid crystal display panel. And a circuit board for supplying a display signal to the semiconductor chip, wherein a wiring is formed on one surface, and an opening is formed in the flexible wiring board. The other surface is adhered to one surface of the circuit board, the semiconductor chip is arranged on the one surface of the flexible wiring board in the vicinity of the opening, and the input terminal of the semiconductor chip is connected to the opening. Wire bonding to the wiring on the one surface of the circuit board through the wire, and the output terminal of the semiconductor chip to the wiring on the one surface of the flexible wiring board. Than it is. The invention according to claim 6 comprises a liquid crystal display panel, a semiconductor chip for driving the liquid crystal display panel, and a wiring board for supplying a display signal to the semiconductor chip, and an end of the liquid crystal display panel. Section and the end portion of the wiring board are arranged along each other, and the input terminal of the semiconductor chip is connected to the wiring provided on one surface of the wiring board in the portion along the line and the liquid crystal display panel in the portion along the line. The output terminal of the semiconductor chip is connected to the wiring provided on the first surface.

According to the invention of claim 1 or 2, since the other surface of the flexible wiring board is adhered to the one surface of the circuit board, in this state, that is, the flexible wiring board is reinforced by the circuit board. If the semiconductor chip bonding step and the connecting step of the flexible wiring board and the liquid crystal display panel are performed in, the flexible wiring board can be handled more easily than in the case of the flexible wiring board alone, and therefore, the assembling workability can be improved. . Further, since the input terminal of the semiconductor chip is wire-bonded to the wiring on the one surface of the circuit board and the output terminal of the semiconductor chip is wire-bonded to the wiring on the one surface of the flexible wiring board, the semiconductor chip is connected to the circuit board. Further, the liquid crystal display panel can be downsized as compared with the case of COG mounting, and the cost can be reduced as compared with the case of TAB mounting, since it can be bonded directly to the flexible wiring board. Furthermore, the wiring may be provided only on one surface of the flexible wiring board,
Therefore, the cost can be reduced as compared with the case of the double-sided wiring structure. According to the invention of claim 6, the end of the liquid crystal display panel and the end of the wiring board are aligned with each other,
The input terminal of the semiconductor chip is connected to the wiring provided on the one surface of the wiring board in the portion along the line, and the output terminal of the semiconductor chip is connected to the wiring provided on the one surface of the liquid crystal display panel in the portion along the line. Since it does, C
The liquid crystal display panel can be downsized as compared with the case of OG mounting, and the cost can be reduced as compared with the case of TAB mounting. In this case, if the wiring is provided only on one surface of the flexible wiring board as in the invention described in claim 8, the cost can be reduced as compared with the case of the double-sided wiring structure.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a main part of a liquid crystal display device according to a first embodiment of the present invention. This liquid crystal display device includes a liquid crystal display panel 11. The liquid crystal display panel 11 is formed by enclosing a liquid crystal (not shown) between an upper transparent substrate 12 and a lower transparent substrate 13 made of glass or the like. In this case, a predetermined side of the upper transparent substrate 12 is projected from the lower transparent substrate 13, and the connecting terminal 14a (see FIG. 2) is provided on the lower surface of this projecting portion.
Further, two predetermined sides of the lower transparent substrate 13 are projected from the upper transparent substrate 12, and the connection terminals 14b are provided on the upper surfaces of these projected portions.
(See FIG. 3) are provided.

Flexible wiring boards 21a and 21b, circuit boards 31a and 31b, semiconductor chips 41a and 41b, etc. are arranged in the vicinity of the protruding portions of the upper transparent substrate 12 and the lower transparent substrate 13, respectively. First, the vicinity of the protruding portion of the upper transparent substrate 12 will be described with reference to FIG. The upper surface of one end in the width direction of the strip-shaped flexible wiring board 21a is connected to the lower surface of the protruding portion of the upper transparent substrate 12 via the anisotropic conductive adhesive 22a. An opening 23a is provided at a predetermined location of the flexible wiring board 21a, and an input terminal 24a, an output terminal 25a and a lead wire 26a therebetween are provided at each predetermined location on the upper surface of the flexible wiring board 21a. The output terminal 25a includes an anisotropic conductive adhesive 22a on the connection terminal 14a of the upper transparent substrate 12.
Connected through.

The upper surface of the hard circuit board 31a is adhered to the lower surface of the flexible wiring board 21a with an adhesive 32a. Opening 2 of flexible wiring board 21a
A connection terminal 33a is provided at a predetermined position on the upper surface of the circuit board 31a in the portion corresponding to 3a.

The opening 23 of the flexible wiring board 21a
A semiconductor chip 41a is arranged at a predetermined position on the upper surface of the circuit board 31a in a by being bonded with an adhesive 42a. An input terminal 43a and an output terminal 44a are provided at predetermined locations around the upper surface of the semiconductor chip 41a. The input terminal 43a is wire-bonded to the connection terminal 33a of the circuit board 31a via the wire 45a. The output terminal 44a is wire-bonded to the input terminal 24a of the flexible wiring board 21a via the wire 46a. The semiconductor chip 41a and the wires 45a and 46a are sealed with a resin sealant 47a made of epoxy resin or the like.

Next, the vicinity of the protruding portion of the lower transparent substrate 13 will be described with reference to FIG. A strip-shaped flexible wiring board 21b is provided on the upper surface of the protruding portion of the lower circuit board 13.
The lower surface of the one end in the width direction is connected via the anisotropic conductive adhesive 22b. The flexible wiring board 21b is provided with an opening portion 23b at a predetermined position, and the lower surface thereof is provided with an input terminal 24b, an output terminal 25b and a lead wire 26b therebetween. Output terminal 2
5b is connected to the connection terminal 14b of the lower circuit board 13 via the anisotropic conductive adhesive 22b.

The lower surface of the hard circuit board 31b is adhered to the upper surface of the flexible wiring board 21b via an adhesive 32b. Opening 2 of flexible wiring board 21b
A connection terminal 33b is provided at a predetermined position on the lower surface of the circuit board 31b in a portion corresponding to 3b.

Opening 23 of flexible wiring board 21b
A semiconductor chip 41b is arranged in a predetermined position on the lower surface of the circuit board 31b in b by being bonded via an adhesive 42b. An input terminal 43b and an output terminal 44b are provided at predetermined locations around the lower surface of the semiconductor chip 41b. The input terminal 43b is wire-bonded to the connection terminal 33b of the circuit board 31b via the wire 45b. The output terminal 44b is wire-bonded to the input terminal 24b of the flexible wiring board 21b via the wire 46b. The semiconductor chip 41b and the wires 45b and 46b are sealed with a resin sealant 47b made of epoxy resin or the like.

Then, as shown in FIG. 1, the lower transparent substrate 1
A predetermined portion of the lower surface of the flexible wiring board 21b arranged near the protruding portion of No. 3 is anisotropically conductively bonded to a predetermined portion of the upper surface of the circuit board 31a arranged near the protruding portion of the upper transparent substrate 12. It is connected via an agent (not shown).

Next, in the case of assembling this liquid crystal display device, as a representative, the vicinity of the protruding portion of the upper transparent substrate 12 will be described with reference to FIG. First,
The semiconductor chip 41 is provided at a predetermined position on the upper surface of the circuit board 31a.
a is adhered and arranged via the adhesive 42a. Next, the lower surface of the flexible wiring board 21b is bonded to the upper surface of the circuit board 31a with the adhesive 32a so that the semiconductor chip 41a is positioned in the opening 23b of the flexible wiring board 21b.
Glue through. Next, by wire bonding,
The input terminal 43a of the semiconductor chip 41a is connected to the circuit board 31a.
The connection terminals 33a on the upper surface of the semiconductor chip 41a are connected via the wires 45a, and the output terminals 44a of the semiconductor chip 41a are connected to the input terminals 24a on the upper surface of the flexible wiring board 21a via the wires 46a. Next, the semiconductor chip 41
a and wires 45a, 46a are covered with a resin sealant 47
Seal with a. Next, by thermocompression bonding, the connection portion including the output terminal 25a of the flexible wiring board 21a is connected to the connection portion including the connection terminal 14a of the upper transparent substrate 12 via the anisotropic conductive adhesive 22a. Thus, the vicinity of the protruding portion of the upper transparent substrate 12 is assembled.

Thus, when assembling the vicinity of the protruding portion of the upper transparent substrate 12, the lower surface of the flexible wiring board 21a is adhered to the upper surface of the circuit board 31a via the adhesive 42a, and in this state, that is, the flexible wiring board. 21a is a semiconductor chip (41a) with the circuit board 31a reinforced.
Since the bonding step and the connecting step between the flexible wiring board 21a and the liquid crystal display panel 11 are performed, the flexible wiring board 21a is easier to handle than the case where the flexible wiring board is used alone, and therefore, the assembling workability is improved. You can Further, the input terminal 43a of the semiconductor chip 41a is wire (45a) bonded to the connection terminal 33a on the upper surface of the circuit board 31a, and the output terminal 44a of the semiconductor chip 41a is wire (4) to the input terminal 24a on the upper surface of the flexible wiring board 21a.
6a) Since it is bonded, the semiconductor chip 41a
Need only be directly bonded to the circuit board 31a and the flexible wiring board 21a, so that the liquid crystal display panel 11 can be downsized as compared with the case of COG mounting, and the cost can be reduced as compared with the case of TAB mounting. be able to. Furthermore, the flexible wiring board 21a
The wiring consisting of the input terminal 24a, the output terminal 25a and the leading wire 26a between them may be provided only on the upper surface of
Therefore, the cost can be reduced as compared with the case of the double-sided wiring structure.

Next, FIG. 4 is a sectional view similar to FIG. 2 of a liquid crystal display device according to a second embodiment of the present invention. In this embodiment, an opening 23a is formed in a predetermined portion of the flexible wiring board 21a, and a lower surface of the flexible wiring board 21a is attached to an upper surface of the circuit board 31a by an adhesive 32.
a, and the semiconductor chip 41a is arranged on the upper surface of the flexible wiring board 21a near the opening 23a with an adhesive 42a. Then, the input terminal 43a of the semiconductor chip 41a is connected to the opening 23a. To the connection terminal 33a on the upper surface of the circuit board 31a through the wire (45a)
In addition to bonding, the output terminal 44a of the semiconductor chip 41a is wire (46a) bonded to the input terminal 24a on the upper surface of the flexible wiring board 21a, and then the semiconductor chip 41a and the wires 45a, 46a are sealed with a resin sealant 47a. It was done. In this case, the semiconductor chip 41a is connected to the flexible wiring board 21.
Since it is mounted on a, more wiring can be formed on the upper surface of the circuit board 31a as compared with the case of the first embodiment. As a result, the circuit board 31a can have a single-sided wiring structure.

Next, FIG. 5 is a sectional view similar to FIG. 2 of the liquid crystal display device according to the third embodiment of the present invention, and FIG. 6 is a view of the liquid crystal display device according to the fourth embodiment of the present invention. 2 is a sectional view similar to FIG. In these embodiments, the wiring 27a that is a part of the wiring between the plurality of (three or four in the case of FIG. 1) semiconductor chips 41a is formed at a predetermined position on the upper surface of the flexible wiring board 21a. , The input terminal 43a of the semiconductor chip 41a
Is partially bonded to the wiring 27a by a wire (48a). In this case, as many wirings as the wirings 27a formed on the flexible wiring board 21a can be formed on the upper surface of the circuit board 31a. As a result, the circuit board 31a can have a single-sided wiring structure. Particularly, in the case of the fourth embodiment shown in FIG. 6, the circuit board 31a can be made to have a single-sided wiring structure.

In the above embodiment, the circuit board 31
Although the case where a hard substrate is used as a and 31b has been described, a flexible substrate may be used.
In this case, if necessary, the circuit boards 31a and 31b, which are flexible boards, and the flexible wiring board 21a,
The reinforcing plate may be attached to the adhesive 21b.

Next, FIG. 7 is a plan view of a main portion of a liquid crystal display device according to a fifth embodiment of the present invention.
In this embodiment, the liquid crystal display panel 51 has a structure in which two adjacent predetermined sides of the lower transparent substrate 52 are projected from the upper transparent substrate 53, and the output wiring 54 is formed on the upper surfaces of these projected portions. . The flexible wiring board 55 includes a first wiring board portion 55a arranged along one protruding portion of the lower transparent substrate 52 and a second wiring board arranged along another protruding portion of the lower transparent substrate 52. Part 55b,
The third wiring board portion 55c connected to a hard circuit board (not shown) is provided, and the input wiring 56 is formed only on the upper surface of these wiring board portions.

The upper surface of one protruding portion of the lower transparent substrate 52 and the first wiring board portion 55a arranged along this protruding portion, and the other protruding portion of the lower transparent substrate 52 and this protruding portion. An anisotropic conductive adhesive (a mixture of electrically conductive particles in an insulating adhesive) 57 is arranged on the upper surface of the second wiring board portion 55b which is arranged in parallel. A semiconductor chip 58 is provided on the upper surface of the agent 57.
Is arranged. That is, the semiconductor chip 58 has its input terminal (not shown) connected to the input wiring 56 of the flexible wiring board 55 via the anisotropic conductive adhesive 57, and its output terminal (not shown). In a state of being connected to the output wiring 54 of the lower transparent substrate 52 via the anisotropic conductive adhesive 57, the protruding portion of the lower transparent substrate 52 and the flexible wiring board portion 55 arranged along the protruding portion are arranged. It is located on the top surface.

As described above, in this embodiment, the protruding portion (end portion) of the lower transparent substrate 52 of the liquid crystal display panel 51 and the end portion of the flexible wiring substrate 55 are arranged along each other, and the flexible wiring substrate 55 in this portion is arranged. The input terminal of the semiconductor chip 58 is connected to the input wiring 56 provided on the upper surface of the liquid crystal display panel 51 through the anisotropic conductive adhesive 57, and is provided on the upper surface of the lower transparent substrate 52 of the liquid crystal display panel 51 in the portion along the above. Since the output terminal of the semiconductor chip 58 is connected to the output wiring 56 via the anisotropic conductive adhesive 57, the liquid crystal display panel can be downsized as compared with the case of COG mounting, and the TAB mounting can be achieved. The cost can be reduced as compared with the case. Further, the input wiring 56 may be provided only on the upper surface of the flexible wiring board 55, so that the cost can be reduced as compared with the case of the double-sided wiring structure. The flexible wiring board 55 is omitted, and a hard circuit board is arranged along the liquid crystal display panel, and a semiconductor chip is placed on the upper surface of the circuit board and the liquid crystal display panel along this portion via an anisotropic conductive adhesive. It may be arranged. Also, the anisotropic conductive adhesive 5
Instead of 7, a zebra type one in which conductive layers and insulating layers made of silver paste or the like are alternately arranged may be used.

[0023]

As described above, claim 1 or 2
According to the invention described above, since the other surface of the flexible wiring board is adhered to the one surface of the circuit board, in this state, that is, in the state where the flexible wiring board is reinforced by the circuit board, the semiconductor chip bonding process and the flexible wiring are performed. When the step of connecting the substrate and the liquid crystal display panel is performed, the flexible wiring board can be handled more easily than in the case where the flexible wiring board is used alone, and therefore the assembling workability can be improved. Further, since the input terminal of the semiconductor chip is wire-bonded to the wiring on the one surface of the circuit board and the output terminal of the semiconductor chip is wire-bonded to the wiring on the one surface of the flexible wiring board, the semiconductor chip is connected to the circuit board. Further, the liquid crystal display panel can be downsized as compared with the case of COG mounting, and the cost can be reduced as compared with the case of TAB mounting, since it can be bonded directly to the flexible wiring board. Further, the wiring may be provided only on one surface of the flexible wiring board, so that the cost can be reduced as compared with the case of the double-sided wiring structure. According to the invention of claim 6, the end portion of the liquid crystal display panel and the end portion of the wiring board are aligned with each other, and the semiconductor chip is input to the wiring provided on the one surface of the wiring board in the portion along this side. Since the terminals are connected and the output terminal of the semiconductor chip is connected to the wiring provided on the one surface of the liquid crystal display panel in the above-mentioned portion, the liquid crystal display panel can be downsized as compared with the case of COG mounting. In addition, the cost can be reduced as compared with the case of TAB mounting. In this case, if the wiring is provided only on one surface of the flexible wiring board as in the invention described in claim 8, the cost can be reduced as compared with the case of the double-sided wiring structure.

[Brief description of drawings]

FIG. 1 is a plan view of a main part of a liquid crystal display device according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line XX in FIG.

3 is a cross-sectional view taken along the line YY of FIG.

FIG. 4 is a sectional view of the liquid crystal display device according to the second embodiment of the present invention, similar to FIG.

FIG. 5 is a sectional view similar to FIG. 2 of the liquid crystal display device according to the third embodiment of the present invention.

FIG. 6 is a sectional view similar to FIG. 2 of a liquid crystal display device according to a fourth embodiment of the present invention.

FIG. 7 is a plan view of a main part of a liquid crystal display device according to a fifth embodiment of the present invention.

FIG. 8 is a plan view showing a first example of a conventional liquid crystal display device.

FIG. 9 is a plan view showing a second example of a conventional liquid crystal display device.

FIG. 10 is a plan view showing a third example of a conventional liquid crystal display device.

[Explanation of symbols]

 11 Liquid Crystal Display Panels 21a, 21b Flexible Wiring Boards 23a, 23b Openings 31a, 31b Circuit Boards 41a, 41b Semiconductor Chips

Claims (10)

[Claims] 1. A liquid crystal display panel, a wiring formed only on one surface, and a flexible wiring substrate having one end of the one surface connected to the liquid crystal display panel, and a liquid crystal display panel for driving the liquid crystal display panel. A semiconductor chip; and a circuit board for supplying a display signal to the semiconductor chip, wherein a wiring is formed on one surface, an opening is formed in the flexible wiring board, and the other surface of the flexible wiring board is provided. Is bonded to one surface of the circuit board, the semiconductor chip is arranged in the opening, and the input terminal of the semiconductor chip is wire-bonded to the wiring on the one surface of the circuit board, and A liquid crystal display device, wherein an output terminal is wire-bonded to a wiring on one surface of the flexible wiring board. 2. A liquid crystal display panel, a wiring formed only on one surface, and a flexible wiring substrate having one end of the one surface connected to the liquid crystal display panel, and a liquid crystal display panel for driving the liquid crystal display panel. A semiconductor chip; and a circuit board for supplying a display signal to the semiconductor chip, wherein a wiring is formed on one surface, an opening is formed in the flexible wiring board, and the other surface of the flexible wiring board is provided. Is bonded to one surface of the circuit board, the semiconductor chip is arranged on the one surface of the flexible wiring board in the vicinity of the opening, and the input terminal of the semiconductor chip is inserted through the opening. While wire bonding to the wiring on one surface of the circuit board,
A liquid crystal display device, wherein output terminals of the semiconductor chip are wire-bonded to wiring on one surface of the flexible wiring board. 3. The method according to claim 1, wherein
A liquid crystal display device comprising a plurality of semiconductor chips, and a part of wiring between the semiconductor chips is formed on one surface of the flexible wiring board. 4. The liquid crystal display device according to claim 1, wherein the semiconductor chip portion is sealed with a resin sealing material. 5. The liquid crystal display device according to any one of claims 1 to 4, wherein the circuit board is a hard board. 6. A liquid crystal display panel, a semiconductor chip for driving the liquid crystal display panel, and a wiring board for supplying a display signal to the semiconductor chip, the end portion of the liquid crystal display panel, and the wiring board for supplying a display signal to the semiconductor chip. The input terminal of the semiconductor chip is connected to the wiring provided on the one surface of the wiring board in the portion along the end portion of the wiring board, and the one end of the liquid crystal display panel in the portion along the wiring board is connected. A liquid crystal display device, wherein an output terminal of the semiconductor chip is connected to a wiring provided on the surface. 7. A liquid crystal display panel, a semiconductor chip for driving the liquid crystal display panel, and a wiring board for supplying a display signal to the semiconductor chip, the end portion of the liquid crystal display panel and the wiring board for supplying a display signal to the semiconductor chip. The end portions of the wiring board are aligned with each other, and the anisotropic conductive adhesive is arranged on one surface of the portion along the wiring board, and the semiconductor chip is attached to the wiring provided on the one surface of the wiring board at the portion along the wiring board. The input terminals are connected via the anisotropic conductive adhesive, and the output terminals of the semiconductor chip are connected to the wiring provided on the one surface of the liquid crystal display panel in the portion along the anisotropic conductive adhesive. A liquid crystal display device characterized by being connected through. 8. The invention according to claim 6 or 7,
The liquid crystal display device, wherein the wiring board is a flexible wiring board. 9. The liquid crystal display device according to claim 8, wherein wiring is formed only on one surface of the flexible wiring board. 10. The liquid crystal display device according to claim 6, wherein the wiring board is a hard circuit board.