JP3140163B2 - Liquid crystal display - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a smaller liquid crystal display device.

[0002]

2. Description of the Related Art FIGS. 7 and 8 show a liquid crystal display device which has been already proposed. First, in a liquid crystal display device 1 shown in FIG. 7, a display area 3 provided with a liquid crystal layer is provided on a main surface of a glass substrate 2. FIG. In addition to the display area 3, a plurality of ICs 4 for inputting signals to the display area 3 are arranged, and a wiring board 5 such as an FPC for inputting signals is connected to one end of the glass substrate 2. The IC 4 and the wiring substrate 5 are connected by a wiring pattern 6 formed around the glass substrate 2 and made of aluminum or the like.

In the liquid crystal display device 7 shown in FIG. 8, a plurality of ICs 10 for inputting signals to the display region 9 are arranged in addition to the display region 9 provided on the main surface of the glass substrate 8. A wiring board 11 such as an FPC for inputting a signal is connected along one side of the glass substrate 8, and these ICs 10 and the wiring board 11 are very close to each other. Is a small area.

[0004]

First, in the liquid crystal display device 1 shown in FIG. 7, an area for forming the wiring pattern 6 is required on one main surface of the glass substrate 2, and thus the dimensions of the liquid crystal display device 1 itself are reduced. Have become larger and have not been able to meet the recent demand for miniaturization.

Further, according to the liquid crystal display device 7 having the configuration shown in FIG. 8, the area for forming the wiring pattern is narrower than that of the liquid crystal display device 1.
When the liquid crystal display device 7 is mounted on a housing (not shown), the liquid crystal display device 7 is bent along a fold line 13, but since the wiring substrate 11 is elastic, it must be used with a tape or the like for fixing. Therefore, there is a problem that workability is poor.

[0006]

According to the liquid crystal display device of the present invention, a liquid crystal is sealed between two opposing glass substrates to form a display region, and electrodes are arranged on the inner surface of each glass substrate in the display region. And a configuration in which the electrode is connected to a signal input wiring provided in an area other than the display area of the substrate, wherein the signal input wiring is a long layer formed by alternately stacking wiring layers and ceramic substrates. It is characterized in that it is constituted by a multi-layered multilayer wiring board and is arranged along the end face of one of the glass substrates.

[0007]

The present invention will be described below with reference to examples.

FIG. 1 shows a liquid crystal display device 1 according to an embodiment of the present invention.
FIG. 4 is a perspective view showing a partial cross section, FIG. 2 is a plan view of the liquid crystal display device 14, and FIG. 3 is a cross sectional view taken along the line XX of FIG.

The liquid crystal display device 14 includes a pair of glass substrates 15 and 16 and is formed on each of the glass substrates 15 and 16 in a strip shape with ITO (indium tin oxide) so as to extend in a direction perpendicular to each other. Transparent electrodes 17, 18
Are formed, thereby forming the display area 19.
Further, alignment films 20 and 21 are provided on each of the glass substrates 15 and 16, and a liquid crystal 22 is interposed between the alignment films 20 and 21. It is sealed with the material 23.

The transparent electrode 17 on the glass substrate 15 is formed to extend to the exposed wiring regions 24 and 25 extending outward from the glass substrate 16 of the glass substrate 15,
Is configured as These connection wirings 26 are connected to a plurality of drive circuit elements 27. On the other hand, the transparent electrode 18 on the glass substrate 16 is individually connected to a connection wiring 28 formed on the glass substrate 15 corresponding to the transparent electrode 18, and this connection is made of, for example, silver paste or anisotropic conductive material. This is performed using The connection wiring 28 is connected to a plurality of drive circuit elements 29 on the glass substrate 15.

Reference numeral 30 denotes a flexible wiring board, and various control signals or display data are input from the outside to the respective drive circuit elements 27 and 29 via the flexible wiring board 30. One terminal of each of the drive circuit elements 27 and 29 is wire-bonded 31 to the connection wires 26 and 28 and a gold wire, and the other terminal is wire-bonded 33 to a wire 32 used for signal input.

On the wiring 32, there is provided a multilayer ceramic substrate 34 which constitutes a multilayer wiring board in which wiring portions and insulating portions are alternately laminated. FIG. 4 is an exploded perspective view of the laminated ceramic substrate 34, which has a laminated structure of, for example, three ceramic substrates 35, 36, and 37. These substrates 35, 36, and 37 include, for example, copper, aluminum, chromium aluminum A wiring 38 is formed by patterning by etching a material formed by vapor deposition of these materials or a material obtained by bonding foils of these materials, and the wiring 38 on each of the ceramic substrates 35, 36, and 37 is It is electrically conducted through a through hole 39 indicated by a black dot.

The lowermost ceramic substrate 35
The through hole 39 exposed on the outer surface of the conductive adhesive 4
The conductive adhesive 40 is electrically connected to the wiring 32 through the line 0, for example, a thermosetting anisolum containing conductive particles.

When the laminated ceramic substrate 34 is used as described above, the thermal expansion coefficient of the ceramic substrate is similar to the thermal expansion coefficients of the glass substrates 15 and 16, and
This is advantageous in that it is suitable for a rapid heating process performed in an inspection process after the completion of the liquid crystal display device 14. In this heating process, generally, in the region of the liquid crystal 22 sandwiched between the two glass substrates 15 and 16, the pressure is set lower than the atmospheric pressure.
5 and 16 are prevented from swelling. However, if such a negative pressure is too large, air bubbles may be generated at a low temperature. Therefore, if the coefficient of thermal expansion of the laminated ceramic substrate 34 and the coefficient of thermal expansion of the glass substrates 15 and 16 are close to each other during the heating process, the glass substrates 15 and 16 will not be broken.

Further, dividing the laminated ceramic substrate 34 into a plurality of parts in the longitudinal direction thereof is advantageous in that the above-mentioned adverse effect due to the coefficient of thermal expansion can be reduced.

Further, in the above-described structure, a relatively flexible and chemically stable synthetic resin one layer 41 such as a silicon resin is filled between the laminated ceramic substrate 34 and the glass substrate 16. , Each of the drive circuit elements 27 and 29 is covered, whereby the wire bonding 31, 33
In addition, the drive circuit elements 27 and 29 are protected.

Further, the cover body 42 having a substantially L-shaped cross section is fixed by aligning the heights of the outer surfaces of the multilayer ceramic substrate 34 and the glass substrate 16. This cover body 4
Numeral 2 is made of a metal such as iron, aluminum, stainless steel or the like, and resiliently presses the pair of glass substrates 15, 16 or the laminated ceramic substrate 34 and the glass substrate 15 by its own spring force.

Thus, according to the liquid crystal display device 14 having the above configuration, each of the drive circuit elements 27,
A part of the input wiring pattern reaching 29 becomes three-dimensional, and accordingly, the wiring area becomes smaller as compared with the two-dimensionally wired space, and the bonding area of the multilayer ceramic substrate 34 becomes smaller. The dimensions of the liquid crystal display device 14 itself have been reduced. Further, the height of the laminated ceramic substrate 34 is aligned with the glass substrate 16 so that the cover 42
Was provided to protect the wire bondings 31 and 33 and the drive circuit elements 27 and 29.

When the present inventors conducted experiments using a 1024 × 760 dot 10-inch class liquid crystal display device, the liquid crystal display device of FIG. 7 required a dead space of 3.5 cm in width. In this embodiment, the width can be reduced to 2 cm or less.

[0020]

The present invention may be modified as follows in addition to the above embodiment.

The liquid crystal display device 1 of the embodiment shown in FIGS.
4, the driving circuit elements 27, 2
In this example, the flexible wiring board 30 is provided on the center line of both arrangements. However, as shown in FIG. The substrate 30 may be bonded by solder. still,
In the figure, the portions denoted by the same reference numerals have the same functions.

In FIG. 5, a multilayer ceramic substrate 34
Must be reduced as much as possible due to the dead space, so that the wiring direction near the connection region of the flexible wiring substrate 30 is perpendicular to the long direction of the multilayer ceramic substrate 34. There is a need.

In the liquid crystal display device 14, the terminals of the drive circuit elements 27 and 29 are wire-bonded 33 to the wiring 32, and the wiring 38 of the laminated ceramic substrate 34 is connected to the wiring 32 via a conductive adhesive 40. 6, the conductive adhesive 40 and the wiring 32 increase the wiring resistance. However, as shown in FIG. The terminals 27 and 29 are wire-bonded 45 to the wiring 44 (nickel / gold lamination) on the multilayer ceramic substrate 43 so that the conductive adhesive 40 is not required. Adhere to the substrate 15. With such a configuration, the conductive adhesive 40
And the wiring 32 eliminates the wiring resistance. As a result, a high quality image without crosstalk can be obtained.

[0025]

As described above, according to the liquid crystal display device of the present invention, the signal input wiring pattern is constituted by a multilayer wiring board in which wiring layers and insulating layers are alternately laminated. The wiring area is smaller than the two-dimensionally wired space, the bonding area of the multilayer wiring board is smaller, and as a result, the dimensions of the liquid crystal display device itself are smaller, and downsizing can be achieved. Was.

According to the liquid crystal display device of the present invention, it is possible to provide a cover for protecting the wire bonding and each drive circuit element by setting the above-mentioned multilayer wiring board to a required height. Improves impact resistance.

Further, according to the liquid crystal display device of the present invention, the wiring resistance of the multilayer wiring board is reduced by forming the wiring so that the resistivity is reduced, thereby preventing image defects such as crosstalk. I was able to.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a partial cross section of a liquid crystal display device of an embodiment.

FIG. 2 is a plan view of the liquid crystal display device of the embodiment.

FIG. 3 is a cross-sectional view taken along line XX of FIG. 2;

FIG. 4 is an exploded perspective view of the multilayer ceramic substrate shown in the example.

FIG. 5 is a perspective view of a liquid crystal display device according to another embodiment.

FIG. 6 is a sectional view of a liquid crystal display device according to another embodiment.

FIG. 7 is a partial plan view of a conventional liquid crystal display device.

FIG. 8 is a partial plan view of a conventional liquid crystal display device.

[Explanation of symbols]

 15, 16: glass substrate 27, 29: drive circuit element 31, 33: wire bonding 34: multilayer ceramic substrate 40: conductive adhesive

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-17482 (JP, A) JP-A-63-163885 (JP, A) JP-A 1-115033 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) G02F 1/1345 G02F 1/1343 G09F 9/00-9/46

Claims (1)

(57) [Claims] A liquid crystal is sealed between two opposing glass substrates to form a display area, and each glass in the display area is formed.
In a liquid crystal display device, electrodes are arranged on the inner surface of a substrate, and the electrodes are connected to signal input wiring arranged in a region other than the display region of the substrate, wherein the signal input wiring is formed of a wiring layer and a ceramic. A length consisting of alternately stacked substrates
Constituted by elongated multilayer wiring board, one of the glass base
A liquid crystal display device, wherein the liquid crystal display device is arranged along an end face of a plate .