JP2987903B2 - Liquid crystal display - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, a liquid crystal display device comprising a driving LSI for driving the liquid crystal display device, a data signal circuit board, and a scanning signal circuit board. .

[Conventional technology]

Conventionally, liquid crystal display devices using TN type liquid crystal cells have been the mainstream, but in recent years the size, thickness, and capacity of dot matrix type liquid crystal display devices have rapidly increased. The number of divisions has increased, and it has become difficult to deal with the time-division characteristics of conventional TN-type liquid crystal display elements.
With the time-sharing characteristic of 1/64 duty or more, display characteristics such as contrast and viewing angle are deteriorated.

Therefore, recently, instead of such a TN type,
A liquid crystal display element of a display mode of a mode called SBE type or STN type has been proposed and has already been put to practical use. But,
Recently, high-density mounting of driving LSIs is important to achieve miniaturization, thinning, and high capacity of liquid crystal display devices. In general, metal bumps are formed on the drive LSI bare chip, and the TAB method is connected by pressure bonding to the electrodes patterned on the polyimide tape. The COB method mounted on a substrate has been put to practical use. Specifically, in the case of the TAB method or the COB method, the driving LSI is mounted on a data signal circuit board and a scanning signal circuit board provided outside the liquid crystal display element.
And a method of connecting both circuit boards has been used. In the case of the COG method, a method of arranging and connecting an LSI chip on a pattern extended from a display transparent electrode of a liquid crystal cell substrate has been used.

[Problems to be solved by the invention]

In such a liquid crystal display device, a tape carrier (TAB), an LSI chip, or the like is used as a driving LSI, and the driving LSI is mounted on a data signal circuit board and a scanning signal circuit board made of a glass epoxy substrate, a polyimide substrate, or the like. As shown in the figure, these circuit boards are arranged outside the liquid crystal display element. In FIG. 3, 31 is a liquid crystal display element, 32 is a data signal circuit board, 33 is a scanning signal circuit board, 34 and 35 are tape carriers (TAB), and 36 is a connector. However, in such a configuration, the outer shape of the liquid crystal display device becomes very large, and it has been difficult to reduce the size.

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the disadvantages of the prior art and to provide a miniaturized liquid crystal display device which can be configured with almost no change in the external dimensions of the liquid crystal display element.

[Means for solving the problem]

In order to achieve the above object, in the present invention, a liquid crystal display element,
In a liquid crystal display device including a driving LSI for driving the liquid crystal display element and a data signal circuit board and a scanning signal circuit board having a bus line pattern for inputting a signal to the driving LSI, a data signal circuit board is provided. And a bus line electrode terminal portion for connecting a bus line pattern of the scanning signal circuit board is disposed on an edge portion of each of the circuit boards cut at an angle of 45 degrees, and the circuit board is connected to the liquid crystal. The connection was made by positioning and positioning the lower part of the display element.

[Action]

According to the present invention, the bus line electrode terminals for connecting the bus line patterns of the data signal circuit board and the scanning signal circuit board are respectively arranged on the edges of one of the two circuit boards cut at an angle of 45 degrees. Since the two circuit boards are disposed and connected below the liquid crystal display element and connected, the liquid crystal display device can be configured without substantially changing the external dimensions of the liquid crystal display element.

〔Example〕

 Hereinafter, the present invention will be described in detail with reference to examples.

Embodiment 1 FIG. 1 is a view showing a liquid crystal display device according to a first embodiment of the present invention. FIG. 1 (a) is an expanded view of a data signal circuit board and a scanning signal circuit board, and FIG. Shows a state of assembling, and FIG. 4C shows a rear surface. First, the structure of the liquid crystal display element 1 will be described. A transparent electrode for display made of ITO or the like is formed on each of an upper substrate and a lower substrate, and an alignment film is formed and an alignment process is performed. The pair of upper and lower substrates are spaced apart and opposed to each other, are sealed with a sealant while maintaining a uniform gap by a gap material, and a liquid crystal is sealed between them to form a liquid crystal layer. Have been. An upper polarizing plate and a lower polarizing plate are provided above and below the liquid crystal display element 1, respectively.

TAB2,3 in which LSI chips 2a, 3a are mounted on a tape patterned on a polyimide substrate is used for the driving LSI,
The data signal electrode ED and the scanning signal electrode ES of the liquid crystal display element 1 are thermocompression bonded via an anisotropic conductive film. The TAB 2 on the data signal electrode side and the data signal circuit board 4 made of 0.4 mm thick glass epoxy, and the TAB 3 on the scan signal electrode side and the scan signal circuit board 5 are soldered, respectively. The data signal circuit board 4 and the scanning signal circuit board 5 are TA
The output outer leads of B2 and B3 are folded back to be disposed below the data signal electrode ED and the scanning signal electrode ES of the liquid crystal display element 1, respectively. The bus line electrode terminal portions 6 and 7 of the data signal circuit board 4 and the scanning signal circuit board 5 are formed such that one side connected to both boards is cut at 45 degrees and the cut edge portions 8 and 9 are respectively formed. I have. The arrangement of the data signal circuit board 4 and the scanning signal circuit board 5 is L-shaped, and the bus line electrode terminals 6, 7 are aligned so as to overlap each other. This bus line electrode terminal 6,7
Are previously plated with solder, and are connected by heating the electrode terminal portions 6 and 7 or by pouring solder.

With such a configuration, the liquid crystal display device according to the present embodiment has two upper, lower, left, and right sides in accordance with the external dimensions of the liquid crystal display element.
Very small size can be achieved just by expanding the size by ~ 3mm. The data signal circuit board 4 and the scanning signal circuit board 5 have a glass epoxy board of about 0.1 to 0.8 mm thickness,
Alternatively, a polyimide FPC substrate having a thickness of about 0.05 to 0.2 mm can be used.

Embodiment 2 FIG. 2 is a view similar to FIG. 1 (a) showing a liquid crystal display device according to a second embodiment of the present invention. This embodiment is similar to the first embodiment.
In such a configuration, as shown in the figure, a data signal circuit board and a scanning signal circuit board are mounted on a glass epoxy board.
Using an COB with an LSI chip mounted by wire bonding, the output electrode on the COB and the data signal electrode and the scanning signal electrode of the liquid crystal display element are made of polyimide, polyester, etc., made of FPC with Cu pattern, conductive resin pattern, etc. Are connected via an anisotropic conductive film. With such a configuration, the same effect as in the first embodiment can be obtained.

Embodiment 3 FIG. 4 is a view similar to FIG. 1 (c), showing a liquid crystal display device according to a third embodiment of the present invention. In the present embodiment, in the configuration as in the first embodiment, the arrangement of the data signal circuit board and the scanning signal circuit board is L-shaped as shown, and the bus line electrode terminals are aligned so as to face each other. . At this time, the bus line electrode terminals do not overlap and are arranged on the same plane. A connector is arranged and positioned on the upper surfaces of these two electrode terminal portions, and the connection is made by pouring solder. With such a configuration, the positioning of the two electrode terminals can be easily performed, and the same effect as in the first embodiment can be obtained.

〔The invention's effect〕

As described above in detail, according to the present invention, a liquid crystal display element and a driving LS for driving the liquid crystal display element
In a liquid crystal display device comprising a data signal circuit board and a scanning signal circuit board having a bus line pattern for inputting a signal to an I and its driving LSI, the bus line patterns of the data signal number board and the scanning signal circuit board are connected. Bus line electrode terminals for
Since the two circuit boards were arranged and connected at the lower part of the liquid crystal display element and connected to one edge cut at an angle of 45 degrees, the external dimensions of the liquid crystal display element were hardly changed. A liquid crystal display device can be configured.

[Brief description of the drawings]

FIG. 1 shows the configuration of the liquid crystal display device of Embodiment 1.
FIG. 2A is a development view, FIG. 2B is an assembly view, and FIG.
Is a rear view. FIG. 2 is a view similar to FIG. 1 (a) showing the configuration of the liquid crystal display device of Example 2. FIG. 3 is a perspective view showing the structure of a conventional liquid crystal display device, and FIG.
FIG. 2 is a view similar to FIG. 1 (c), showing the configuration of the liquid crystal display device of FIG. 1 ... Liquid crystal display element 2,3 ... Tape carrier (TAB) 4 ... Data signal circuit board 5 ... Scan signal circuit board 6,7 ... Bus line electrode terminal

Claims (3)

(57) [Claims] 1. A data signal circuit board and a scan signal circuit board having a liquid crystal display element, a driving LSI for driving the liquid crystal display element, and a bus line pattern for inputting a signal to the driving LSI. In the liquid crystal display device, bus line electrode terminals for connecting bus line patterns of the data signal circuit board and the scanning signal circuit board are respectively arranged on edges of one side cut at an angle of 45 degrees of both circuit boards. A liquid crystal display device, wherein both circuit boards are positioned and arranged below the liquid crystal display element and connected. 2. The liquid crystal display device according to claim 1, wherein said two circuit boards are positioned and arranged directly below said liquid crystal display element and are directly connected. 3. The liquid crystal display device according to claim 1, wherein the two circuit boards are positioned and arranged below the liquid crystal display element and connected via a connector.