JPH04106528A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To allow the constitution of the device with substantially no change in the outside dimensions of the display element by positioning, disposing and connecting the bus line electrode terminal parts of a data signal circuit board and a scanning signal circuit board respectively to the edges on one side cut at 45 deg. angle of the two circuit boards. CONSTITUTION:The bus line electrode terminal parts 6, 7 of the circuit board 4 and the circuit board 5 are respectively formed in the edges 8, 9 cut at 45 deg. of the two circuit boards. The circuit board 4 and the circuit board 5 are disposed in an L shape and are so positioned that the terminal parts 6, 7 overlap on each other. These terminal parts 6, 7 are previously plated with solder and are connected by heating the terminal parts 6, 7 or by pouring solder therein. The device is merely expanded by 2 to 3mm vertically and laterally than the outside dimensions of the liquid crystal display device if the device is formed in such a manner. The device is thus miniaturized.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a liquid crystal display device comprising a liquid crystal display element, a driving LSI for driving the liquid crystal display element, a data signal circuit board, and a scanning signal circuit board. 6 [Prior art] Conventionally, the mainstream of liquid crystal display devices has been those using TN type liquid crystal cells, but in recent years, dot matrix type liquid crystal display elements have become smaller, thinner, and have higher capacity. The number of time divisions is increasing rapidly, and it is becoming difficult to cope with the time division characteristics of conventional TN type liquid crystal display elements.
In particular, when using time division characteristics with a duty of 1164 or more, display characteristics such as contrast and viewing angle deteriorate.

Therefore, recently, instead of such a TN type,
A liquid crystal display element with a display mode called an SBR type or an STN type has been proposed and has already been put into practical use. However, recently, in order to make liquid crystal display devices smaller, thinner, and higher in capacity, high-density packaging of driving LSIs has become important. -For boat fishing, there is a TAB method in which metal bumps are formed on a driving LSI bare chip and the electrodes are crimped and connected to patterned electrodes on polyimide tape, a COG method in which the LSI bare chip is directly mounted on a liquid crystal cell substrate, or A COB method mounted on a circuit board has been put into practical use. Specifically, in the case of the TAB method or the COB method, a method is used in which a driving LSI is placed on a data signal circuit board and a scanning signal circuit board provided outside the liquid crystal display element, and the peripheral circuit board is connected. I've been exposed to it. Furthermore, in the case of the COG method, a method has been used in which an LSI chip is arranged and connected on a pattern extending from a display transparent electrode of a liquid crystal cell substrate.

[Problem 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 the driving LSI, and it is mounted on a data signal circuit board and a scanning signal circuit board made of a glass epoxy substrate, a polyimide substrate, etc.
As shown in the figure, these circuit boards are placed 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.
35 is a tape carrier (TAB), and 36 is a connector. However, in the case of such a configuration, the external size of the liquid crystal display device becomes extremely large, making it difficult to miniaturize the device.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate such drawbacks of the prior art and to provide a miniaturized liquid crystal display device that can be constructed with almost no difference in external dimensions from the liquid crystal display element.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a data 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 signals to the driving LSI. In a liquid crystal display device consisting of a scanning signal circuit board, the bus line electrode terminal portion for connecting the bus line patterns of the data signal circuit board and the scanning signal circuit board is each cut on one side of the peripheral circuit board at a 45 degree angle. The peripheral circuit board is positioned and connected to the lower part of the liquid crystal display element.

[Effect]

According to the present invention, the bus line electrode terminal portions for connecting the bus line patterns of the data signal circuit board and the scanning signal circuit board are arranged at the edge portion of one side of the peripheral circuit board cut at an angle of 45 degrees. Since the peripheral circuit board is positioned and connected under the liquid crystal display element, it is possible to construct a liquid crystal display device without changing the external dimensions of the liquid crystal display element.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to Examples.

Embodiment 1 FIG. 1 is a diagram showing a liquid crystal display device according to a first embodiment of the present invention. FIG. 1(a) shows a data signal circuit board and a scanning signal circuit board developed, and FIG. 1 shows the assembled state, and FIG. 2(e) shows the back side.

First, the structure of the liquid crystal display element 1 will be described. Transparent display electrodes made of ITO or the like are formed on the upper substrate and the lower substrate, respectively, and an alignment film is further formed and subjected to alignment treatment. This pair of upper and lower substrates are spaced apart and arranged facing each other,
The gaps are sealed with a sealant while maintaining uniform intervals, and the liquid crystal is sealed between them to form a liquid crystal layer.
A liquid crystal display element l is configured. An upper polarizing plate and a lower polarizing plate are provided above and below the liquid crystal display element 1, respectively.

The driving LSI is a TAB with LSI chips 2a and 3a mounted on a tape patterned on a polyimide substrate.
2.3 is used, and the data signal electrode E of the liquid crystal display element 1
D and the scanning signal electrode ES are bonded by thermocompression via an anisotropic conductive film. TAB2 and 0°4 on this data signal electrode side
A data signal circuit board 4 made of thick glass epoxy and a TAB 3 on the scanning signal electrode side are soldered to the scanning signal circuit board 5, respectively. The data signal circuit board 4 and the scanning signal circuit board 5 are arranged below the data signal electrode ED and the scanning signal electrode ES of the liquid crystal display element 1 by folding back the output outer lead portions of the TABs 2 and 3. The bus line electrode terminal parts 6 and 7 of the data signal circuit board 4 and the scanning signal circuit board 5 are cut at 45 degrees on one side where the open board is connected, and the cut edge part 8
．． 9, respectively. The data signal circuit board 4 and the scanning signal circuit board 5 are arranged in an L-shape and are aligned so that the bus line electrode terminal portions 6 and 7 overlap each other. This bus line electrode terminal portion 6.
7 is pre-soldered and connected by heating the picture electrode terminal portion 6°7 or by pouring solder into it.

With such a configuration, the liquid crystal display device according to this embodiment has a width of 2 to 20 mm in both the top, bottom, left and right sides of the external dimensions of the liquid crystal display element.
It is possible to make it extremely compact by just increasing the size by 3 meters. Note that for the data signal circuit board 4 and the scanning signal circuit board 5, a glass epoxy board with a thickness of about 0.1 to 0.8 mm or a polyimide FPC board with a thickness of about 0.05 to 0.2 mm should be used. I can do it.

Embodiment 2 FIG. 2 is a diagram similar to FIG. 1(a) showing a liquid crystal display device according to a second embodiment of the present invention. In this embodiment, in the configuration as in Embodiment 1, L is mounted on a glass epoxy substrate as a data signal circuit board and a scanning signal circuit board as shown in the figure.
CO with SI chip mounted by wire bonding
Using B, an anisotropic conductive film was formed on the 8-force electrode on the COB and the data signal electrode and scanning signal electrode of the liquid crystal display element using an FPC made of polyimide, polyester, etc. and on which a Cu pattern, a conductive resin pattern, etc. were formed. It is connected via With such a configuration, the same effects as in the first embodiment can be obtained.

Embodiment 3 FIG. 4 is a diagram similar to FIG. 1(c) showing a liquid crystal display device according to a third embodiment of the present invention. This embodiment has a configuration similar to that of Embodiment 1, but as shown in the figure, the arrangement of the data signal circuit board and the scanning signal circuit board is L-shaped, and the bus line electrode terminal portions are aligned so as to face each other. . At this time, the bus line electrode terminal portions do not overlap and are arranged on the same plane. A connector is arranged and aligned on the upper surface of this picture electrode terminal section, and connection is made by pouring solder. With such a configuration, alignment of the picture electrode terminal portions becomes easy, and the same effects as in the first embodiment can be obtained.

〔Effect of the invention〕

As explained in detail above, according to the present invention.

In a liquid crystal display device consisting of a liquid crystal display element, an active 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 signals to the driving LSI. , a bus line electrode terminal portion for connecting the bus line patterns of the data signal frequency board and the scanning signal circuit board is arranged on the edge of one side cut at an angle of 45 degrees of both circuit boards. Since the circuit board is positioned and connected under the liquid crystal display element, it is possible to construct a liquid crystal display device without changing the external dimensions of the liquid crystal display element.

[Brief explanation of drawings]

FIG. 1 shows the configuration of the liquid crystal display device of Example 1.
Figure (a) is an exploded view, figure (b) is an assembled view, figure (c)
is a back view. FIG. 2 is a diagram similar to FIG. 1(a) showing the configuration of a liquid crystal display device according to a second embodiment. FIG. 3 is a perspective view showing the configuration of a conventional liquid crystal display device, and FIG. 4 is a third embodiment.
2 is a diagram 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...Scanning signal circuit board 6.7...Bus line electrode terminal portion Patent applicant Co., Ltd. Rico

Claims (3)

[Claims] (1) A liquid crystal display consisting of a liquid crystal display element, 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 signals to the driving LSI. In the display device, the bus line electrode terminal portions for connecting the bus line patterns of the data signal circuit board and the scanning signal circuit board are respectively arranged at the edge portion of one side cut at a 45 degree angle of both circuit boards. . A liquid crystal display device, characterized in that both circuit boards are positioned and connected under the liquid crystal display element. (2) Claim characterized in that the two circuit boards are positioned and arranged under the liquid crystal display element and directly connected.
1) The liquid crystal display device described above. (3) The liquid crystal display device according to claim (1), wherein both circuit boards are positioned and arranged under the liquid crystal display element and connected via a connector.