JPH01152489A - Liquid crystal display panel - Google Patents

Abstract

PURPOSE: To decrease the number of connection points between the liquid crystal plate and the outside and improve reliability, and reduce the area of the connection part by building a driving circuit for driving a cell part in a display plate main body. CONSTITUTION: An IC chip 4 for driving as the driving circuit for driving the cell part 10 is mounted on an external plate 7 as the display plate main body. Namely, a conductive pattern 8a formed by leading a transparent electrode 8 of the cell part 10 out as it is and the connection part on the driving IC chip 4 are connected through an anisotropic conductive film 15. Thus, the liquid crystal display plate 20 is mounted on a wiring board 1 and a wiring pattern 16 connected to the driving IC chip 4 and a wiring pattern 17 connected to an IC chip 2 for operation are electrically and mechanically connected. Consequently, only a power source, lines, etc., for information indicating a display pattern are connected to the outside and the reliability of the connection part can be improved, and the area of the connection part of the wiring board, etc., can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a liquid crystal display board that is incorporated into, for example, a multifunctional IC card.

(Prior Art) A conventional liquid crystal display panel used in a multifunctional IC card will be explained as an example. First, let's talk about multi-function IC cards. Multi-function IC cards have a pocket-sized card base with necessary electronic components such as an IC chip such as a CPU, a liquid crystal display board, and a thin battery mounted on a wiring board. On the surface of the card base, the display section of the liquid crystal display board is exposed to the outside through a suitably opened window, and a keyboard is also provided, and the required data can be exchanged with an external device such as a reader/writer. Contacts for sending and receiving etc. are provided.

FIG. 4 shows a portion where a liquid crystal display board is incorporated into the multi-function IC card as described above. In the figure, 1 is a wiring board, 2 is a calculation IC chip that is a CPU, and 3 is a liquid crystal display board.The liquid crystal display board 3 has 16 characters, and each character is 5
A structure made up of dots is used. A driving IC chip 4 serves as a driving circuit for driving the liquid crystal display panel 3, and is mounted on the wiring board 1 together with the calculation IC chip 2. The wiring pattern 5 on the wiring board 1 connected to the driving IC chip 4 and the conductive pattern 6 on the liquid crystal display panel 3 are connected by an anisotropic conductive film or the like. As mentioned above, the liquid crystal display board 3 has 16 characters, 5×7
Since dots/letters are used, there are 87 connection points between the wiring pattern 5 and the conductive pattern 6.

According to the 15O (International Organization for Standardization) standard, the thickness of a multifunctional IC card containing the above-mentioned electronic components is defined as 0.76±0.08 mm.
The horizontal dimensions are also regulated to predetermined dimensions. For this reason, each internal member and component is required to be small and compact.

In addition, multi-functional IC cards have the ability to record necessary information in various fields such as finance, distribution, and medicine, in which they are used. It also has functions such as checking the above-mentioned recorded contents by operating the CPU by manual operation of the keyboard without using a reader/writer. For this reason, multifunctional IC cards are required to be highly reliable.

(Problems to be Solved by the Invention) Conventionally, an IC chip 4 for driving a liquid crystal display board is connected to a wiring board 1.
As a result, the number of connection points between the wiring pattern 5 on the wiring board 1 side and the conductive pattern 6 on the liquid crystal display board 3 side increases, and the wiring density at the connection part increases, resulting in a decrease in reliability. There was a risk of inviting In addition, wiring board 1
The area for the connection part was also large.

This invention has been made based on the above circumstances, and it is possible to improve reliability by reducing the number of connection points between a liquid crystal display board and the outside, and to reduce the area of the connection parts. The purpose is to provide display boards.

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, the gist of the present invention is that a drive circuit for driving the cell section is built into the display board main body. .

In the above configuration, connections between the drive circuits and the cell section, which are required in large numbers, by drive signal lines are made inside the liquid crystal display panel, which is an individual component, and connections to the outside are made through the power supply and display characters. There are only lines of information indicating display patterns such as. Thus, the number of connection points between the liquid crystal display panel and the outside is significantly reduced.

(Example) Hereinafter, an example of the present invention will be described based on FIGS. 1 to 3. This embodiment is applied to a liquid crystal display board in a multifunctional IC card.

In FIGS. 1 to 3, the same or equivalent members as those in FIG. 4 are designated by the same reference numerals, and redundant explanation will be omitted.

First, to explain the structure of the liquid crystal display board, Figures 1 and 2.
In the figure, reference numeral 7 denotes an outer plate made of transparent plastic as the main body of the display panel, and a transparent electrode 8 is formed on one end side of the outer plate. At a portion facing this transparent electrode 8, another outer plate 11 made of transparent plastic and having a transparent electrode 9 as a counter electrode is attached with a sealing agent 12 serving as a spacer to form an airtight space. , a liquid crystal 13 is sealed in this airtight space. Further, a reflecting plate 14 is provided on the other side of the outer plate 11. The cell portion 10 is formed by the configuration of each member as described above. The cell section 10 is made up of 16 characters, each character consisting of 5.times.7 dots, as in the conventional cell section.

A driving IC chip 4, which is a driving circuit for driving the cell section 10, is mounted on the outer panel 7, which is the main body of the display panel. FIG. 3 shows an example of its implementation, in which a conductive pattern 8a in which the transparent electrode 8 in the cell part 10 is directly drawn out and a connection part on the driving IC chip 4 are connected via an anisotropic conductive film 15. Further, the driving IC chip 4 is appropriately molded with resin.

Note that the connection between the conductive pattern 8a and the driving IC chip 4 is performed by connecting the conductive pattern 8a to the driving IC chip 4 using a bump method or a wire bonding method, using only the connection portion as a metal film pattern. You can also do that.

As mentioned above, in this embodiment, a large number of cell parts 10 are required and a driving IC chip 4 for driving them.
The connection is made inside the liquid crystal display panel 20, which is an individual component.

The liquid crystal display board 20 configured as described above is mounted on the wiring board 1, and the wiring pattern 16 on the liquid crystal display board side connected to the driving IC chip 4 and the wiring board connected to the calculation IC chip 2 are mounted on the wiring board 1. The wiring pattern 17 on the first side is electrically and mechanically connected by an anisotropic conductive film. These electrical connections are made at 25 locations in total, including 8 address lines, 8 data lines, and 9 signal and power lines.

Since the liquid crystal display board 20 is configured as described above,
The number of connection points between the liquid crystal display board 20 and the wiring board 1, which is the outside thereof, is reduced from 87 to 25 compared to the conventional device. As a result, the possibility of occurrence of defects in the connection portions is significantly reduced, reliability is improved, and the area for the connection portions on the wiring board 1 is reduced. Here, if the area for the connection part were to be the same as that of the conventional one, the area per connection point would be more than three times that of the conventional one, so the connection could be ensured. As a result, reliability can be further improved.

When a key is pressed manually by keyboard operation, the drive I
A drive signal is output from the C chip 4, and a desired display is made on the cell section 10 of the liquid crystal display panel 20.

[Effects of the Invention] As explained above, according to the present invention, since the drive circuit for driving the cell section is built into the display board body, connection of a large number of drive circuits and cell sections, which are normally required, is eliminated. is compactly carried out inside the liquid crystal display board, and the only connections to the outside are the power supply and information lines for indicating the display pattern, which can be significantly reduced and the reliability of the connections can be improved. Furthermore, it is possible to reduce the area of a connecting portion on a wiring board or the like on which the liquid crystal display board is mounted. Therefore, it is possible to provide a liquid crystal display panel that is extremely suitable for being incorporated into a portable medium such as a multifunctional IC card.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of a liquid crystal display board according to the present invention, FIG. 2 is an enlarged sectional view taken along the line n-I in FIG. 1, and FIG. 3 is an example of mounting a driving IC chip in the same embodiment. FIG. 4 is a plan view of a conventional liquid crystal display panel. 4: driving IC chip as a driving circuit, 7: outer panel as a display board main body, 10: cell section, 20: liquid crystal display board.

Claims (2)

[Claims] (1) A liquid crystal display board characterized in that a drive circuit for driving a cell section is built into the display board body. (2) The liquid crystal display panel according to claim 1, wherein the drive circuit is integrated on an IC chip.