JP2000022298A - Display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and accurately judge whether a connection state is proper or not only by conduction inspection. SOLUTION: In a device B, a flexible wiring board 2 is provided between a display panel 1 and a printed-circuit board 4, and conduction is made by a connection terminal row 5 being arranged on the flexible wiring board 2 and a connection terminal row 7 being arranged on the printed-circuit board 4 for fixing. Furthermore, dummy terminals 10 and 11 where conduction and fixing are made between both of them are arranged, and the terminals of the dummy terminal 10 are short-circuited.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display,
More particularly, the present invention relates to a display device in which a printed circuit board is juxtaposed with a display device, both of which are fixed with a flexible wiring board, and are electrically connected.

[0002]

2. Description of the Related Art In a display device such as a liquid crystal display device, the size is reduced by using a battery with low power consumption.
It has been made thinner and more portable. In such a display device, an IC chip for driving the display panel is mounted on a flexible wiring board on which drive circuit wiring is printed, and the substrate is provided on the display panel.
An AB type liquid crystal display device has been proposed.

Further, the flexible wiring board is connected and fixed to a printed board for inputting a signal to an IC chip.

[0004] A conventional liquid crystal display device will be described with reference to FIGS. FIG. 4 shows a main part of the liquid crystal display device A, and FIG. 5 is a sectional view taken along the line XX in FIG.

[0005] 1 is a display panel, 2 is a flexible wiring board, 3 is an IC chip provided on the flexible wiring board 2,
Reference numeral 4 denotes a printed circuit board, and reference numeral 5 denotes a connection terminal row made of copper or the like connected to the IC chip 3. Reference numeral 2a denotes a remaining end portion of the flexible wiring board 2 which is removed to expose the connection terminal row 5. A plurality of dummy terminals 6 are arranged near the end of the connection terminal row 5.

Further, a connection terminal row 7 is arranged on the printed circuit board 4, a plurality of dummy terminals 8 are also arranged near the end of the connection terminal row 7, and the connection terminal row is provided on each of the connection terminal row 7 and the dummy terminal 8. The rows 5 and the dummy terminals 6 are arranged, and the upper and lower terminals are fixed by covering the solder 9 to make them conductive.
Note that, instead of using the solder 9, an anisotropic conductive film may be used.

In the liquid crystal display device A having the above structure, in order to connect the flexible wiring board 2 and the printed circuit board 4, in addition to the connection terminal rows 5 and 7 required for display and driving,
Dummy terminals 6 and 8 are also formed. As a result, the stress concentrated on both ends of the connection terminal rows 5 and 7 is loaded by the dummy terminals 6 and 8, and the reliability of the connection state of the connection terminal rows 5 and 7 is increased.

[0008]

The above-described liquid crystal display device A
According to this, when a failure occurs in the connection between the flexible wiring board 2 and the printed board 4, the dummy terminals 6 and 8 are separated from each other and become non-conductive, but such a floating state S is visually inspected. It was excluded as a defective product.

However, in the actual appearance inspection, since the connection terminal rows 5 and 7 are surrounded by the solder 9, there is a problem that it is difficult to discriminate if strict inspection is performed, and accurate pass / fail cannot be performed.

Even when an anisotropic conductive film is used in place of solder, since the flexible wiring board 2 is made of, for example, a polyimide resin film having a thickness of 75 μm, strict inspection is difficult due to its opacity, and accurate Could not be determined.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a display device which can accurately determine the quality of a display, thereby increasing the yield and thereby reducing the production cost.

Another object of the present invention is to obtain a reliable connection so as to maintain display performance for a long time when a display device is used.

[0013]

SUMMARY OF THE INVENTION The present invention relates to a display device comprising a display panel and a printed circuit board connected via a flexible wiring board, wherein each terminal of the printed circuit board or the display panel and the flexible wiring board is connected. A plurality of connection terminal rows connected to each other and a plurality of dummy terminals are formed near the ends of the connection terminal rows, and the dummy terminals on the flexible wiring board side or the dummy terminals on the printed circuit board side and / or the flexible wiring are provided. The dummy terminals on the plate side or the dummy terminals on the display panel side are short-circuited.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A display device of the present invention will be described in detail with reference to FIGS. The same parts as those in FIGS. 4 and 5 are denoted by the same reference numerals.

FIG. 1 is a plan view of a main part of the liquid crystal display device B, and FIG. 2 is a cross-sectional view taken along the line Y--Y in FIG. FIG. 3 is a plan view of a main part of another liquid crystal display device C.

In the liquid crystal display device B, the display panel 1
Is connected to the flexible wiring board 2, and the IC chip 3 is provided on the flexible wiring board 2. A connection terminal row 5 made of copper or the like is led out of the IC chip 3, and the connection terminal row 5 is fixed to a connection terminal row 7 on the printed circuit board 4 by solder 9 and is energized.

In the present invention, a plurality of dummy terminals 10 are provided near the end of the connection terminal row 5 and a plurality of dummy terminals 11 are provided near the end of the connection terminal row 7. Both ends of these dummy terminals 10 are short-circuited in the flexible wiring board 2. For this purpose, the dummy terminal 10 may be formed in a U-shape as shown. The dummy terminal 11 is longer than the conventional dummy terminal 8 shown in FIG.

In order to provide the flexible wiring board 2 on the printed circuit board 4, alignment is performed between the connection terminal row 5 and the connection terminal row 7, and then both terminals are connected and fixed with the solder 9. At this time, the solder 9 is also connected between the individual terminals of the dummy terminal 10 and the dummy terminal 11.

In order to judge the quality of the connection state of the liquid crystal display device B, the state of conduction between the two terminals of the dummy terminal 11 is examined. Since the connection 11 is well connected to the other dummy terminal 11 via the dummy terminal 10, the connection is good between the connection terminal row 5 and the connection terminal row 7. On the other hand, if the connection is defective, the resistance value between the two dummy terminals 11 increases, and if the resistance value exceeds a certain value, it is determined to be defective.

Next, a liquid crystal display device C shown in FIG. 3 will be described as another example of the present invention. In the liquid crystal display device B, the connection was made by soldering, but an anisotropic conductive film was used instead. In other words, in connecting the connection terminal row 5 and the connection terminal row 7 exposed on the surface of the flexible wiring board 2 and the dummy terminal 10 and the dummy terminal 11 in the same manner, they are connected by an anisotropic conductive film. Also in this example, by checking the energized state between the two dummy terminals 11, if the energized state, a good connection is established, and the connection terminal row 5 and the connection terminal row 7 are connected. Good connection between them.

It should be noted that the present invention is not limited to the above embodiment, and various changes and improvements may be made without departing from the scope of the present invention.

For example, in the above example, the plurality of dummy terminals 10 are short-circuited in the flexible wiring board 2;
It may be short-circuited in the circuit of the C chip 3. In addition, although the dummy terminals 10 and 11 illustrate two terminals, three or more terminals may be provided. Furthermore, although the short circuit is made at the dummy terminal 10 of the flexible wiring board 2, the short circuit may be made at the dummy terminal group 11 of the printed circuit board 4 instead.

Furthermore, in the above embodiment, the connection state between the printed circuit board 4 and the flexible wiring board 2 is used. However, by using the display panel 1 instead of the printed circuit board 4, the display panel 1 and the flexible wiring board 2 are connected. The same operation can be obtained in the connection state with the wiring board 2.

[0024]

As described above, according to the display device of the present invention, between the flexible wiring board and the printed circuit board, or near the end of each connection terminal array arranged on the flexible wiring board and the display panel, between the two. By arranging the dummy terminals to be energized and fixed, and by short-circuiting between the dummy terminals in one of the dummy terminal groups, it is possible to easily and accurately determine whether the connection state is good or not by only the energization test, thereby increasing the manufacturing yield, Further, when the display device was used, good display performance could be maintained for a long period of time.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a main part of a liquid crystal display device of the present invention.

FIG. 2 is a cross-sectional view taken along line YY in FIG.

FIG. 3 is a schematic plan view showing a main part of another liquid crystal display device of the present invention.

FIG. 4 is a schematic plan view showing a main part of a conventional liquid crystal display device.

FIG. 5 is a sectional view taken along the line XX in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Display panel 2 Flexible wiring board 3 IC chip 4 Printed circuit board 5, 7 Connection terminal row 6, 8, 10, 11 Dummy terminal 9 Solder

Claims (1)

[Claims] 1. A display device comprising a display panel and a printed circuit board connected to each other via a flexible wiring board, wherein the printed circuit board or the display panel and a plurality of terminals each connected to the flexible wiring board are connected to each other. Connection terminal row,
A plurality of dummy terminals are formed near an end of the connection terminal row, and the dummy terminals on the flexible wiring board side or the dummy terminals on the printed circuit board side and / or the dummy terminals on the flexible wiring board side or the display panel side. Wherein the dummy terminals are short-circuited.