JPH0385587A - Display device - Google Patents

Abstract

PURPOSE:To reduce the resistance of a circuit pattern and the connecting resistance of the input terminal of an driving LSI and to miniaturize the insulating substrate of a display part by connecting the IC chip of an output terminal to the circuit pattern and connecting at least a part of the input terminal of the IC chip to the terminal of an outside control substrate. CONSTITUTION:The circuit pattern 3 on the insulating substrate 1 and the wiring 9 or the outside control substrate 8 are bridged by the IC chip such as a driving LSI 5. Therefore, among the terminals of the driving LSI 5, the input terminal 6a requiring low resistance can be connected to the wiring pattern 9 of the outside control substrate 8 in an almost resistance-free condition. Moreover, it is unnecessary to form an input circuit pattern used to connect the input terminals 6 and 9 on the insulating substrate 1. Thereby, the resistance of the circuit pattern and the connecting resistance of the input terminal are reduced and the insulating substrate of the display part is miniaturized.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to improvements in display devices such as liquid crystal display devices.

(Prior Art) In recent years, liquid crystal display devices having a structure as shown in FIG. 4 have come into use.

In this liquid crystal display device, two glass substrates 101 and 10 are used.
A liquid crystal 103 is sealed between the two glass substrates 101 to form a display section, and a driving LS 1104 is mounted face down on one of the glass substrates 101, and the output terminal 105 of the driving LSI is
A and input terminal 105b are directly bonded to circuit pattern 106a and input circuit pattern 106b on the upper surface of the glass substrate, respectively. Further, the FPC 108 connected to the input circuit pattern 106b via the conductive film 107 and the external mounting board 110 on which the wiring pattern 109 is formed are connected by solder 111, and each connection part is connected to the moisture-proof resin 112. is sealed with.

In such a liquid crystal display device, both the circuit pattern 106a and the input circuit pattern 106b on the glass substrate 101, or only the input circuit pattern 106b, are usually formed of a thin film of a low-resistance metal such as aluminum.

(Problem to be Solved by the Invention) However, when forming a circuit pattern using a low-resistance metal thin film as described above, a separate process for forming the circuit pattern on the metal thin film is required, resulting in the problem of an increase in the number of processes. there were.

This problem can be solved by photo-etching a transparent conductive film such as ITO to remove both circuit patterns 106a.

106b, the problem can be solved. However, in that case, the resistance of the circuit pattern itself increases, and
Circuit pattern and terminal 105a of driving LSI 104
, 105b also increases, the driving L
The SI power supply voltage begins to drop.

In the case of a small liquid crystal display device, this drop in power supply voltage does not significantly affect the display state, so it is not a big problem. p) For large liquid crystal display devices, the driving LS11
The number of outputs per 04 is large, the clock frequency is high, and the power consumption of the driving LSI and the current consumption of the liquid crystal display section are large. Therefore, especially when the resistance of the input circuit pattern 106b and the connection resistance of the input terminal 105b of the driving LSI become high, current cannot be instantaneously supplied and the effective voltage applied to the liquid crystal display section decreases, resulting in proper display. There was a problem that it became difficult to obtain the state.

The present invention has been made in view of the above-mentioned problems, and its purpose is to eliminate the need for a metal thin film circuit pattern formation process, and to provide resistors for input circuit patterns that require low resistance and input terminals for driving LSIs. An object of the present invention is to provide a display device that can reduce the connection resistance of the device and also reduce the size of the insulating substrate of the display section.

(Means for Solving the Problems) The display device of the present invention includes a circuit pattern formed on an insulating substrate of a display portion, an IC chip equipped with a circuit for driving the display portion, and a circuit pattern formed on an insulating substrate of a display portion, and a A display device comprising an external control board having wiring, an output terminal of the IC chip being connected to the circuit pattern, and at least a part of an input terminal of the IC chip being connected to a terminal of the external control board. This achieves the above objectives.

(Function) In the display device of the present invention having the above configuration, the circuit pattern on the insulating substrate and the wiring on the external control board are bridged by an IC chip such as a driving LSI. Therefore, among the terminals of the driving LSR, input terminals that require low resistance, such as terminals for inputting external power supply and control signals, are made to have almost no resistance by means of wire bonding or tape automation rad bonding. This makes it possible to connect to the wiring pattern of an external control board, and it becomes possible to reduce the resistance of the circuit pattern by eliminating the need to form an input circuit pattern on an insulating board to connect the input terminals. .

Furthermore, in the display device of the present invention, since the input terminal of an IC chip such as a driving LSI can be mounted in a state protruding from the insulating substrate, the area for mounting the driving LSI on the insulating substrate can be reduced. be able to. Furthermore, an input circuit pattern for connecting the input terminals is not required. Therefore, the insulating substrate can be downsized.

(Example) Hereinafter, the present invention will be described with reference to examples.

FIG. 1 is a partial sectional view showing a liquid crystal display device according to an embodiment of the present invention, and FIG. 2 is a partial plan view of the same device with the moisture-proofing resin omitted.

In the figure, 1.2 is an insulating substrate made of a glass plate, and a circuit pattern 3 made of a photoetched transparent conductive film such as ITO is formed on the opposing surface of these insulating substrates 1.2. . Then, both insulating substrates 1.
A liquid crystal 4 is sealed between the substrates 2 to constitute a display section (display panel).The end portion 3a of the circuit pattern 3 on the insulating substrate 1 is extended laterally.

5 is a driving LSI for driving the display section. The driving LSI 5 is mounted face down on the insulating substrate 1 so that the bump electrodes 6a which constitute input terminals for power and control signals protrude outside the insulating substrate 1, and the bump electrodes 6a which constitute the output terminals protrude outward from the insulating substrate 1. 6b is conductive paste 7
It is directly bonded to the end portion 3a of the circuit pattern 3 on the insulating substrate l via the insulating substrate l.

8 is an external control board on which a wiring pattern 9 is formed. The inner lead 11 of the tape carrier 10 attached to this external control board 8 has a drive L.
The SI bump electrode 6a is connected. Moisture-proofing resin 12 is coated on the driving LSI 5 and each connection portion to protect the drive LSI 5 and each connection portion from intrusion of moisture that would have an adverse effect.

In this embodiment, the input terminal bump electrode 6a is connected to the drive L
Although the bump electrode is formed on the SI 5, the bump electrode may be formed on the tip of the inner lead 11 of the tape carrier 10. Further, in this embodiment, after the driving LSI 5 is mounted on the insulating substrate 1, the inner leads 11 of the tape carrier 10
However, conversely, the driving LSI 5 may be mounted on the insulating substrate l after the inner leads 11 are connected.

Like the liquid crystal display device with the above configuration, the bump electrodes 6b forming the output terminals of the driving LS 5 are directly bonded to the circuit pattern 3 of the insulating substrate 1, and the bump electrodes 6a forming the input terminals are controlled externally. When the circuit pattern 3 and the wiring pattern 9 are bridged and connected by the driving LSr 5 by tape automation rad bonding to the wiring pattern 9 of the board 8, the input terminal bump electrode 6a, which requires low resistance, can be connected with almost no resistance. Since it is not necessary to form an input circuit pattern on the insulating substrate 1, the resistance of the circuit pattern is also reduced.

Therefore, it is possible to achieve low resistance without forming the input circuit pattern with a low-resistance metal thin film as in the past, which is a great advantage in terms of manufacturing. When applied to display devices that require low resistance,
It becomes possible to effectively prevent deterioration of display quality.

Moreover, the circuit pattern 3 on the output side of the driving LSI 5, which does not require low resistance, can have any configuration, and the circuit pattern 3 can be formed at a minute pitch, so it is satisfactory in terms of fine-line compatibility. becomes.

Further, as in the above-mentioned liquid crystal display device, when the input terminal bump electrode 6a protrudes from the insulating substrate l, the driving L
When the SI5 is installed, the drive LSI mounting area of the insulating substrate 1 becomes smaller, which eliminates the need to form an input circuit pattern, and this makes it possible to make the insulating substrate 1 smaller than before, making it possible to use fewer materials. You will be able to save money.

FIG. 3 is a partial sectional view showing another embodiment of the present invention.

In this liquid crystal display device, a bump electrode 6a forming an input terminal of a driving LSI 5 and an external control board 8
The wiring pattern 9 is wire-bonded with a thin metal wire 13. Since the other configurations are the same as those of the previous embodiment, the same members are given the same reference numerals in FIG. 3, and detailed explanation will be omitted.

It goes without saying that even when the connection is made by wire bonding instead of tape automated bonding, a similar reduction in resistance can be achieved.

The present invention has been described above using a liquid crystal display device as an example.
The present invention is not limited to liquid crystal display devices, but can be applied to all display devices that require low resistance on the input side.

(Effects of the Invention) As is clear from the above description, the display device of the present invention has the following effects:
Since the process of forming a metal thin film circuit pattern on an insulating substrate is no longer necessary, the number of manufacturing steps can be reduced, and it is also suitable for input-side circuit resistance and drive LSIs that require low resistance.
Since the connection resistance of the input terminal of the input terminal can be reduced, it is possible to effectively prevent deterioration of display quality, and the insulating substrate can be made smaller, so material costs can be saved.

Figure 1 is a partial sectional view of one embodiment of the present invention, Figure 2 is a partial plan view of the same device with the moisture-proofing resin omitted, and Figure 3 is another embodiment of the present invention. FIG. 4 is a partial sectional view of a conventional display device.

1... Insulating substrate, 3... Circuit pattern, 5...
Driving LSI, 6a... Bump electrode forming an input terminal, 6b... Bump electrode forming an output terminal, 8...
・External control board, 9...Wiring pattern.

that's all

Claims (1)

[Claims] 1. A circuit pattern formed on an insulating substrate of a display section,
A display device comprising an IC chip equipped with a circuit for driving the display section and an external control board having wiring from an external circuit, the output terminal of the IC chip being connected to the circuit pattern, A display device in which at least a part of the input terminals of the IC chip are connected to terminals of the external control board.