JPH02259728A - Liquid crystal display device - Google Patents

Abstract

PURPOSE:To miniaturize a liquid crystal display device and to reduce mounting cost by forming a common electrode in structure obtained by laminating a transparent conductive film and an upper layered metal provided through an interlayer insulating film having a connection hole on the transparent conductive film. CONSTITUTION:The common electrode 16 of the liquid crystal display device is constituted of the transparent electrode film 18 and the upper wiring 24 provided through the interlayer insulating film 20. A power source and a control signal are supplied from the common electrode 16 to a semiconductor integrated circuit 14 through the upper wiring 24. The insulating film 20 having insulating ability is formed on the crossed area of the upper wiring 24 with the adjacent transparent conductive film 18 being the lower layer of the common electrode 16 between the wiring 24 and the conductive film 18, so that short circuit between the conductive film 18 and the wiring 24 is prevented. The connection area among a projecting electrode 25 formed on the circuit 14, the common electrode 16 and an output electrode 34 is constituted of one layer of the transparent conductive film 18. Then, the power source and the control signal are inputted in the circuit 14 from the common electrode 16 through the upper wiring 24 and the circuit 14 outputs an image to be displayed to the output electrode 34.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to the structure of a liquid crystal display device, and in particular to the structure of a common electrode for supplying power and control signals to a semiconductor integrated circuit mounted on a substrate of a liquid crystal display device. Regarding structure.

[Conventional technology]

Expanding the periphery of the glass substrate that makes up the liquid crystal display device,
A conventional example of mounting a plurality of semiconductor integrated circuits in this expanded area is, for example, the one described in Japanese Patent Application Laid-Open No. 62-44787. The structure of the liquid crystal display device described in this publication is shown in FIG.

A common electrode 16 in which a transparent conductive film is directly coated with nickel, copper, etc., and an output electrode 64 are provided on the substrate 12. The semiconductor integrated circuit 14 is fixed onto an insulating flexible film substrate 28 on which a first conductive wire 30 and a second conductive wire 32 are formed. The first conductive wire 30 and the second conductive wire 32 are connected to the semiconductor integrated circuit 14 by a bonding wire 66. The flexible film substrate 28 and the substrate 12 are connected by soldering to the common electrode 16 and the output electrode 64.
By connecting the first conductive wire 60 and the second conductive wire 62, the flexible film substrate 28 on which the semiconductor integrated circuit 14 is mounted is fixed onto the substrate 12.

Power and control signals are input to the semiconductor integrated circuit 14 through the common electrode 16 via the first conducting wire 30, and the semiconductor integrated circuit 14 inputs an output signal for displaying an image to the second conductor 30.
It outputs to the output electrode 64 via the conducting wire 32 .

[Problem to be solved by the invention]

The prior art described with reference to FIG. 2 has the advantage that the common electrode 16 and the semiconductor integrated circuit 14 can be connected without using double-layer wiring or jumper wires. However, since the semiconductor integrated circuit 14 is connected to the flexible film substrate 28 and the flexible film substrate 28 is mounted on the substrate 12, it is not sufficient to cope with miniaturization of the liquid crystal display device. Moreover, bonding wire 3
6, the semiconductor integrated circuit 14 and the flexible film substrate 28
and then connect the flexible film substrate 2 with solder.
8 and the substrate 12 are connected. Therefore, there is a problem that the implementation cost becomes high.

An object of the present invention is to be able to respond to miniaturization of liquid crystal display devices, and to
Furthermore, it is an object of the present invention to provide a structure of a liquid crystal display device with low mounting cost.

[Means to solve the problem]

In order to achieve the above object, the common electrode of the present invention has a laminated structure of a transparent conductive film and an upper metal layer provided on the transparent conductive film with an interlayer insulating film provided with connection holes interposed therebetween.

〔Example〕

Embodiments of the present invention will be described below with reference to FIG.

FIG. 1(a) is a plan view showing the configuration of a liquid crystal display device according to the present invention, and FIG.
It is a sectional view showing a cross section. Note that FIG. 1 shows one semiconductor integrated circuit mounting area of a liquid crystal display device in which a plurality of semiconductor integrated circuits are mounted on a substrate.

The common electrode 16 is composed of a transparent conductive film 18 and an upper layer wiring 24 provided through a connection hole 22 in an interlayer insulating film 20. The area where the transparent conductive film 18 and the upper layer wiring 24, which are laminated through the interlayer insulating film 20 having insulating properties, overlap vertically is
The transparent conductive film 18 and the upper layer wiring 24 are formed in the same plane pattern.

Power and control signals are supplied from the common electrode 16 to the semiconductor integrated circuit 14 through the upper layer wiring 24. The intersection area between the upper layer wiring 24 and the transparent conductive film 18 below the adjacent common electrode 16 is covered with an interlayer insulating film 20 having an insulating property.
is formed between the two, so that no short circuit occurs between the transparent conductive film 18 and the upper layer wiring 24.

The connection region between the protruding electrode 26 formed on the semiconductor integrated circuit 14 and the common electrode 16 and output electrode 64 is made of a transparent conductive film 181 layer.

Power and control signals are input from the common electrode 16 to the semiconductor integrated circuit 14 via the upper layer wiring 24, and the semiconductor integrated circuit 14 sends signals for displaying an image to the output electrode 3.
Output to 4.

Next, a manufacturing method for forming the above structure will be explained with reference to FIG.

First, a solid solution of indium oxide A (In2O5) and tin oxide (Sn02), so-called ITO, is formed as a transparent conductive film 18 on the entire surface of the substrate 12 to a thickness of about 200 nm by vacuum evaporation or sputtering. After that, the transparent conductive film 18 is etched by photoetching,
A lower layer film of the common electrode 16 is formed of the transparent conductive film 18, a part of which is indicated by the broken line in FIG. 1(a). This step of forming the transparent conductive film 18 is performed simultaneously with the formation of pixel electrodes of the liquid crystal display device. In addition to the above-mentioned ITO, the transparent conductive film 18 may be made of a material with high transmittance in the visible range and good conductivity, such as tin oxide with antimony oxide added, or zinc oxide with aluminum oxide added. Applicable.

Next, as an interlayer insulating film 20, a silicon nitride film (SixNy) is deposited to a thickness of 400 mm over the entire surface by plasma chemical vapor deposition.
Form about nm. Thereafter, this interlayer insulating film 20 is etched by photo-etching to form a connection hole 22. As the interlayer insulating film 20, in addition to the silicon nitride film, an inorganic insulating film such as a silicon oxide film, or an organic insulating film such as a polyimide resin can be used. This interlayer insulating film 2
In the passive matrix method, which drives the liquid crystal in a time-division manner, 0 can also be used as an alignment film for aligning the liquid crystal, and in the active matrix method, in which thin film transistors and nonlinear elements are placed in each pixel, and these active elements drive the liquid crystal. In the matrix method, an interlayer film provided between the semiconductor film and the wiring can also be used.

Next, as the upper layer metal 24, 500% aluminum is applied to the entire surface.
The metal layer 24 is formed to a thickness of approximately nm by vacuum evaporation or sputtering, and photoetched to form an upper layer metal 24 as an upper layer film of the common electrode 16. Upper layer metal 24
In addition to a metal film such as aluminum, the film may be made of a high melting point metal such as molybdenum, or a silicide thereof. This upper layer metal 24 can also be used as wiring in the active matrix method.

The substrate 12 and the semiconductor integrated circuit 14 can be connected by using a conductive adhesive, or by using an insulating adhesive in which the protruding electrodes 26 are made of a soft metal and which is thermosetting or ultraviolet curable and generates shrinkage stress after curing. This can be done using a method using

The common electrode 16 in the present invention has a two-layer structure including a transparent conductive film 18 and an upper metal layer 24 with an interlayer insulating film 20 interposed therebetween. Therefore, it is possible to connect the common electrode 16 and the semiconductor integrated circuit 14 without using a flexible film substrate as in the conventional example shown in FIG. can do.

Further, the common electrode 16 has a two-layer structure including a transparent conductive film 18 and an upper metal layer 24 via a plurality of connection holes 22 formed at regular intervals in an interlayer insulating film 20. Therefore, compared to the conventional structure in which a transparent conductive film is directly coated with nickel, copper, etc., the common electrode 16 in the present invention has a structure in which disconnection is less likely to occur.

Note that in the above explanation, an example is given in which a conductive adhesive or an insulating adhesive is used to connect the substrate 12 and the semiconductor integrated circuit 14, but the upper layer metal 24 may be made of a solderable metal such as nickel or copper. Structure (The protruding electrodes 26 may be made of solder and the solder may be melted to connect the substrate 12 and the semiconductor integrated circuit 14. Alternatively, the upper layer metal 24 may be made of a wire-bondable metal such as aluminum or gold. However, the substrate 12 and the semiconductor integrated circuit 14 may be connected by bonding wires.

Furthermore, although the region where the transparent conductive film 18 and the upper metal layer 24 overlap in the vertical direction has been described as an example in which the area is configured with the same plane pattern, the transparent conductive film 18 and the upper layer metal 24 are not configured in the same plane pattern. It's okay. For example, the upper layer metal 24
By making the pattern width larger than the pattern width of the transparent conductive film 18, the wiring resistance of the common electrode 16 can be lowered.

〔Effect of the invention〕

As is clear from the above description, the configuration of the liquid crystal display device of the present invention can achieve miniaturization of the liquid crystal display device and reduction in mounting cost.

[Brief explanation of drawings]

FIGS. 1(a) and 1(b) show the structure of a liquid crystal display device according to the present invention, FIG. 1(a) is a plan view, and FIG. 1(b) is a cross section taken along line A-A in FIG. The cross-sectional view and FIG. 2 are perspective views showing the structure of a conventional liquid crystal display device. 14... Semiconductor integrated circuit, 16... Common electrode, 18... Transparent conductive film, 20...
・Interlayer insulating film, 22... Connection hole, 24...
...Upper layer wiring. Figure 1 16, common IT pole 22, Shobonana 1 Muno 18, Toru [1 Noson 1 gland]

Claims (1)

[Scope of Claims] A substrate having a plurality of pixel electrodes, a plurality of semiconductor integrated circuits mounted on the substrate, and a common substrate formed on the substrate for supplying power and control signals to the semiconductor integrated circuits. In the liquid crystal display device comprising an electrode, the common electrode includes a transparent conductive film provided on the substrate, and an upper layer metal provided on the transparent conductive film with an interlayer insulating film provided with a connection hole interposed therebetween. Characteristic liquid crystal display device.