JPS60220317A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To obtain an element superior in moisture proof reliability in a high-temperature environment by forming an inorganic film as a protective film on a metallic thin film wiring with respect to the liquid crystal display element where a semiconductor chip for driving a liquid crystal is connected directly onto the metallic thin film wiring. CONSTITUTION:An NiCr film 12 which has a high adhesive strength to a glass of materials of a lower electrode substrate 11, where a lighting pattern is formed with a transparent conductive film 10, is formed on this substrate 11 so that a part of this film 12 is connected to the transparent conductive film 10. A Cu film 13 having a good solder-wetting property is formed on the film 12, and a double-layered film wiring 14 is formed by wiring patterning of photoetching. An inorganic film 15 consisting of an SiO2, an SiN, an Al2O3, or the like is formed to cover the whole of the surface and side faces of the double-layered film wiring 14 by vapor-deposition or the like, and thereafter, through holes are provided in parts to which a solder 16 should be connected. Next, the liquid crystal is sealed between the lower electrode substrate 11 and an upper electrode substrate 18 to assemble a liquid crystal cell, and a semiconductor chip 19 for driving the liquid crystal is connected to the double-layered film wiring 14 by the solder 16. The inorganic film 15 functions as a solder dam and makes the solder connection shape uniform.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a liquid crystal display element, and in particular, metal film wiring is patterned on one substrate constituting the liquid crystal display element, and a liquid crystal driving semiconductor is formed on the metal wiring. This relates to chip-on liquid crystal display devices that have chips directly connected to them.

[Background of the invention]

A conventional chip-on liquid crystal display element has a structure as shown in FIG. Multilayer metals, including metals with good solder wettability,
A sealant 3 is applied on the lower electrode substrate 2 on which the thin film wiring 1 is formed.
The upper electrode substrate 4 is fixed through the upper electrode substrate 4, and a liquid crystal is sealed between the lower electrode substrate 2 and the upper electrode substrate 4 to form a liquid crystal cell. Further, a liquid crystal driving semiconductor chip 6 is soldered onto the metal thin film wiring 1 via solder 5, and a resin coat 7.8 is applied to protect the liquid crystal driving semiconductor chip 6 and metal thin film wiring 1 from the external environment. is forming.

However, with such a structure, is it possible to coat the resin in a high temperature environment? Due to moisture absorption caused by EH and peeling of the interface between the lower electrode substrate 2 and the resin coat 7.8, a water film is generated between the different metal thin film wirings 1, resulting in corrosion of the metal thin film wiring 2 and electrochemical reaction during energization. This may cause disconnection or touch between lines due to metal deposits, making it impossible to display.

[Purpose of the invention]

An object of the present invention is to provide a liquid crystal display element with excellent moisture resistance and reliability in a high temperature environment.

[Summary of the invention]

In order to achieve the above objects, the present invention has the following features: (1) A liquid crystal display is produced by patterning metal thin film wiring on one substrate f constituting a liquid crystal display element, and directly connecting a semiconductor chip for driving a liquid crystal onto the metal thin film wiring. The element is characterized in that an inorganic film is formed as a protective film on the metal thin film wiring.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 2 and 3. A portion of the transparent conductive film 10 is coated with a NiCr film 12 that has good adhesion to glass, which is the material of this substrate 11, on a lower electrode substrate 11 on which a lighting pattern is patterned using a transparent conductive film 10.
A Cu film 13 having good wettability with solder is formed thereon, and a wiring pattern is formed by photo-etching to form a two-layer film wiring 14. Next, to cover the entire surface and side surfaces of the two-layer film wiring 14, 5102, SiN, k120. Inorganic membranes such as 15
is formed by a method such as vapor deposition, and a through hole is provided in the portion t to which the solder 16 is connected. Next, sealant 17
The upper electrode substrate 18 is fixed to the lower electrode substrate 11 via the upper electrode substrate 11, and a liquid crystal is sealed between the lower electrode substrate 11 and the upper electrode substrate 18 to assemble a liquid crystal cell. After that, the liquid crystal driving semiconductor chip 19 is soldered to the two-layer film wiring 14 via the solder 16 . The inorganic film 15 also functions as a solder dam that prevents the solder 16 from spreading through the Cu film 13, and makes the solder connection shape constant. Next, in order to protect the liquid crystal driving semiconductor chip 19 connected by soldering, a resin coat 20, which is usually used as a resin cage for semiconductor components, is formed.

In this way, since the inorganic film 15 with excellent moisture resistance is formed as a protective film for the metal thin film wiring (two-layer film wiring) 14 formed on the lower electrode substrate 11, it can be used in a high humidity environment. In this way, a chip-on liquid crystal display element having excellent moisture resistance and reliability can be obtained.

In addition, in order to further strengthen the moisture resistance, the two-layer film wiring 14
Instead of the Cu film 13 constituting the structure, an Au film, which is an electrochemically sensitive metal, may be used.

〔Effect of the invention〕

As is clear from the above description, according to the present invention f, one substrate l constituting a liquid crystal display element and metal thin film wiring are patterned, and a liquid crystal driving semiconductor chip is directly connected to the metal thin film wiring. In this chip-on liquid crystal display element f, since an inorganic film is formed as a protection film on the metal thin film wiring, a chip-on liquid crystal display element having excellent moisture resistance reliability in a high humidity environment can be obtained.

[Brief explanation of the drawing]

Figure 1 is a schematic cross-sectional view of a conventional chip-on liquid crystal display element.
FIG. 2 is a schematic cross-sectional view showing an embodiment of the chip-on liquid crystal display element according to the present invention, and FIG. 3 is an enlarged cross-sectional view of the connecting portion of the semiconductor chip for driving the liquid crystal shown in FIG. 11... Lower electrode substrate, 14... Two-layer film wiring, 15
...Inorganic film, 19...Semiconductor chip for liquid crystal drive. Figure 1 Figure 2 Figure 3 Figure 1) 11

Claims (1)

[Claims] In a chip-on liquid crystal display element in which a metal thin film wiring is patterned on one substrate constituting the liquid crystal display element and a liquid crystal driving semiconductor chip is directly connected to the metal thin film wiring, a protective layer is provided on the metal thin film wiring. A liquid crystal display element characterized by forming an inorganic film as a film.