JPH03209430A - Manufacture of liquid crystal display device - Google Patents

Abstract

PURPOSE:To prevent an active element from being destroyed by static electricity by cutting a short-circuited spot after connecting a driving circuit. CONSTITUTION:When the active element is formed on a lower substrate 10, an electrode 11 for connection, connecting terminal 12 and short-circuit terminal 13 are simultaneously formed. At such a time, the electrode 11 for connection and the connecting terminal 12 are simultaneously patterned and the electrode 11 for connection is arranged so as to be short-circuited at the short-circuit terminal 13. Afterwards, a liquid crystal cell assembly process is executed and finally, the rear surface of the lower substrate 10 is irradiated with a laser beam to cut the short-circuit terminal 13. Thus, the active element is prevented from being destroyed by the static electricity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an active liquid crystal display device having a large number of pixels, which is used in display panels of measuring instruments, computer image display devices, televisions, and the like.

[Summary of the invention]

The present invention provides a method for manufacturing a matrix structure liquid crystal display device in which a drive circuit is connected to a transparent substrate on which active elements are formed to drive a liquid crystal, in which connection terminals for connecting the drive circuit are formed by short-circuiting. After the drive circuit is connected, a laser beam is irradiated from the back side of the board to cut the short circuit, thereby preventing damage to the active elements due to static electricity.

[Prior art]

Until now, a method of driving a liquid crystal by directly connecting a driving circuit on a transparent substrate is generally known as COG (chip on glass). On the other hand, liquid crystal display devices using active elements are susceptible to static electricity, especially during the liquid crystal cell assembly process.
It is known that static electricity is generated during the rubbing process and deflection plate attachment process, which can destroy active elements. For this reason, a method of short-circuiting the connecting terminals in order to prevent damage caused by static electricity has been proposed in Japanese Patent Laid-Open No. 1-230020.

[Problem to be solved by the invention]

However, in the conventional method, it is necessary to disconnect the short-circuited portion before connecting the drive circuit, and damage to the active element due to static electricity cannot be prevented during the process from disconnection to connection of the drive circuit.

Therefore, the present invention prevents active elements from being destroyed by static electricity by disconnecting the short circuit after connecting the drive circuit using the COG method.

[Means to solve the problem]

In order to solve the above problems, the present invention creates a short circuit when forming connection electrodes for connecting the drive circuit, and after connecting the drive circuit, cuts the short point using a laser beam from the back surface of the transparent substrate. do.

[Effect]

In the method for manufacturing a liquid crystal display device configured as described above,
Since the connection electrodes are short-circuited until the drive circuit is connected, active elements are not destroyed by static electricity, and pixel defects in liquid crystal display devices are less likely to occur.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1(a) shows a plan view of a liquid crystal display device according to the present invention. Here, active elements and the like are omitted to simplify the explanation. FIG. 1(b) shows a cross-sectional view of FIG. 1(a). Here, the deflection plate, alignment film, etc. are omitted for the sake of simplicity.

FIG. 2 is an enlarged view of section A in FIG. 1(a).

FIGS. 3(a) to 3(C) are longitudinal cross-sectional views showing each step of the method for manufacturing a liquid crystal display device according to the present invention.

In FIGS. 1(a) and 1(b), 1 is a lower substrate made of transparent glass, and active elements are formed on the lower substrate 1. In FIG. The active element is a three-terminal element TFT (
Thin film (Run sister) and diodes which are two-terminal elements are known. The active element is provided with a source electrode, a gate electrode, etc. for applying a signal waveform, and is wired by a connection electrode 3. Drive circuit 4
is attached via a connection terminal 5 formed on the connection electrode 3, and supplies a signal waveform to the active element.

2 is an upper substrate made of the same material as the lower substrate 1. Liquid crystal 6 is sandwiched between lower substrate 1 and upper substrate 2.

Next, a method for manufacturing a liquid crystal display device according to the present invention will be explained with reference to FIG. 2 and FIGS. 3(a) to 3(C).

FIG. 2 is an enlarged view of section A in FIG. 1(a).

FIGS. 3(a) to 3(C) are longitudinal cross-sectional views showing each step of the method for manufacturing a liquid crystal display device according to the present invention.

When forming the active element on the lower substrate 1, the connection electrode 11, the connection terminal 12, and the short terminal 13 are formed at the same time (FIG. 3(a)). Generally, tantalum, molybdenum, chromium, aluminum, or the like is deposited on the electrodes of the active element by sputtering or the like, and patterned into an arbitrary shape by a photoetching process. At this time, the connection electrode 11 and the connection terminal 12 are patterned at the same time, and the connection electrode 11 is arranged so as to be short-circuited at the short terminal 13 (Fig. 2).
The L connection terminal 12 does not necessarily have to be made of the same material as the electrode of the active element, and may be made of another metal material. For example, a transparent conductive film made of ITO electroless plated with nickel or plated with gold may be considered.

After that, the liquid crystal cell assembly process is performed.In the liquid crystal cell assembly process, the rubbing process and the installation of the deflection plate are performed.
Although there are many processes in which static electricity is generated, the connection electrode 11 is short-circuited with the short terminal 13, so even if static electricity is generated, it is not concentrated in one place but is dispersed, so that it does not damage the active element. It disappears.

After that, the drive circuit 14 is attached onto the connection terminal 12 (
Figure 3(b)). The connection method is performed by soldering or the like.

Finally, laser light is irradiated from the back surface of the lower substrate 10 to cut the short terminals 13 and complete the process (Fig. 3(C)).
). Therefore, since the connection electrodes remain short-circuited until the liquid crystal display device is completed, destruction of the active elements due to static electricity can be prevented.

[Effects of the Invention] As described above, the present invention provides a method for manufacturing a liquid crystal display device using an active element, in which the connecting electrodes are short-circuited until just before the liquid crystal display device is completed (thereby preventing static electricity from forming). By eliminating the destruction of active elements, we were able to create a liquid crystal display device with no pixel defects.

[Brief explanation of drawings]

FIG. 1(a) shows a plan view of an embodiment of a liquid crystal display device according to the present invention. Figure 1(b) is the same as Figure 1(b).
Fig. 3b shows a cross-sectional view of a). FIG. 2 is an enlarged view of section A in FIG. 1(a). FIGS. 3(a) to 3(C) are longitudinal cross-sectional views showing each step of the method for manufacturing a liquid crystal display device according to the present invention. Lower board...1.10 Upper board...2 Connection electrode...3.11 Drive circuit...4.14 Connection terminal...5.12 Liquid crystal...・・6 Short terminal・・13 or more

Claims (1)

[Claims] (1) Two opposing transparent substrates, a liquid crystal layer sandwiched between the substrates, a large number of row electrode groups formed on the inner surface of one substrate, and a large number of column electrodes formed on the inner surface of the other substrate. Each pixel on at least one substrate is composed of a pixel electrode and an active element, and a drive circuit for driving the active element is connected via a connection electrode formed on the substrate. A method for manufacturing a liquid crystal display device comprising the steps of shorting and forming the connection electrodes, connecting the drive circuit, and cutting the short portion of the connection electrodes with a laser beam or the like. A method for manufacturing a liquid crystal display device.