JPH11337979A - Manufacture of liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a destruction of active elements constituting a liquid crystal display due to an electrostatic charge in a manufacturing process. SOLUTION: When a metal constituting TFD element 3 is going to be patterned after signal lines 2, IC output terminals 6 and IC input terminals 7 are patterned on a base material of a device side substrate 1, simultaneously an annular conductive pattern 19 is patterned to make a plurality of IC output terminals 6 and a plurality of IC input terminals 7 mutually conductive and to keep them at the same potential. A counter side substrate is stuck with the device side substrate 1, liquid crystal is enclosed in it, individual liquid crystal panels are segmented by scribing it along with scribe lines L1 -L4 and subsequently the conductive pattern 19 is removed by etching. In the period when the conductive pattern 19 is present, even if arm electrostatic charge streams along each of the signal lines 2, the destruction of TFD element 3 is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal device that modulates light passing through a liquid crystal by controlling the voltage applied to the liquid crystal and controlling the orientation of the liquid crystal, and more particularly to manufacturing the liquid crystal device. For a manufacturing method.

[0002]

2. Description of the Related Art It is widely known that liquid crystal devices include an active matrix system and a simple matrix system. In an active matrix type liquid crystal device, a TFT (Thin Film Transistor) element or a TFD (Thin Film Transistor) is used.
An active element such as an in-film diode element is provided for each pixel. On the other hand, in a simple matrix type liquid crystal device, each pixel is formed in a dot matrix at the intersection of a scanning electrode and a data electrode without providing an active element for each pixel.

Now, consider a liquid crystal device using a TFD element as an active matrix type liquid crystal device. For example, the liquid crystal device includes, for example, an element-side substrate base material in which a TFD element and a pixel electrode are formed in a dot matrix, A plurality of opposing electrodes are formed in parallel with each other with a sealing material, and a liquid crystal is sealed between the substrate materials. The substrate base material is cut to cut out a plurality of liquid crystal panels for one liquid crystal device.

Various patterns can be considered for the wiring pattern formed on the element substrate base material in connection with the mounting method of the liquid crystal driving IC. For example, a COG (Chip On Gl
Considering the mounting structure of the (ass) system, a wiring pattern as shown in FIG. 7 can be considered as an example. In the figure, a plurality of linear signal lines 52 are formed on an element-side substrate base material 51 in parallel with each other, and TFD elements 53 are formed on the signal lines 52 at predetermined intervals. A pixel electrode 54 is formed for each of the 53.

The pixel electrode 54, the TFD element 53, and the like are actually very small and a large number of dots, which are difficult to recognize with the naked eye. However, in FIG. The electrodes 54 and the like are schematically shown in an enlarged manner, and the arrangement intervals of the signal lines 52 are also schematically shown in an enlarged manner. Further, a part of the plurality of pixel electrodes 54 and the like is omitted, and the part is indicated by a chain line. Further, the wiring pattern shown in FIG. 7 is a wiring pattern corresponding to one liquid crystal device, and a plurality of wiring patterns shown in FIG. Since those wiring patterns are all the same pattern, FIG. 7 shows one of those wiring patterns.

An IC mounting area A for mounting a liquid crystal driving IC is set at an appropriate position on the element-side substrate base material 51, and an IC output terminal 56 extending from each signal line 52.
Are arranged in a row on the side of the IC mounting area A. Further, the tips of the IC input terminals 57 are arranged in a row on the other side of the IC mounting area A. LCD drive IC
When bonded to the C mounting area A, the input bump of the liquid crystal driving IC is conductively connected to the tip of the IC input terminal 57, and the output bump of the liquid crystal driving IC is conductively connected to the tip of the IC output terminal 56.

[0007]

By the way, a cutting step, that is, a breaking step and other various steps are performed on the element-side substrate base material 51 shown in FIG. 7, and static electricity is generated during these steps. Sometimes. In this case, there is a possibility that the TFD element 53 may be broken due to static electricity flowing through a part of the plurality of signal lines 52. Especially,
In the element side substrate preform 51 of the COG type as shown in FIG. 7, the pattern between the IC output terminal 56 and the IC input terminal 57 is cut off, so that static electricity easily flows between them. Therefore, element destruction due to static electricity is likely to occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems in a conventional method of manufacturing a liquid crystal device, and has an object to prevent an active element constituting a liquid crystal device from being destroyed by static electricity. I do.

[0009]

(1) In order to achieve the above object, in a method of manufacturing a liquid crystal device according to the present invention, a plurality of signal lines are formed on an element-side substrate base material on which active elements are formed. A signal line forming step, a conductive pattern forming step of forming a conductive pattern for electrically connecting the plurality of signal lines to each other in an externally exposed region of the element side substrate base material, and a side facing the element side substrate base material. A step of bonding the substrate base material, and a breaking step of cutting the bonded element-side substrate base material and the opposed-side substrate base material into individual liquid crystal device portions, and simultaneously exposing the externally exposed region to the outside. A conductive pattern for removing the conductive pattern formed in the externally exposed region by performing an etching process on the externally exposed region which has been exposed to the outside by the breaking step. And a turn removing step.

According to this method of manufacturing a liquid crystal device, a plurality of signal lines formed on the element-side substrate base material are made conductive by the conductive pattern and are kept at the same potential. In this step, no static electricity is generated on the element-side substrate base material, and thus, it is possible to prevent the active element provided on the signal line from being broken by the static electricity.

In particular, according to the present invention, a conductive pattern is present to prevent the generation of static electricity until the breaking step, which is considered to be most likely to generate static electricity, is completed, and the conductive pattern is removed after the breaking step is completed. So
Destruction of the element due to static electricity can be almost completely prevented.

In the above configuration, the "active element"
Examples thereof include a TFT (Thin Film Transistor) element and a TFD (Thin Film Diode) element.
The “element-side substrate base material” is a large-area substrate having a plurality of element-side wiring patterns for one liquid crystal device. The “signal line” sometimes acts as a data line for selecting a specific pixel, and sometimes acts as a scanning line for selecting a plurality of pixels for each column.

(2) In the above-mentioned method of manufacturing a liquid crystal device, the conductive pattern can be simultaneously patterned by using the same material when patterning the metal constituting the active element. In this case, there is no need to provide a special process for forming the conductive pattern.

As an active element, a TFD (Thin Fil) having a laminated structure of a first electrode, an insulating film and a second electrode is used.
In the case of using an m-diode element, the conductive pattern can be simultaneously patterned with the same material when patterning the first electrode or the second electrode. In this case, for example, Ta (tantalum) can be used as the first electrode, while, for example, Cr (chromium) can be used as the second electrode.

(3) The method of manufacturing a liquid crystal device according to the above (1) or (2), wherein the IC of the element side substrate for one liquid crystal device formed by cutting a large area element side substrate base material is formed. The present invention can be applied to a liquid crystal device having a structure in which a liquid crystal driving IC is directly mounted on a mounting region, that is, a so-called COG (Chip On Glass) liquid crystal device.

In this case, in the signal line forming step, a plurality of IC output terminals extending from each of the plurality of signal lines and a plurality of ICs connected to input pads of the liquid crystal driving IC are provided.
A C input terminal is formed. Then, in the conductive pattern forming step, the plurality of IC output terminals and the plurality of I
An annular conductive pattern that allows all of the C input terminals to conduct with each other can be formed.

Thus, when no measures are taken, the IC output terminal and the IC input terminal, which are patterns cut off from each other, can be made conductive to keep them at the same potential, whereby static electricity flows as a large current. Thus, it is possible to prevent the active element from being destroyed.

(4) When the annular conductive pattern is formed as described above, the conductive pattern can be formed outside the IC mounting area.

(5) If the conductive pattern is formed outside the IC mounting area as described above, after the liquid crystal driving IC is mounted on the IC mounting area, the conductive pattern existing outside the IC mounting area is removed by etching. it can. In this case, a step of mounting the liquid crystal driving IC on the element side substrate,
That is, it is possible to prevent the destruction of the element due to static electricity in the IC mounting process.

(6) When the conductive pattern is removed by etching after mounting the liquid crystal driving IC as in the above (5), the liquid crystal driving IC mounted on the element side substrate is removed by a conductive pattern removing step. It is desirable to cover with a mold before performing. This can prevent the liquid crystal driving IC from being adversely affected by the etching process for removing the conductive pattern. In particular, when the etching process is wet etching, it is particularly effective to mold the liquid crystal driving IC.

[0021]

FIG. 5 shows an example of a liquid crystal device which can be manufactured by using the manufacturing method according to the present invention. In this liquid crystal device, a liquid crystal panel formed by bonding an element-side substrate 1a and a counter-side substrate 8a to each other with a sealing material 9 and enclosing a liquid crystal L between the substrates 1a and 8a has a liquid crystal driving device. IC12 is mounted, and each substrate 1a is further mounted.
And 8a are formed by attaching polarizing plates 13, 13 to the outer surfaces.

An IC mounting area A is set in an externally exposed area 1b of the element side substrate 1a which is exposed to the outside of the opposing side substrate 8a. Also, of the opposing substrate 8a, the element-side substrate 1a
The IC mounting area A is also provided in the externally exposed area 8b exposed to the outside of the
Is set. The liquid crystal driving IC 12 is an ACF (Anisot
Using a ropic conductive film (anisotropic conductive film) 11, these are bonded to the IC mounting areas A.

Hereinafter, a manufacturing method for manufacturing the above-described liquid crystal device will be described. First, in FIG. 1, a large-area element-side substrate base material 1 formed of a glass substrate, a plastic substrate, or the like is prepared. This element-side substrate preform 1
Although the substrate base material has a large area for forming a wiring pattern for an element-side substrate for a plurality of liquid crystal panels, FIG. 1 shows only a region near the wiring pattern for one liquid crystal panel.

On the prepared element-side substrate preform 1, Ta ₂ O ₅ is formed as a base layer as in step S1 of FIG. Thereby, the underlayer 21 is formed with a uniform thickness on the surface of the element-side substrate base material 1 in FIG. Next, in FIG. 1, the signal lines 2,
A large number of IC output terminals 6 and IC input terminals 7 integrated therewith are formed (step S2 in FIG. 6).

As shown in FIG. 3, simultaneously with forming the signal line 2, the first electrode 14 for the TFD element 3 is formed (Step S2 in FIG. 6). As shown in FIG. 1, at the same time when the signal lines 2 and the like are formed, the common wiring 16a to which the plurality of signal lines 2 are connected and the plurality of IC input terminals 7 are connected.
Are formed simultaneously by Ta.

Thereafter, an anode voltage is applied to the common wires 16a and 16b while the element-side substrate preform 1 is immersed in an anodizing treatment solution (chemical conversion solution) to apply a signal line 2, an IC output terminal 6, An anodic oxide film is formed on each pattern of the IC input terminal 7 and the first electrode 14 (see FIG. 3) (Step S3 in FIG. 6). Thus, the insulating film 17 is formed on the first electrode 14 in FIG.

Thereafter, in FIG. 3, Cr is patterned on the insulating film 17 to form a second electrode 18, and at the same time, in FIG.
Is similarly patterned with Cr (Step S4 in FIG. 6). By patterning the second electrode 18 on the insulating film 17, the first electrode 14, the insulating film 17 and the second
The TFD element 3 having a laminated structure of the electrodes 18 is formed. 2, the conductive pattern 19 electrically connects all of the plurality of IC output terminals 6 and the plurality of IC input terminals 7 to each other. All of the terminals 7 are held at the same potential, that is, such that no potential difference occurs.

Thereafter, in FIG. 3, ITO (Indium Tin Oxide) is patterned on the underlayer 21 to form the pixel electrode 4 (Step S5 in FIG. 6). The corner of the pixel electrode 4 overlaps the tip of the second electrode 18 constituting the TFD element 3. Next, an alignment film is formed on the surface of the element-side substrate base material 1 (step S6 in FIG. 6), and an alignment process, for example, a rubbing process is performed (step S7). An annular sealing material 9 is formed (Step S8). The sealing material 9 is formed of, for example, a thermosetting resin, and all the pixel electrodes 4 formed in a dot matrix shape are formed.
Are arranged to surround the.

While the element-side substrate preform 1 is manufactured as described above, the opposing-side substrate preform 8 as shown in FIG. 4 is manufactured as in steps S9 to S12 in FIG. Specifically, first, an opposing substrate base material 8 having a large area formed of a glass substrate, a plastic substrate, or the like is prepared. The opposing substrate preform 8 is a substrate preform for forming a wiring pattern for the opposing substrate for a plurality of liquid crystal panels. In FIG. 4, only the area near the wiring pattern for one liquid crystal panel is used. Is shown.

In FIG. 4, the prepared opposing substrate base material 8 is prepared.
A color filter 23 is formed on the surface (step S9 of FIG. 6), and a linear counter electrode 24 is formed by ITO.
Are formed in parallel with each other, and at the same time, an IC output terminal 26 and an IC input terminal 27 are formed (Step S10 in FIG. 6). Next, an alignment film is formed on the surface of the opposite-side substrate base material 8 (Step S11 in FIG. 6), and an alignment process, for example, a rubbing process is performed on the alignment film (Step S12 in FIG. 6). Thereby, the opposing substrate preform 8 is completed.

Thereafter, the element-side substrate preform 1 (FIG. 1) and the opposing-side substrate preform 8 (FIG. 4) manufactured as described above are adhered to each other with a sealing material 9 (FIG. 1) interposed therebetween. Together, a panel base material is formed (step S13 in FIG. 6), and then the panel base material is heated to cure the sealing material 9 (FIG. 6).
Step S14). Next, a liquid crystal is injected into a portion surrounded by the sealing material 9 through a liquid crystal injection port (not shown) formed at an appropriate position of the sealing material 9, and the liquid crystal injection port is further sealed (step S15 in FIG. 6). . If all of the liquid crystal injection ports of the plurality of liquid crystal panels included in the panel base material are not exposed to the outside, a cutting process of the panel base material, that is, a so-called break process is performed as necessary. The liquid crystal injection port of the liquid crystal panel is exposed to the outside.

Thereafter, a break process is performed in step S16 of FIG. Specifically, in FIG. 1, straight grooves for cutting, so-called scribe lines L1, L2, L3, L4 are formed on the element-side substrate base material 1, and in FIG. Line L5, L
6, L7 and L8 are formed. Then, with respect to each scribe line, the substrate on the opposite side is hit or pressed to cut each of the substrate base materials 1 and 8 based on the scribe lines, whereby a plurality of liquid crystal panels as shown in FIG. It is made. At this time, the liquid crystal driving IC 12
Is not implemented.

When each of the above steps is performed, static electricity is generated on the element-side substrate base material 1 (FIG. 1), which may flow through each signal line 2. In particular, such static electricity is likely to be generated in the break process (step 16 in FIG. 6). However, in the present embodiment, since the conductive pattern 19 is formed in step S4 and the plurality of IC output terminals 6 and thus the signal electrode 2 and the plurality of IC input terminals 7 are electrically connected to each other, a potential difference may occur between these elements. There is no.
As a result, it is possible to reliably prevent the TFD element 3 from being broken by static electricity flowing through each signal line 2.

Thereafter, in step S17 of FIG.
A conductive pattern removing step is performed to remove the conductive pattern 19 shown in FIG. Specifically, conductive pattern 1
9 is prepared, and in this embodiment, an etchant capable of etching Cr is prepared, and a region of the liquid crystal panel where the conductive pattern 19 is formed is immersed in the etchant. Thereby, the conductive pattern 19 is removed from the element-side substrate 1a. As a result, each IC output terminal 6, that is, each signal line 2 and each IC input terminal 7 are electrically independent from each other, and as a result, each signal line 2 can function as a data line or a scanning line.

Thereafter, in FIG. 5, a liquid crystal driving IC 12 is adhered to the IC mounting area A of the element-side substrate 1a and the counter-side substrate 8a using an ACF 11, and a polarizing plate 13 is attached to the outer surfaces of the substrates 1a and 8a. , 13 are attached to complete the liquid crystal device. At this time, the liquid crystal driving IC
Twelve input bumps, that is, input terminals, are conductively connected to the land at the tip of the IC input terminal 7.
The two output bumps or output terminals are conductively connected to the land at the tip of the IC output terminal 6. A lighting device such as a backlight is additionally provided outside one of the element-side substrate 1a and the opposite-side substrate 8a, if necessary.

In the above description, the liquid crystal driving IC 1
The conductive pattern 19 was removed by etching before bonding 2 to the element-side substrate 1a using ACF11. However, instead of this processing method, after the liquid crystal driving IC 12 is mounted, the conductive pattern 19 may be removed by an etching process that does not adversely affect the liquid crystal driving IC 12.

According to this method, since the conductive pattern 19 is also present at the time of mounting the liquid crystal driving IC 12, the device can be prevented from being damaged by static electricity even during the mounting operation. When the etching for removing the conductive pattern 19 is performed after the mounting of the liquid crystal driving IC 12, the liquid crystal driving IC 12 is desirably covered with a resin mold to shield it from the etching operation.

As described above, the present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the embodiments, and can be variously modified within the scope of the invention described in the claims. For example, in the above embodiment, the present invention is applied to a liquid crystal device using a TFD element. However, it is needless to say that the present invention can be applied to a liquid crystal device using a TFT element instead of the TFD element.

[0039]

According to the method of manufacturing a liquid crystal device according to the present invention, a plurality of signal lines connected to an active element such as a TFD element are prevented from conducting by a conductive pattern to cause a potential difference therebetween. It is possible to prevent the active elements constituting the liquid crystal device from being destroyed by static electricity during the manufacturing process of the liquid crystal device in various steps after the formation of the liquid crystal device.

[Brief description of the drawings]

FIG. 1 is a plan view showing a substrate structure manufactured in the middle of a method of manufacturing a liquid crystal device according to the present invention, in particular, a region for one liquid crystal panel of an element-side substrate base material.

FIG. 2 is an enlarged view showing a portion X in FIG. 1;

FIG. 3 is a perspective view showing an example of an active element and a structure around the active element.

FIG. 4 is a plan view showing a substrate structure produced in the course of the method of manufacturing a liquid crystal device according to the present invention, in particular, a region of one liquid crystal panel of a base material of the opposite substrate.

FIG. 5 is a perspective view illustrating an example of a liquid crystal device manufactured by the method for manufacturing a liquid crystal device according to the present invention.

FIG. 6 is a flowchart illustrating an embodiment of a method for manufacturing a liquid crystal device according to the present invention.

FIG. 7 is a plan view showing an example of an element-side substrate base material manufactured in the course of manufacturing a liquid crystal device using a conventional method for manufacturing a liquid crystal device.

[Description of Signs] 1 Element-side substrate base material 1a Element-side substrate 1b Externally exposed area 2 Signal line 3 TFD element (active element) 4 Pixel electrode 6 IC output terminal 7 IC input terminal 8 Opposite substrate preform 8a Opposite substrate 8b Externally exposed area 9 Sealing material 11 ACF 12 Liquid crystal driving IC 13 Polarizing plate 14 First electrode 16a, 16b common wiring 17 TFD element insulating film 18 TFD element insulating film 18 Second electrode of TFD element 19 Conductive pattern 21 Underlayer 23 Color Filter 24 Counter electrode 26 IC output terminal 27 IC input terminal A IC mounting area L Liquid crystal L1 to L8 Scribe line

Claims (6)

[Claims] 1. A signal line forming step of forming a plurality of signal lines on an element-side substrate base material on which an active element is formed; and a conductive pattern for electrically connecting the plurality of signal lines to each other. Forming a conductive pattern in an externally exposed region of the above, bonding the element-side substrate base material and the opposing-side substrate preform, and bonding the element-side substrate preform and the opposing-side substrate preform Is cut into individual liquid crystal device portions, and at the same time, a breaking step of exposing the externally exposed area to the outside, and performing an etching treatment on the externally exposed area that has been exposed to the outside by the breaking step, A conductive pattern removing step of removing the conductive pattern formed in the externally exposed region. 2. The method for manufacturing a liquid crystal device according to claim 1, wherein said conductive pattern is simultaneously patterned with the same material when patterning a metal constituting said active element. Method. 3. The method of manufacturing a liquid crystal device according to claim 1, wherein said liquid crystal device is formed by cutting said element-side substrate base material. A liquid crystal device having a structure in which a liquid crystal driving IC is directly mounted on an IC mounting area. In the signal line forming step, a plurality of IC output terminals extending from each of the plurality of signal lines and an input terminal of the liquid crystal driving IC are provided. A plurality of IC input terminals connected to the plurality of IC input terminals are formed; and in the conductive pattern forming step, an annular conductive pattern for electrically connecting all of the plurality of IC output terminals and the plurality of IC input terminals to each other is formed. Of manufacturing a liquid crystal device. 4. The method for manufacturing a liquid crystal device according to claim 3, wherein the annular conductive pattern is formed outside the IC mounting area. 5. The method of manufacturing a liquid crystal device according to claim 3, wherein the conductive pattern removing step is performed after the liquid crystal driving IC is mounted on the element-side substrate. A method for manufacturing a liquid crystal device. 6. The method for manufacturing a liquid crystal device according to claim 5, wherein the liquid crystal driving IC mounted on the element-side substrate.
Is covered with a mold before performing the conductive pattern removing step.