JP3726493B2 - Manufacturing method of liquid crystal device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a liquid crystal device that modulates light passing through the liquid crystal by controlling the voltage applied to the liquid crystal to control the alignment of the liquid crystal, and more particularly to a manufacturing method for manufacturing the liquid crystal device.
[0002]
[Prior art]
It is widely known that liquid crystal devices include an active matrix method and a simple matrix method. In an active matrix liquid crystal device, an active element such as a thin film transistor (TFT) element or a thin film diode (TFD) 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 by an intersection of a scanning electrode and a data electrode without providing an active element for each pixel.
[0003]
Considering a liquid crystal device using a TFD element as an active matrix type liquid crystal device, the liquid crystal device is, for example, an element side substrate base material in which a TFD element and a pixel electrode are formed in a dot matrix shape, and a linear opposed A plurality of electrodes formed in parallel with each other are bonded to each other with a sealing material, and liquid crystal is sealed between the substrate base materials. After that, the element side substrate base material and the counter side substrate base material And a plurality of liquid crystal panels for one liquid crystal device are cut out.
[0004]
As the wiring pattern formed on the element substrate base material, various patterns can be considered in relation to the mounting method of the liquid crystal driving IC. For example, if a COG (Chip On Glass) mounting structure is considered, A wiring pattern as shown in FIG. 7 is considered as an example. In the figure, a plurality of linear signal lines 52 are formed in parallel to each other on the element-side substrate base material 51, TFD elements 53 are formed on these signal lines 52 at predetermined intervals, and these TFD elements are further formed. A pixel electrode 54 is formed in each of 53.
[0005]
The pixel electrode 54, the TFD element 53, and the like are actually very small and a large number of dots that are difficult to recognize with the naked eye. However, in FIG. Is enlarged and schematically shown, and the arrangement interval of the signal lines 52 is also enlarged and shown schematically. Further, a part of the plurality of pixel electrodes 54 and the like is omitted, and the part is indicated by a chain line. 7 is a wiring pattern corresponding to one liquid crystal device, and a plurality of wiring patterns shown in FIG. 7 are formed on the surface of the element-side substrate base material 51. The wiring pattern shown in FIG. Since these wiring patterns are all the same pattern, FIG. 7 shows one of those wiring patterns.
[0006]
An IC mounting area A, which is an area for mounting a liquid crystal driving IC, is set at an appropriate position on the element side substrate base material 51, and the tip of the IC output terminal 56 extending from each signal line 52 is the IC mounting area A. It is arranged in a row on the side part. Further, the tips of the IC input terminals 57 are arranged in a row on the other side of the IC mounting area A. When the liquid crystal driving IC is bonded to the IC 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 conductive to the tip of the IC output terminal 56. Connecting.
[0007]
[Problems to be solved by the invention]
Incidentally, a cutting process, that is, a breaking process and other various processes are performed on the element-side substrate base material 51 shown in FIG. 7, and static electricity may be generated during these processes. In that case, the TFD element 53 may be destroyed due to static electricity flowing through some of the signal lines 52. In particular, with respect to the element side substrate base material 51 of the COG method 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 easily occurs.
[0008]
The present invention has been made in view of the above-described problems in the conventional method of manufacturing a liquid crystal device, and an object thereof is to prevent an active element constituting the liquid crystal device from being destroyed by static electricity.
[0009]
[Means for Solving the Problems]
(1) In order to achieve the above object, a method of manufacturing a liquid crystal device according to the present invention includes 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, A conductive pattern forming step for forming a conductive pattern for electrically connecting the signal lines to each other except for a tip portion of the plurality of signal lines extending to an externally exposed region of the element side substrate base material; and Bonding the element-side substrate base material and the counter-side substrate base material, cutting the bonded element-side substrate base material and the counter-side substrate base material into individual liquid crystal device parts, and simultaneously performing the external exposure The step that was formed in the externally exposed region by performing an etching process on the externally exposed region that has been exposed to the outside by the break step, and the breaking step that exposes the region to the outside And a conductive pattern removing step for removing the conductive pattern.
[0010]
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 held at the same potential. Therefore, in various processes performed after the formation of the conductive pattern Static electricity is not generated in the element side substrate base material, and therefore, it is possible to prevent the active element provided in the signal line from being broken by static electricity.
[0011]
In particular, in the present invention, until the break process, which is considered to be most likely to generate static electricity, is completed, the conductive pattern is present to prevent the generation of static electricity, and the conductive pattern is removed after the break process is completed. The destruction of the element due to static electricity can be almost completely prevented.
[0012]
In the above configuration, examples of the “active element” include a TFT (Thin Film Transistor) element and a TFD (Thin Film Diode) element. The “element-side substrate base material” refers to a large-area substrate having a plurality of element-side wiring patterns for one liquid crystal device. The “signal line” functions as a data line for selecting a specific pixel in some cases, and also functions as a scanning line for selecting a plurality of pixels for each column.
[0013]
(2) In the method for manufacturing a liquid crystal device, the conductive pattern can be simultaneously patterned with the same material when the metal constituting the active element is patterned. In this case, there is no need to provide a special process for forming the conductive pattern, so there is no concern that the manufacturing cost will increase.
[0014]
In the case where a TFD (Thin Film Diode) element having a laminated structure of a first electrode, an insulating film, and a second electrode is used as an active element, the same material as that used for patterning the first electrode or the second electrode is used. Thus, the conductive pattern can be patterned simultaneously. 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.
[0015]
(3) In the method for manufacturing a liquid crystal device according to (1) or (2), an IC mounting region of an element side substrate for one liquid crystal device formed by cutting a large area element side substrate base material is provided. The present invention can be applied to a liquid crystal device having a structure in which a liquid crystal driving IC is directly mounted, that is, a so-called COG (Chip On Glass) type liquid crystal device.
[0016]
In that case, a signal line forming step for forming a plurality of signal lines on the element side substrate base material on which the active element is formed, and a conductive pattern for electrically connecting the plurality of signal lines to each other are included in the element side substrate base material. A conductive pattern forming step formed in an externally exposed region of the substrate, a step of bonding the element-side substrate base material and the counter-side substrate base material, and the bonded element-side substrate base material and the counter-side substrate base material individually Cutting the liquid crystal device portion and simultaneously exposing the externally exposed region to the outside, and performing an etching process on the externally exposed region that has been exposed to the outside by the breaking step. A conductive pattern removing step of removing the conductive pattern formed in the exposed region, wherein the signal line forming step includes: A plurality of IC output terminals and said extending from each of the plurality of IC input terminal connected to an input pad of the liquid crystal driving IC is formed. In the conductive pattern forming step, an annular conductive pattern that connects all of the plurality of IC output terminals and the plurality of IC input terminals to each other can be formed.
[0017]
As a result, when no measures are taken, the IC output terminal and the IC input terminal, which are mutually disconnected patterns, can be made conductive and held at the same potential. Can be prevented from being destroyed.
[0018]
(4) When the annular conductive pattern is formed as described above, the conductive pattern can be formed outside the IC mounting region.
[0019]
(5) If the conductive pattern is formed outside the IC mounting region as described above, the conductive pattern existing outside the IC mounting region can be removed by etching after the liquid crystal driving IC is mounted. In this way, it is possible to prevent the element from being destroyed by static electricity in the process of mounting the liquid crystal driving IC on the element side substrate, that is, the IC mounting process.
[0020]
(6) When the conductive pattern is removed by etching after mounting the liquid crystal driving IC as in (5) above, the conductive pattern removing step is performed on the liquid crystal driving IC mounted on the element side substrate. It is desirable to cover with a mold before. In this way, it is possible to 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 a liquid crystal driving IC.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 5 shows an example of a liquid crystal device that can be manufactured using the manufacturing method according to the present invention. In this liquid crystal device, an element side substrate 1a and a counter side substrate 8a are bonded to each other by a sealing material 9, and liquid crystal L is sealed between the substrates 1a and 8a. It is formed by mounting the IC 12 and further attaching polarizing plates 13 and 13 to the outer surfaces of the substrates 1a and 8a.
[0022]
An IC mounting area A is set in the external exposure area 1b exposed to the outside of the counter-side board 8a in the element side board 1a. The IC mounting area A is also set in the external exposed area 8b exposed to the outside of the element-side board 1a in the counter-side board 8a. The liquid crystal driving ICs 12 are bonded to their IC mounting areas A using an ACF (Anisotropic Conductive Film) 11.
[0023]
Hereinafter, a manufacturing method for manufacturing the 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. The element side substrate base material 1 is a substrate base material having a large area for forming wiring patterns for element side substrates for a plurality of liquid crystal panels. In FIG. Only the area is shown.
[0024]
A Ta ₂ O ₅ film is formed on the prepared element-side substrate base material 1 as a base layer as in step S1 of FIG. Thereby, in FIG. 3, the base layer 21 is formed with a uniform thickness on the surface of the element-side substrate base material 1. Next, in FIG. 1, a signal line 2 and a large number of IC output terminals 6 and IC input terminals 7 integrated therewith are formed on the base layer 21 by Ta (step S2 in FIG. 6).
[0025]
Also, as shown in FIG. 3, the first electrode 14 for the TFD element 3 is formed simultaneously with the formation of the signal line 2 (step S2 in FIG. 6). As shown in FIG. 1, simultaneously with the formation of the signal line 2 and the like, the common wiring 16a to which the plurality of signal lines 2 are connected and the common wiring 16b to which the plurality of IC input terminals 7 are connected are simultaneously formed by Ta. Is done.
[0026]
Thereafter, an anode voltage is applied to the common wirings 16a and 16b in a state where the element side substrate base material 1 is immersed in an anodic oxidation treatment liquid (chemical conversion liquid), and the signal line 2, the IC output terminal 6, and the IC input terminal. An anodic oxide film is formed on each pattern of 7 and the first electrode 14 (see FIG. 3) (step S3 in FIG. 6). As a result, the insulating film 17 is formed on the first electrode 14 in FIG.
[0027]
Thereafter, in FIG. 3, Cr is patterned on the insulating film 17 to form the second electrode 18, and at the same time, in FIG. 1, a rectangular and annular conductive pattern 19 is similarly patterned with Cr (step S4 in FIG. 6). ). By patterning the second electrode 18 on the insulating film 17, the TFD element 3 having a laminated structure of the first electrode 14, the insulating film 17 and the second electrode 18 is formed. As shown in FIG. 2, the conductive pattern 19 electrically connects all of the plurality of IC output terminals 6 and the plurality of IC input terminals 7, and the conductive pattern 19 allows the IC output terminal 6 and the IC input to be connected. All of the terminals 7 are held at the same potential, that is, so as not to cause a potential difference.
[0028]
Thereafter, in FIG. 3, ITO (Indium Tin Oxide) is patterned on the base layer 21 to form the pixel electrode 4 (step S <b> 5 in FIG. 6). The corner portion of the pixel electrode 4 overlaps the tip portion 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), further subjected to an alignment process such as a rubbing process (step S7), and further, for example, as shown in FIG. An annular sealing material 9 is formed (step S8). The sealing material 9 is made of, for example, a thermosetting resin, and is disposed so as to surround all the pixel electrodes 4 formed in a dot matrix shape.
[0029]
While the element side substrate base material 1 is manufactured as described above, the opposite side substrate base material 8 as shown in FIG. 4 is manufactured as in steps S9 to S12 of 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 counter substrate base material 8 is a substrate base material for forming a wiring pattern for the counter substrate for a plurality of liquid crystal panels. In FIG. 4, only the region near the wiring pattern for one liquid crystal panel is shown. It is shown.
[0030]
In FIG. 4, a color filter 23 is formed on the surface of the prepared counter-side substrate base material 8 (step S9 in FIG. 6), and a plurality of linear counter electrodes 24 are formed in parallel with each other using ITO, and at the same time. IC output terminal 26 and IC input terminal 27 are formed (step S10 in FIG. 6). Next, an alignment film is formed on the surface of the opposite substrate base material 8 (step S11 in FIG. 6), and an alignment process such as a rubbing process is performed on the alignment film (step S12 in FIG. 6). Thereby, the opposing side substrate base material 8 is completed.
[0031]
Thereafter, the element-side substrate base material 1 (FIG. 1) and the counter-side substrate base material 8 (FIG. 4) manufactured as described above are bonded to each other with the sealant 9 (FIG. 1) interposed therebetween. A base material is formed (step S13 in FIG. 6), and then the panel base material is heated to cure the sealing material 9 (step S14 in FIG. 6). Next, 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 the liquid crystal inlets of the plurality of liquid crystal panel parts included in the panel base material are not exposed to the outside, a panel base material cutting process, a so-called break process, is performed as necessary. The liquid crystal inlet of the liquid crystal panel is exposed to the outside.
[0032]
Thereafter, a break process is performed in step S16 of FIG. Specifically, in FIG. 1, cutting linear grooves, so-called scribe lines L 1, L 2, L 3, and L 4 are formed with respect to the element side substrate base material 1, and further, in FIG. Lines L5, L6, L7, and L8 are formed. Then, the substrate on the opposite side with respect to each scribe line is hit or pressed to cut the substrate base materials 1 and 8 with the scribe line as a base point, whereby a plurality of liquid crystal panels as shown in FIG. 5 are obtained. Produced. At this time, the liquid crystal driving IC 12 is not yet mounted.
[0033]
When the above steps are performed, static electricity is generated in the element-side substrate base material 1 (FIG. 1), which may flow through the signal lines 2. In particular, such static electricity is likely to occur in the break process (step 16 in FIG. 6). However, in this embodiment, since the conductive pattern 19 is formed in step S4 and the plurality of IC output terminals 6 and hence the signal electrode 2 and the plurality of IC input terminals 7 are electrically connected to each other, a potential difference is generated between these elements. There is no. As a result, it is possible to reliably prevent static electricity from flowing through each signal line 2 and destroying the TFD element 3.
[0034]
After that, in step S17 of FIG. 6, a conductive pattern removing process is performed to remove the conductive pattern 19 shown in FIG. Specifically, an etching solution capable of etching the material constituting the conductive pattern 19, in the case of this embodiment, Cr is prepared, and the region of the liquid crystal panel where the conductive pattern 19 is formed is immersed in the etching solution. To do. Thereby, the conductive pattern 19 is removed from the element side substrate 1a. As a result, each IC output terminal 6, and hence each signal line 2 and each IC input terminal 7, are electrically independent, and as a result, each signal line 2 can function as a data line or a scanning line.
[0035]
Thereafter, in FIG. 5, a liquid crystal driving IC 12 is adhered to the IC mounting region A of the element side substrate 1a and the opposite side substrate 8a using the ACF 11, and further, polarizing plates 13 and 13 are provided on the outer surfaces of the substrates 1a and 8a. By sticking, the liquid crystal device is completed. At this time, the input bump of the liquid crystal driving IC 12, that is, the input terminal, is conductively connected to the land at the tip of the IC input terminal 7, and the output bump of the liquid crystal driving IC 12, that is, the output terminal, is conductive to the land at the tip of the IC output terminal 6. Connecting. Note that an illumination device such as a backlight is additionally provided on the outer side of either the element-side substrate 1a or the counter-side substrate 8a as necessary.
[0036]
In the above description, the conductive pattern 19 is removed by etching before the liquid crystal driving IC 12 is bonded, that is, mounted on the element side substrate 1a using the ACF 11. However, instead of this processing method, the conductive pattern 19 may be removed by an etching process that does not adversely affect the liquid crystal driving IC 12 after the liquid crystal driving IC 12 is mounted.
[0037]
According to this method, since the conductive pattern 19 exists even during the mounting operation of the liquid crystal driving IC 12, it is possible to prevent the element from being destroyed by static electricity during the mounting operation. When performing etching for removing the conductive pattern 19 after mounting the liquid crystal driving IC 12 in this manner, it is desirable to cover the liquid crystal driving IC 12 with a resin mold and shield it from the etching operation.
[0038]
The present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to the embodiments, and various modifications can be made 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, the present invention can be applied to a liquid crystal device using a TFT element instead of the TFD element.
[0039]
【The invention's effect】
According to the method for manufacturing a liquid crystal device according to the present invention, since a plurality of signal lines connected to an active element such as a TFD element are made conductive by a conductive pattern and a potential difference is generated between them, the process after forming the conductive pattern is eliminated. 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 processes.
[Brief description of the drawings]
FIG. 1 is a plan view showing a substrate structure produced in the course of a manufacturing method of a liquid crystal device according to the present invention, particularly a region for one liquid crystal panel of an element side substrate base material.
FIG. 2 is an enlarged view showing an X portion in FIG. 1;
FIG. 3 is a perspective view showing an example of an active element and a peripheral structure thereof.
FIG. 4 is a plan view showing a substrate structure manufactured in the course of the method of manufacturing a liquid crystal device according to the present invention, particularly a region for one liquid crystal panel of a counter substrate base material.
FIG. 5 is a perspective view showing 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 that is manufactured in the course of manufacturing a liquid crystal device using a conventional method for manufacturing a liquid crystal device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Element side board | substrate base material 1a Element side board | substrate 1b External exposure area | region 2 Signal line 3 TFD element (active element)
4 Pixel electrode 6 IC output terminal 7 IC input terminal 8 Opposite side substrate base material 8a Opposite side substrate 8b External exposed region 9 Seal material 11 ACF
12 Liquid crystal drive IC
13 Polarizing plate 14 First electrode 16a, 16b of TFD element Common wiring 17 Insulating film 18 of TFD element Second electrode 19 of TFD element 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-L8 Scribe line

Claims (6)

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;
Conductive pattern formation in which a conductive pattern for electrically connecting the plurality of signal lines to each other is formed by conductive connection with a portion of the plurality of signal lines extending to an externally exposed region of the element-side substrate base material except for a tip portion. Process,
Bonding the element side substrate base material and the opposite side substrate base material;
A step of cutting the bonded substrate substrate base material and the opposing substrate base material into individual liquid crystal device parts, and simultaneously exposing the externally exposed region to the outside;
A conductive pattern removing step of removing the conductive pattern formed in the externally exposed region by performing an etching process on the externally exposed region that has been exposed to the outside by the breaking step. A method for manufacturing a liquid crystal device.   2. The method of manufacturing a liquid crystal device according to claim 1, wherein the conductive pattern is simultaneously patterned with the same material when patterning a metal constituting the active element. 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;
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
Bonding the element side substrate base material and the opposite side substrate base material;
A step of cutting the bonded substrate substrate base material and the opposing substrate base material into individual liquid crystal device parts, and simultaneously exposing the externally exposed region to the outside;
A conductive pattern removing step of removing the conductive pattern formed in the externally exposed region by performing an etching process on the externally exposed region that has been exposed to the outside by the breaking step;
The liquid crystal device is a liquid crystal device having a structure in which a liquid crystal driving IC is directly mounted on an IC mounting region of an element side substrate for one liquid crystal device formed by cutting the element side substrate base material.
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 IC input terminals connected to the input terminal of the liquid crystal driving IC are formed,
In the conductive pattern forming step, an annular conductive pattern is formed that electrically connects all of the plurality of IC output terminals and the plurality of IC input terminals to each other.   4. The method for manufacturing a liquid crystal device according to claim 3, wherein the annular conductive pattern is formed outside the IC mounting region.   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. .   6. The method of 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 the conductive pattern removing step is performed.

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