JPH1062735A - Manufacturing method of liquid crystal display device and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect a liquid crystal structure from electrostatic destruction, especially to prevent wiring and element from electrostatic destruction, generated by a potential difference between two substrates. SOLUTION: When at least either of a connected pattern 13 or a substrate connection pattern 24 is coated with conductive adhesive 31 and an element substrate and an opposing substrate are normally stuck together, the connection pattern 13 and the substrate connection pattern 24 become conductive with the conductive adhesive 31. Thus, it is possible to make a wiring layer 12 and opposing electrodes 22 have a same potential and prevent elements, wiring lines and the opposing electrodes from destruction and damage caused by electric discharge between both electrodes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal display device, and more particularly to a technique for preventing electrostatic discharge of a device structure during a manufacturing process.

[0002]

2. Description of the Related Art A general process for manufacturing a liquid crystal display device is generally as follows. First, a wiring pattern, a pixel electrode, an alignment film, etc. are formed on each of the two substrates,
A sealing material is applied to one of the substrates in such a shape as to define a liquid crystal enclosing region, and the two substrates are bonded via the sealing material. After the sealing material is cured and the two substrates are fixed (finally fixed), liquid crystal is injected into a liquid crystal sealing region from a liquid crystal injection port formed in a part of the sealing material.

In particular, when a plurality of liquid crystal injection regions are formed on the substrate, after the liquid crystal is injected, the liquid crystal injection regions of the two substrates are cut off to form a liquid crystal panel having the liquid crystal injection regions one by one. Form.

In the above-described manufacturing process, wiring and electrodes are prevented from being damaged by electrostatic discharge generated during the process, and a material having high insulating properties is used to prevent the substrate from being charged. Processing,
If charging cannot be avoided, a stage conductively connected to ground potential may be used to release the charge. In particular, a TFT (thin film transistor) element or MIM
In some cases, an active element such as a (metal-insulator-metal) element is formed for each pixel. In such a case, the active element is often destroyed by static electricity generated during the process. Caution must be taken.

[0005]

However, in recent years, liquid crystal display devices have been rapidly improved in display quality, higher definition, and larger screens due to market needs and technological innovation. The demand for advanced processing is increasing, and the difficulty of handling processed products such as parts and semi-finished products during production is rapidly increasing.

In particular, due to the complexity of wiring patterns formed on a substrate and the miniaturization of active elements,
Damage to wiring and destruction of elements due to static electricity generated during the manufacturing process have become serious problems. Therefore, it is difficult to completely prevent electrostatic breakdown by the above measures,
In particular, the active elements are often destroyed by discharge between the substrates after the substrates are bonded.

Accordingly, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to protect a liquid crystal structure from electrostatic destruction in a manufacturing process of a liquid crystal display device. An object of the present invention is to prevent generated electrostatic breakdown of wirings and elements.

[0008]

Means taken by the present invention to solve the above-mentioned problem is that a first pattern is formed by forming a conductive pattern formed of an electrode, a wiring pattern and the like corresponding to a pixel region. A liquid crystal display comprising: a bonding step of bonding a substrate and a second substrate; and a panel separating step of forming a liquid crystal panel by separating peripheral portions of the first substrate and the second substrate bonded to each other. In the method for manufacturing a device, before the bonding step, a conductive material is interposed between the peripheral portions of the conductive patterns of the first substrate and the second substrate, and in the bonding step, The conductive patterns of the first substrate and the second substrate are formed to be substantially conductively contacted by the conductive material, and the first substrate and the second substrate are formed in the panel separating step.
And separating the conductive material together with the peripheral portion of the substrate.

According to this means, in the substrate bonding step, the conductive pattern on the first substrate and the second conductive pattern are bonded by the conductive material.
The conductive patterns of the two substrates are substantially conductively connected to each other, so that a large potential difference due to static electricity is prevented from being generated between the conductive patterns on both substrates. Pattern damage is prevented.

The wording "substantially" in the above description of "the conductive patterns are substantially conductively connected to each other by the conductive material" means that the conductive pattern is formed between the conductive patterns on both substrates.
If a small gap portion 22a, 22b as shown in FIG. 6 is formed, a large potential difference is generated on both sides of the gap even if the gap is not completely conductively connected.
The meaning includes a situation in which the generation of a potential difference equal to or greater than a predetermined value due to the discharge is prevented.

The conductive material may include a first connection pattern connected to the conductive pattern formed on the first substrate at the peripheral portion, and a conductive pattern formed on the second substrate. It is preferable that a conductive connection be made between the second connection pattern and the second connection pattern connected at the peripheral portion.

According to this means, the first connection pattern is formed on the periphery of the first substrate, and the second connection pattern is formed on the periphery of the second substrate. By forming the conductive material to be conductively connected between the two connection patterns, the conductive patterns on both substrates can be reliably conducted.

[0013] The conductive material may be a spacer included in a sealing material defining a liquid crystal enclosing region for bonding the first substrate and the second substrate, or the first substrate and the second substrate. It is preferable to use a paste material containing conductive particles having a diameter equal to or larger than that of the spacer dispersed between the substrate and the substrate.

According to this means, handling such as coating is facilitated by using the conductive material as a paste material, and the paste material contains conductive particles having a diameter equal to or larger than the spacer. Since the conductive particles can be reliably brought into contact with the surfaces of both substrates at the time of bonding the substrates, reliable conduction can be obtained.

Further, the sealing material defining a liquid crystal enclosing region for bonding the first substrate and the second substrate is an anisotropic conductive material that conducts only in a bonding direction of the substrates. The conductive pattern of the first substrate and the conductive pattern of the second substrate are formed in a shape that does not overlap each other in the formation region of the sealing material, and the conductive material is made of the same material as the sealing material at the same time. By arranging, it is preferable to interpose between the periphery of the first substrate and the peripheral portion of the second substrate.

According to this means, even if the sealing material is an anisotropic conductive material, the conductive patterns on both substrates do not overlap each other in the formation region of the sealing material. Not done. On the other hand, since the conductive material can be formed of the same material as the sealing material at the same time, a separate process is not required, and the manufacturing cost can be reduced.

Here, the conductive material may be formed of a spacer having a diameter equal to or larger than that of a spacer included in the sealing material or a spacer dispersed between the first substrate and the second substrate. It may be a paste material containing conductive particles.

It is preferable that the conductive material also serves as a temporary fixing adhesive for temporarily fixing the first substrate and the second substrate in the bonding step.

According to this means, the two substrates can be temporarily fixed by the conductive material, so that a separate process for forming the conductive material is not required, and the manufacturing process can be made more efficient.

Further, in the liquid crystal display device of the present invention, a first substrate and a second substrate each having a conductive pattern formed of an electrode, a wiring pattern and the like formed corresponding to a pixel region are bonded to each other, In a liquid crystal display device in which a peripheral portion of the first substrate and the second substrate bonded to each other is separated to form a liquid crystal panel, a peripheral portion of the conductive pattern of the first substrate and the second substrate is formed. A conductive material is interposed between the first substrate and the second substrate so that the conductive patterns of the first substrate and the second substrate are substantially conductively contacted by the conductive material. And separating the conductive material together with the peripheral portion of the substrate.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a method for manufacturing a liquid crystal display device according to the present invention will be described with reference to the accompanying drawings. In this embodiment, a TIM having an MIM element for each pixel is used.
This is an example in which the present invention is applied to a transmission type liquid crystal display device of an N-type active matrix type. However, the present invention is not limited to such a type of liquid crystal display device, and can be widely applied to various types of liquid crystal display devices as long as the substrate is provided with a conductive pattern such as an electrode or a wiring layer. It is.

In the embodiment described below, a large-size panel is formed by performing a substrate bonding process using substrates of a size corresponding to two liquid-crystal-filled regions, and two liquid-crystal-filled portions are formed in the large-size panel. The present invention is applied to a manufacturing process in which a region is formed, a liquid crystal sealing process is performed, and two liquid crystal panels are separated from the large format panel by a panel separating process.

However, a number of liquid crystal enclosing regions may be formed on a large format panel to form a number of liquid crystal panels. For example, a single liquid crystal enclosing region may be formed on a large format panel and the periphery of the large format panel may be formed. Only a portion may be cut and removed in the panel separating step to form a single liquid crystal panel.

FIG. 1 schematically shows a planar structure of an element substrate 10 in this embodiment. On the surface of the element substrate 10, two liquid crystal encapsulation scheduled areas 11, 11 are set,
A large number of pixel regions (not shown) are formed inside the liquid crystal sealing planned region 11. The plurality of pixel regions are arranged along the wiring layer 12 extending in parallel inside the liquid crystal filling planned region 11.

In the pixel area, the MIM element connected to the wiring layer 12 and the ITO connected to the MIM element are provided.
A transparent pixel electrode made of (indium tin oxide) is formed. The MIM element is formed by, for example, anodizing the surface of a wiring layer 12 made of Ta to form an insulating film made of Ta oxide, and forming an electrode layer made of a metal such as Cr on the insulating film. .

A plurality of wiring layers 12 constituting a conductive pattern on the element substrate 10 each extend to the outside (peripheral portion) of the liquid crystal encapsulating area 11, and are conductively connected to one connection pattern 13 at the tip. Have been. The connection pattern 13 is also a power supply line for applying an anodic oxidation voltage when anodizing the surface of the wiring layer 12.

FIG. 2 schematically shows a planar structure of the counter substrate 20 in this embodiment. On the surface of the counter substrate 20, two liquid crystal sealing regions 21 and 21 corresponding to the liquid crystal sealing region 11 of the element substrate 10 are set, and a plurality of stripe-like counter electrodes made of ITO are formed therein. 22 are formed. The counter electrode 22 faces a pixel electrode (not shown) on the element substrate 10 and applies a predetermined drive voltage to a liquid crystal layer disposed therebetween.

The counter electrode 22 is provided outside the liquid crystal encapsulation area 21 (peripheral edge) with the area connection patterns 23, 23 which are connection patterns provided for each liquid crystal encapsulation area 21.
Connected to. Further, the two area connection patterns 2
3 is connected to one board connection pattern 24. These region connection patterns 23 and substrate connection patterns 24
Is also a wiring for preventing static electricity between the opposing electrodes on the opposing substrate 20.

Note that an alignment film made of polyimide resin, polyvinyl alcohol, or the like is appropriately formed on the surfaces of the element substrate 10 and the counter substrate 20, and rubbing may be performed in a predetermined direction. Also. In the case of a color liquid crystal display device, a color filter is formed on the surface of the counter substrate 20 (the upper layer or the lower layer of the counter electrode 22).

A sealing material (not shown) is applied to at least one of the element substrate 10 shown in FIG. 1 and the counter substrate 20 shown in FIG. The two substrates are bonded together by a material. FIG. 3 shows a state where the element substrate 10 and the counter substrate 20 are attached to each other. The sealing material 30 is applied so as to extend along the liquid crystal filling regions 11 and 21, and a part thereof is formed to be an opening serving as a liquid crystal injection port 30 a. Is defined.

In the present embodiment, as shown in FIG. 1, on the connection pattern 13 and on the element substrate 10
2, and at least one of a region 25 located on the substrate connection pattern 24 and at a corner of the opposing substrate 20 as shown in FIG.
The conductive adhesive 31 shown in FIG. 3 is applied. The region 14 and the region 25 are set in advance so as to face each other in a state where the element substrate 10 and the counter substrate 20 are properly bonded.

The conductive adhesive 31 is applied to the connection pattern 13
The wiring layer 12 and the opposing electrode 22 can be set to substantially the same potential by bonding the two substrates to each other so as to conduct between the substrate connection pattern 24. Therefore, it is possible to prevent element destruction due to discharge between the two substrates, damage to wiring lines and counter electrodes, and the like.

In this case, the conductive adhesive 31 is applied to the element substrate 1
It is preferable that the adhesive also serves as a temporary fixing adhesive between the substrate and the counter substrate 20. In the substrate bonding step, the two substrates are bonded together in a correct positional relationship via a sealing material (temporary fixation), and then pressurized so as to obtain an accurate gap between the substrates, thereby curing the sealing material 30. In general, it is fixed (fixed). At this time, the conductive adhesive 31
Can also be used as a temporary fixing adhesive, thereby making it possible to perform manufacturing in a process similar to a conventional manufacturing process.

It is desirable to provide a plurality of temporary fixing adhesives outside the liquid crystal sealing region of the substrate, particularly at a plurality of corners of the substrate. It is preferable that those not to be formed be applied to the corners (for example, four places) of the substrate.

As the conductive adhesive 31, it is preferable to use a temporary fixing photo-curable adhesive obtained by adding conductive particles. For example, conductive particles obtained by subjecting a resin ball to Ni plating, Au plating, Ag plating, or the like may be used as a conductive particle.
It is desirable to add about 10 to 10 wt%, preferably about 0.1 to 1 wt%. As the conductive particles, other metal particles, conductive resins, and the like can also be used.

It may not always be required to perform the bonding function like the conductive adhesive 31, and a mere conductive material may be disposed so as to be interposed between the two substrates. In this case, it is preferable in handling that the conductive material is in the form of a paste,
Various conductive pastes can be used.

The metal-coated resin particles and other conductive particles have a diameter substantially equal to the effective diameter of the glass fiber as a spacer added to the sealing material 30.
Alternatively, a member having a diameter larger than that is preferable in order to reliably obtain conduction.

FIG. 4 shows a state in which the element substrate 10 and the opposing substrate 20 are bonded together with a sealing material 30 interposed therebetween. As shown in this figure, a glass fiber 32 may be mixed into the sealing material 30 to be used as a spacer. In this case, the conductive particles 33 contained in the conductive adhesive 31 are removed by glass. The diameter of the conductive adhesive 31 should be approximately the same as the effective diameter of the fiber 32 (the diameter defining the substrate spacing when functioning as a spacer between the substrates) or slightly larger than that. It is required to ensure the status.

In this case, even if the glass fiber 32 is not mixed in the sealing material 30, a large number of spacers may be dispersed in the liquid crystal sealing region of the liquid crystal panel. In this case, Instead of the effective diameter of the glass fiber 32, the diameter of the conductive particles 33 may be determined based on the diameter of the spacer between the substrates in the same manner as described above.

In the above embodiment, the connection pattern 13 shown in FIG. 1 is a power supply line used for performing an anodic oxidation treatment for forming an insulating film necessary for forming an MIM element. Area connection pattern 23 shown in FIG.
And the substrate connection pattern 24 is a discharge prevention line formed as a countermeasure against static electricity between the wiring and the electrodes on the counter substrate 20, and these conductors are used in the process of forming another metal layer to be deposited on the substrate. It can be formed simultaneously.

In particular, the space between the counter electrode 22 formed on the surface of the counter substrate 20 and the region connection pattern 23 is shown in FIG.
Even if they are not completely conductively connected as shown in FIG.
The gaps 22a and 22b shown in FIG. 6B or FIG.
It is sufficient that the battery is discharged to release the electric charge when a dangerous potential difference is generated as in the above. Therefore, the conduction state between the two substrates may be any as long as the potential difference can be suppressed to the extent that destruction or damage due to static electricity does not occur.

Next, an embodiment slightly different from the above embodiment will be described with reference to FIG. Also in this embodiment, the basic structure of the element substrate 10 and the counter substrate 20 is exactly the same as that of the above embodiment.

In this embodiment, the sealing material 3
0, the liquid crystal sealed region is defined by using a sealing material 40 made of an anisotropic conductive material, and the element substrate 10 and the opposing substrate 2
0 is pasted. The conductive adhesive 41 is formed by applying the same material and the same material as the sealing material 40 in the same step, and is light-cured one step ahead of the sealing material for temporarily fixing the two substrates.

The conductive adhesive 41 can be formed as part or all of a dummy seal for uniforming the distance between the substrates. In order to make the spacing between the substrates uniform, it is necessary to form a plurality of dummy seals continuously outside the panel or at predetermined intervals. It is possible to simultaneously take measures to make the substrate spacing uniform.

Here, the sealing material 40 and the conductive adhesive 41
Can be configured by containing a predetermined amount of conductive particles 33 like the conductive adhesive 31 in FIG. Here, the glass fiber 32 shown in FIG. 4 may be mixed into the sealing material 40 and the conductive adhesive 41 in addition to the conductive particles. The surface of the glass fiber 32 may be provided with conductivity by plating or the like, so that conductive particles are not required.

In this embodiment, the conductive material on the surface of the element substrate 10 and the surface of the counter substrate 20 intersect only in the region where the conductive adhesive 41 is disposed, and the sealing material 40 surrounding the liquid crystal sealing region. In the formation region, the location where the wiring layer 12 intersects and the location where the counter electrode 22 intersects are configured so as not to overlap with each other. Therefore, even if the sealing material 40 is formed of an anisotropic conductive material, The conductive material structure of both substrates is not electrically connected by the sealing material 40.

The conductive material (conductive adhesives 31 and 41) configured as described above suppresses the generation of a potential difference between the element substrate 10 and the opposing substrate 20, and the element is damaged by static electricity.
Damage to the wiring and damage to the pixel electrode and the counter electrode can be prevented. Connection pattern 1 for exhibiting this effect
3. The region connection pattern 23, the substrate connection pattern 24, and the conductive adhesives 31 and 41 are finally cut and removed in the panel separating step. However, until the substrate is cut and removed, the potential difference between the two substrates can be eliminated, and the surface structures of the two substrates can be effectively protected.

When a plurality of liquid crystal panels are manufactured in the form of a large-format panel as described above, conduction between the two substrates is maintained in the state of the large-format panel, thereby preventing an accident due to static electricity. In the panel separating step for separating each liquid crystal panel, the connection pattern 13, the area connection pattern 23, the substrate connection pattern 24, and the conductive adhesives 31 and 41 may be removed at the same time.

However, the present invention is not limited to the case where a plurality of liquid crystal panels are manufactured in the form of a large-sized panel as described above, and even if the plurality of liquid crystal panels are manufactured for each single liquid crystal panel, the panel is finally manufactured. The above method can be similarly applied as long as a panel separating step of cutting the peripheral portion is provided.

There are various methods for manufacturing a plurality of liquid crystal panels from a large format panel in addition to the above. For example, after laminating a large-sized panel in which a plurality of liquid crystal enclosing areas are lined up vertically and horizontally, a primary break process (panel separating process) is performed to divide into a rectangular medium-sized panel, and liquid crystal is injected. Thereafter, there is a method in which the liquid crystal panel is formed by further dividing the medium-size panel into pieces in a secondary break step. Even in the manufacturing method having a plurality of panel separation steps as described above, by devising the connection pattern, the panel structure can be protected from static electricity until immediately before the final panel separation step.

However, in the case described above, even if a plurality of panel separation steps are present, they are included in the scope of the present invention as long as they can be protected from static electricity before any of the steps. Things.

[0052]

As described above, according to the present invention, the following effects can be obtained.

According to the first aspect, in the substrate bonding step, the conductive pattern of the first substrate is connected to the second pattern by the conductive material.
The conductive patterns of the two substrates are substantially conductively connected to each other, so that a large potential difference due to static electricity is prevented from being generated between the conductive patterns on both substrates. Pattern damage is prevented.

According to the second aspect, the first connection pattern is formed on the peripheral portion of the first substrate, and the second connection pattern is formed on the peripheral portion of the second substrate. By forming the conductive material to be conductively connected between the second connection patterns, the conductive patterns on both substrates can be reliably conducted.

According to the third or fifth aspect, by using a conductive material as a paste material, handling such as application is facilitated, and the conductive material having a diameter equal to or larger than that of the spacer is added to the paste material. Therefore, the conductive particles can be reliably brought into contact with the surfaces of both substrates at the time of bonding the substrates, so that reliable conduction can be obtained.

According to the fourth aspect, even if the sealing material is an anisotropic conductive material, the conductive patterns on both substrates do not overlap each other in the sealing material forming region. Not connected. On the other hand, since the conductive material can be formed of the same material as the sealing material at the same time, a separate process is not required, and the manufacturing cost can be reduced.

According to the sixth aspect, the two substrates can be temporarily fixed by the conductive material, so that another step of forming the conductive material is not required, and the manufacturing process can be made more efficient.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a schematic plan structure of an element substrate for describing an embodiment of a method for manufacturing a liquid crystal display device according to the present invention.

FIG. 2 is a schematic plan view showing a schematic plan structure of a counter substrate in the embodiment.

FIG. 3 is a schematic plan perspective view showing a state in which the element substrate shown in FIG. 1 and the counter substrate shown in FIG. 2 are overlaid;

FIG. 4 is a schematic sectional view showing an arrangement section of a sealing material and a conductive adhesive between an element substrate and a counter substrate in the same embodiment.

FIG. 5 is a schematic plan perspective view showing a state in which an element substrate and a counter substrate in another embodiment are overlaid.

FIG. 6 is enlarged plan views (a), (b) and (c) showing examples of various conductive patterns between a counter electrode formed on a counter substrate and a conductive connection line.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Element board 11 and 21 Area to be filled with liquid crystal 12 Wiring layer 13 Connection pattern 14 and 25 Area 20 Counter substrate 22 Counter electrode 23 Area connection pattern 24 Board connection pattern 30 Seal material 31 and 41 Conductive adhesive 33 Conductive particles

Claims (7)

[Claims] A first conductive pattern comprising an electrode, a wiring pattern and the like formed corresponding to the pixel region;
Comprising: a bonding step of bonding a first substrate and a second substrate to each other; and a panel separating step of forming a liquid crystal panel by separating peripheral portions of the first and second substrates bonded to each other. In the method for manufacturing a display device, before the bonding step, a conductive material is interposed between the peripheral portions of the conductive patterns of the first substrate and the second substrate; The conductive patterns of the first substrate and the second substrate are formed so as to be substantially conductively contacted by the conductive material. In the panel separating step, the first substrate and the second substrate are formed. A method for manufacturing a liquid crystal display device, comprising separating the conductive material together with the peripheral portion of the liquid crystal display device. 2. The method according to claim 1, wherein the conductive material is formed on a first connection pattern connected to the conductive pattern formed on the first substrate at the peripheral portion, and on the second substrate. Forming a conductive connection between the conductive pattern and a second connection pattern connected at the peripheral portion. 3. A sealing material according to claim 1, wherein said conductive material defines a liquid crystal enclosing region for bonding said first substrate and said second substrate. A paste material containing conductive particles having a diameter equal to or larger than that of the spacer included in the first substrate or the spacer dispersed between the first substrate and the second substrate. A method for manufacturing a display device. 4. The anisotropic structure according to claim 1, wherein a sealing material defining a liquid crystal enclosing region for bonding the first substrate and the second substrate is conducted only in a bonding direction of the substrates. A conductive material, wherein the conductive pattern of the first substrate and the conductive pattern of the second substrate are formed so as not to overlap with each other in a region where the sealant is formed; A method for manufacturing a liquid crystal display device, characterized by interposing between the peripheral portions of the first substrate and the second substrate by arranging the same material at the same time. 5. The method according to claim 4, wherein the conductive material is equal to or larger than a spacer included in the sealing material or a spacer dispersed between the first substrate and the second substrate. A paste material containing conductive particles having a large diameter. 6. The method according to claim 1, wherein the conductive material also serves as a temporary fixing adhesive for temporarily fixing the first substrate and the second substrate in the bonding step. Manufacturing method of a liquid crystal display device. 7. A first pattern formed by forming a conductive pattern including an electrode, a wiring pattern, and the like formed corresponding to a pixel region.
A liquid crystal display device that forms a liquid crystal panel by bonding the first substrate and the second substrate, which are bonded to each other, and separating peripheral portions of the first substrate and the second substrate that are bonded to each other. A conductive material is interposed between the peripheral portions of the conductive pattern of the second substrate so that the conductive patterns of the first substrate and the second substrate are substantially conductively contacted by the conductive material. Form, then
A liquid crystal display device characterized in that the conductive material is cut off along with the peripheral portions of the first substrate and the second substrate.