JP2010204405A - Method for manufacturing in plane switching liquid crystal display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an in-plane switching liquid crystal display panel that suppresses breakage of a substrate in a manufacturing process. <P>SOLUTION: The method includes: a first step (S1 and S2) for preparing a first mother substrate and a second mother substrate on which a plurality of liquid crystal display panel areas are formed; a second step (S3) for annularly applying a sealing material to at least one surface of the first mother substrate and the second mother substrate along their outer circumference, and applying the sealing material to the circumference of each of the plurality of areas for forming a liquid crystal display panel; a third step (S4) for bonding the first mother substrate and the second mother substrate in a vacuum; a fourth step (S5) for forming a conductive film on the rear surface of one of the bonded mother substrates in a vacuum; a fifth step (S6) for dividing the bonded mother substrates into strips in a vacuum; a the sixth step (S8) for dividing the strip-like mother substrates into liquid crystal display panels. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a method of manufacturing a horizontal electric field type liquid crystal display panel. Specifically, the present invention relates to I
When manufacturing a liquid crystal display panel driven by a lateral electric field method such as PS (In-Plane Switching) mode or FFS (Fringe Field Switching) mode, a pair of opposing mother substrates are bonded together in a vacuum, and then the vacuum conditions The present invention relates to a method of manufacturing a horizontal electric field type liquid crystal display panel in which a process such as sputtering for forming a conductive film as an electrostatic shield is performed below.

Liquid crystal display panels are characterized by their light weight, thinness, and low power consumption compared to CRTs (cathode ray tubes), and are therefore used in many electronic devices for display purposes. The liquid crystal display panel displays an image by changing the direction of liquid crystal molecules aligned in a predetermined direction by an electric field and changing the amount of light transmitted through the liquid crystal layer. As a method of applying an electric field to a liquid crystal layer of a liquid crystal display panel, there are a vertical electric field type and a horizontal electric field type. A vertical electric field type liquid crystal display panel applies a substantially vertical electric field to liquid crystal molecules by a pair of electrodes arranged with a liquid crystal layer interposed therebetween. This vertical electric field type liquid crystal display panel includes TN (Twisted Nematic) mode, VA (Vertica
l Alignment) mode, MVA (Multi-domain Vertical Alignment) mode, etc. are known.

A horizontal electric field type liquid crystal display panel is provided with a pair of electrodes insulated from each other on the inner surface side of one of a pair of substrates arranged between a liquid crystal layer, for example, an array substrate and a color filter substrate. A substantially horizontal electric field is applied to the liquid crystal molecules. As the horizontal electric field type liquid crystal display panel, there are known an IPS mode in which a pair of electrodes do not overlap in a plan view and an FFS mode in which they overlap. The liquid crystal display panel of the horizontal electric field type has an effect that a wide viewing angle can be obtained.

However, the horizontal electric field type liquid crystal display panel has a problem not seen in the vertical electric field type liquid crystal display panel. That is, the horizontal electric field type liquid crystal display panel includes a pair of electrodes for driving the liquid crystal only on one of the pair of substrates, and the other substrate does not include an electrode. For this reason, when an electric field caused by static electricity or the like is applied from the other substrate side, the electric field acts directly on the liquid crystal layer, resulting in a display abnormality. For it,
In a vertical electric field type liquid crystal display panel, a pixel electrode is formed on one substrate and a counter electrode or a common electrode is formed on the other substrate, so even if an electric field caused by static electricity is applied from the outside. Since this electric field is blocked by the pixel electrode, the counter electrode, or the common electrode, it does not act on the liquid crystal layer, so that display anomalies unlike a horizontal electric field type liquid crystal display panel are unlikely to occur.

Therefore, in order to solve such problems, conventionally, in a horizontal electric field type liquid crystal display panel, a conductive layer or a conductive film having a shielding function against static electricity or the like is formed on a color filter substrate. For example, in Patent Document 1 below, an ITO (Indium Thin Oxide) film as a transparent conductive film is formed on almost the entire outer surface side of a transparent substrate of a color filter substrate, and a polarizing plate is attached to the upper surface of the ITO film. Such a horizontal electric field type liquid crystal display device is disclosed. According to the lateral electric field type liquid crystal display device disclosed in the following Patent Document 1, even when a high potential such as static electricity is applied to the surface of the liquid crystal display panel from the outside, the occurrence of abnormal display is prevented. It is said that durability, environmental resistance, reliability, and the like can be improved. The ITO film as such a shield layer is formed by, for example, a sputtering method in a vacuum or a reduced pressure atmosphere, and is usually formed after applying a sealing material to the peripheral portions of a pair of transparent substrates and bonding them together. It is supposed to.

Further, in Patent Document 2 below, a transparent conductive film is attached to the display screen side of the liquid crystal display panel, and a grounding means for electrically energizing the transparent conductive film to the grant is disposed, and the liquid crystal display panel is electromagnetically coupled. A liquid crystal display device having a shield is disclosed. According to the liquid crystal display device disclosed in Patent Document 2 below, this electromagnetic wave shield prevents electromagnetic waves entering and exiting through the display screen, eliminates various adverse effects such as malfunction of surrounding electronic devices, and prevents electromagnetic interference. It is said that a strong liquid crystal display device can be obtained.

JP 09-105918 JP2002-341372

In the liquid crystal display devices disclosed in Patent Documents 1 and 2, a conductive layer or a conductive film is formed on the display surface side to provide a shielding function against static electricity or the like. Each of these conductive layers or conductive films is formed by sputtering or vapor deposition of an ITO film in vacuum. However, in a manufacturing process of a horizontal electric field type liquid crystal display panel, a pair of mother substrates are bonded together by a rigid press or the like at atmospheric pressure, and then a conductive film such as ITO is formed by a film forming process such as sputtering in a vacuum. When forming, the mother substrate sometimes cracked.

As a result of various studies on the cause of such a crack of the mother substrate, the inventors have found that the cause is as follows. That is, because the bonding process is performed under atmospheric pressure, the inside of the mother substrate is at atmospheric pressure, whereas the process of forming a conductive film such as ITO is performed in a vacuum. The outside of the mother board becomes a vacuum atmosphere. For this reason, during the process of forming a conductive film such as ITO, the mother substrate is deformed by a pressure difference between the inside and the outside of the mother substrate, which causes the mother substrate to crack.

As a result of various studies to solve the problems of the prior art as described above, the inventors have formed an outer peripheral sealing material, which is different from the sealing material for the liquid crystal display panel, on the outer periphery of the mother substrate. The inventors have found that the problem can be solved by bonding a pair of mother substrates in a vacuum, and then performing a process for forming a conductive film such as ITO in the vacuum as it is, thus completing the present invention. That is, the object of the present invention is to apply ITO after bonding both mother substrates.
It is an object of the present invention to provide a method for manufacturing a horizontal electric field type liquid crystal display panel in which the mother substrate is not cracked even when the conductive film forming step is performed under vacuum conditions.

In order to achieve the above object, a method of manufacturing a horizontal electric field type liquid crystal display panel of the present invention includes:
A first step of preparing a first mother substrate and a second mother substrate on which a plurality of liquid crystal display panel regions are formed;
A second sealant is applied to at least one surface of the first mother substrate and the second mother substrate in an annular shape along an outer periphery, and a sealant is applied around each of the plurality of liquid crystal display panel formation regions. And the process of
A third step of bonding the first mother substrate and the second mother substrate in a vacuum;
A fourth step of forming a conductive film in a vacuum on the back surface of one mother substrate of both the bonded mother substrates;
Dividing the mother substrate into liquid crystal display panels;
It is characterized by providing.

In the method of manufacturing a horizontal electric field type liquid crystal display panel of the present invention, there is a step of bonding both mother substrates in a vacuum and then forming a conductive film as an electrostatic shield by sputtering or the like.
However, since sputtering or the like for forming a conductive film is performed in a vacuum, when both mother substrates are pasted together by a rigid press under atmospheric pressure as in the past, a subsequent process such as sputtering performed under vacuum conditions is performed. There is a risk of substrate cracking due to changes in pressure. That is, when both mother boards are bonded together under atmospheric pressure, the inside of both mother boards is at atmospheric pressure, whereas the outside of both mother boards is in a reduced pressure state, so both mother boards swell outward. However, since there is no fixing member on the outside of both mother boards, the swelling of both mother boards becomes large, so that there is a possibility that substrate cracking occurs.

Therefore, in the method of manufacturing a horizontal electric field type liquid crystal display panel according to the present invention, an annular outer peripheral sealing material is formed on the outer periphery of at least one mother substrate, and both the mother substrates are bonded together in a vacuum. In this state, the insides of both mother boards are in a reduced pressure state. For this reason, even if the pressure around the substrate increases (transfers to atmospheric pressure) in the subsequent manufacturing process, both mother substrates are deformed so as to be recessed inward, but the amount of deformation is the thickness of the gap between both mother substrates. It is not limited to be limited by the thickness, and the inside of both mother boards is kept in a reduced pressure state. Therefore,
According to the method of manufacturing a horizontal electric field type liquid crystal display panel of the present invention, the pressure difference between the inside and outside of both mother substrates becomes small even when the film formation of the conductive film as the electrostatic shield is performed again under vacuum conditions. Substrate cracks are less likely to occur.

According to the method for manufacturing a horizontal electric field type liquid crystal display panel of the present invention, since both mother substrates are bonded together in a vacuum, volatile impurities existing inside the substrate or on the surface of the substrate can be removed, and the liquid crystal display panel There is also an effect that the quality of the can be improved.

In the method of manufacturing a horizontal electric field type liquid crystal display panel according to the present invention, the step of dividing the mother substrate into each liquid crystal display panel is a fifth step of dividing the bonded mother substrate into a strip shape in a vacuum. When,
A sixth step of dividing the strip-shaped mother substrate into liquid crystal display panels;
Preferably it consists of.

According to the horizontal electric field type liquid crystal display panel manufacturing method of the present invention, since the process of dividing the mother substrate into strips is also performed in a vacuum, a sudden change in atmospheric pressure occurs even when the outer peripheral sealing material is cut. Therefore, substrate cracking in this manufacturing process can be suppressed.

In the method of manufacturing a horizontal electric field type liquid crystal display panel according to the present invention, the step of applying a sealing material around each of the plurality of liquid crystal display panel forming regions in the second step includes the liquid crystal display panel region. It is a step of forming so as to have a liquid crystal inlet every time,
Preferably, a liquid crystal injection step and a liquid crystal injection port sealing step are provided between the fifth step and the sixth step.

According to the method for manufacturing a liquid crystal display panel of the present invention, the effects of the above-described invention can also be exhibited in a method for manufacturing a horizontal electric field type liquid crystal display panel using a vacuum injection method in a liquid crystal injection process.

In the method of manufacturing a horizontal electric field type liquid crystal display panel according to the present invention, the step of applying a sealing material around each of the plurality of liquid crystal display panel forming regions in the second step includes the liquid crystal display panel region. It is a process of applying a sealing material in a ring shape every time,
It is preferable to include a step of dropping and injecting liquid crystal between the second step and the third step.

According to the method for manufacturing a liquid crystal display panel of the present invention, the effects of the above-described invention can also be exhibited in a method for manufacturing a liquid crystal display panel using a liquid crystal dropping method in a liquid crystal injection process.

In the method of manufacturing a horizontal electric field type liquid crystal display panel according to the present invention, the third step is preferably performed by rigid pressing in a vacuum.

According to the method of manufacturing a horizontal electric field type liquid crystal display panel of the present invention, since the substrates are bonded by a rigid press in a vacuum, a stronger bonding can be achieved as compared with a conventional method of bonding only at atmospheric pressure. It becomes like this.

In the method of manufacturing a horizontal electric field type liquid crystal display panel according to the present invention, the vacuum pressure reduction condition for bonding the two mother substrates in the third step is a vacuum pressure reduction for forming the conductive film in the fourth step. The conditions are preferably the same.

According to the manufacturing method of the horizontal electric field type liquid crystal display panel of the present invention, the decompression condition when the two mother substrates are bonded together and the decompression condition when the conductive film is formed on the back surface of one mother substrate are the same. Even if the pressure is reduced again during the formation of the conductive film, there is almost no change in the pressure inside the outer peripheral sealing material, and therefore a method of manufacturing a horizontal electric field type liquid crystal display panel in which substrate cracking is further suppressed can be provided.

The horizontal electric field type liquid crystal display panel of the present invention is a horizontal electric field type liquid crystal display panel manufactured by the manufacturing method according to any one of claims 1 to 6.

According to the liquid crystal display panel of the present invention, it is possible to provide a liquid crystal display panel having high reliability with little risk of substrate cracking.

1A is a completed plan view of the liquid crystal display panel of Embodiment 1, and FIG. 1B is a cross-sectional view taken along line IB-IB in FIG. 1A. 5 is a flowchart showing manufacturing steps of the FFS mode liquid crystal display panel of Embodiment 1. It is a perspective view when a sealing material is apply | coated to one mother board | substrate. 4A is a perspective view when both mother substrates are bonded together, FIG. 4B is a sectional view taken along line IVB-IVB in FIG. 4A, and FIG. 4C is a sectional view after bonding from FIG. 4B. . It is a simplified diagram of the process of forming a conductive film on the back surface of the color filter substrate. 6A is a diagram showing a first dividing line, FIG. 6B is a diagram showing an example of a dividing method in a vacuum, and FIG. 6C is a plan view of a mother substrate divided into strips. FIG. 7A is a diagram illustrating a process of injecting liquid crystal into the mother substrate after being divided into strips, FIG. 7B is a diagram illustrating a process of injecting liquid crystal, and FIG. 7C is a diagram of injecting liquid crystal. 7D is a view in which liquid crystal is completely injected, and FIG. 7E is a view in which liquid crystal is injected and the liquid crystal injection port is sealed. 8A is a completed plan view of the liquid crystal display panel of Embodiment 2, and FIG. 8B is a cross-sectional view taken along line VIIIB-VIIIB of FIG. 8A. 6 is a flowchart showing a manufacturing process of an FFS mode liquid crystal display panel of Embodiment 2. FIG. 10A is a perspective view when a sealing material is applied to one mother substrate, and FIG. 10B is a perspective view when liquid crystal is dropped onto the other mother substrate. 11A is a perspective view when both mother substrates are bonded together, FIG. 11B is a sectional view taken along line XIB-XIB in FIG. 11A, and FIG. 11C is a sectional view after bonding from FIG. 11B. . FIG. 12A is a diagram showing a first dividing line, FIG. 12B is a diagram showing an example of a dividing method in a vacuum, and FIG. 12C is a plan view of a mother substrate divided into strips.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to examples and drawings. However, the embodiment shown below is used to embody the technical idea of the present invention.
The method of manufacturing the FS mode liquid crystal display panel will be described as an example, and the present invention is not intended to be specified as the method of manufacturing the FFS mode liquid crystal display panel described in this embodiment. The invention is equally applicable to other embodiments within the scope of the claims. In each drawing used for the description in this specification, each layer and each member are displayed in different scales so that each layer and each member can be recognized on the drawing. However, it is not necessarily displayed in proportion to the actual dimensions. The “surface” of the array substrate and the color filter substrate described below indicates the surface on which various wirings are formed or the surface facing the liquid crystal, and the “back surface” indicates the display surface side (
The surface of the color filter substrate) or the backlight side (in the case of an array substrate) is shown.

[Embodiment 1]
First, with reference to FIG. 1, the structure of the liquid crystal display panel manufactured by the manufacturing method of the FFS mode liquid crystal display panel of this Embodiment 1 is demonstrated. As shown in FIGS. 1A and 1B, the liquid crystal display panel 10A according to the first embodiment includes an array substrate 11 in which various wirings are formed on a transparent substrate 12 made of glass or the like, and a color filter on a transparent substrate 15 made of glass or the like. The color filter substrate 14 formed with the like and the like is disposed to face each other. A conductive film 17 serving as an electrostatic shield is formed on the back surface of the color filter substrate 14.

The array substrate 11 is slightly larger in size than the color filter substrate 14 so that an overhanging portion 12a having a predetermined space is formed when the array substrate 11 is arranged opposite to the color filter substrate 14. A driver IC 21 or the like for driving the liquid crystal is disposed on the overhanging portion 12a.

The array substrate 11 has a sealing material 1 around it except for a portion where the liquid crystal injection port 19 is formed.
8a is applied. A region surrounded by the sealing material 18 a is a display region 22. A photo spacer (not shown) is formed between the array substrate 11 and the color filter substrate 14 so as to have a certain gap (cell gap), and is bonded to each other with a sealing material 18. The liquid crystal 23 is injected into the display region 22 of the array substrate 11 from the liquid crystal injection port 19 formed in the sealing material 18a on the substrate side, and then the sealing material 20 is applied to the liquid crystal injection port 19 and sealed. It has become.

  Next, the manufacturing process of the liquid crystal display panel of Embodiment 1 will be described with reference to FIGS.

The first mother substrate 11M on the array substrate side is formed as a variety of wiring such as signal lines and scanning lines and switching elements by repeatedly forming and patterning a metal film, an insulating film, a resin film, etc. on a transparent substrate 12 such as glass. Thin film transistors (TFTs), ITO and IZ
A lower electrode made of a transparent conductive material such as O (Indium Zinc Oxide), an interelectrode insulating film, an upper electrode made of a transparent conductive material such as ITO or IZO, an alignment film, etc. Formed to include. In FIG. 1B, these are collectively referred to as the structure 13. Then, the alignment film is rubbed to complete the first mother substrate 11M (step S1).

Further, the second mother substrate 14M on the color filter side repeats the formation and patterning of a metal film, a resin film, an insulating film, etc. on the transparent substrate 15 such as glass, and the light shielding layer, the color filter layer, the overcoat layer, the orientation. It is formed so as to be provided with a film or the like. In FIG. 1B, these are collectively referred to as the structure 16. Then, the alignment film is subjected to a rubbing process to form a second mother substrate 1
4M is completed (step S2).

Next, as shown in FIG. 3, a sealing material for bonding the mother substrates 11M and 14M is applied. This sealing material is applied using, for example, a dedicated seal dispenser 24.
At this time, the seal material is a seal material (hereinafter referred to as “peripheral seal material”) 18 applied to the outer periphery of the mother substrate surface, and a liquid crystal injection port 19 in a part so as to surround each liquid crystal display panel formation region 25. Both of the sealing material (hereinafter referred to as “panel sealing material”) 18a to be applied are opened (step S3). Although these sealing materials 18 and 18a can be formed on at least one of the first mother substrate 11M and the second mother substrate 14M, the first embodiment shows an example in which the sealing materials 18 and 18a are formed on the first mother substrate 11M side. As the sealing material, a thermosetting resin, an ultraviolet curable resin, or the like can be used.

Each liquid crystal display panel formation region 25 needs to be provided with a photo spacer (not shown) for keeping the cell gap between the array substrate and the color filter substrate constant. What is necessary is just to form in any one surface of a 2nd mother board | substrate.

Next, both mother substrates 11M and 14M are bonded together in a vacuum. As shown in FIG. 4A, the first mother substrate 11M and the second mother substrate 14M coated with the outer peripheral sealing material 18 and the panel sealing material 18a are arranged to face each other, and alignment marks (not shown) formed on both the mother substrates 11M and 14M. Positioning is performed by combining them. Moreover, in this Embodiment 1, as shown to FIG. 4B, bonding is performed within the apparatus 26 made into the vacuum state using the well-known vacuum generator.
Then, as shown in FIG. 4C, this bonding is performed by applying a predetermined pressure while applying heat or the like according to the sealing materials 18 and 18a to be used. A method of applying force using atmospheric pressure by changing to atmospheric pressure may be employed (step S4).

Both mother substrates 11M and 11M are bonded together in a vacuum to form both mother substrates 11M.
, The inside of the outer peripheral sealing material 18 formed in 14M is bonded together in a reduced pressure state. Therefore, this bonded mother substrate (hereinafter simply referred to as the mother substrate) 10AM
Even if exposed to atmospheric pressure, the inside of the outer peripheral sealing material 18 is kept in a reduced pressure state.
In addition, since the mother substrate 10AM is bonded under reduced pressure, volatile impurities existing inside and on the surface of the substrate can be removed, which is advantageous in terms of the quality of the completed liquid crystal display panel.

Next, as shown in FIG. 5, a conductive film 17 as an electrostatic shield for protecting the completed liquid crystal display panel 10A from static electricity or the like is formed on the back surface of the second mother substrate 14M in a vacuum atmosphere by sputtering or the like. To do. This film formation is performed here using a dedicated sputtering apparatus 27 or the like (step S5).

At this time, if both the mother substrates 11M and 14M are bonded together under atmospheric pressure as in the prior art, both the mother substrates 11M and 1M are formed when a vacuum atmosphere is formed in order to form the conductive film 17 in a later step.
Since both mother substrates are deformed so as to swell greatly outward due to the difference between the pressure inside 4M and the external pressure, there is a possibility that substrate cracking may occur. However, in the first embodiment, since both the mother substrates 11M and 14M are bonded together in a vacuum, both the mother substrates 11M and 14M.
Even after the M is bonded, the inside of the mother boards 11M and 14M is kept in a reduced pressure state. Therefore, when both mother boards 11M and 14M are taken out into the atmosphere, both mother boards 11
M and 14M are deformed so as to be recessed inward, but the amount of deformation is limited by the thickness of the gap between both mother boards 11M and 14M, and the inside of both mother boards is kept in a reduced pressure state. I'm leaning. Moreover, the mother substrate 10 is used to perform a vacuum process such as sputtering.
Even if the outside of the outer peripheral sealing material 18 of the AM is in a reduced pressure state, the difference in atmospheric pressure between the inside and outside is small, so that the possibility of substrate cracking is reduced.

In addition, since film-forming processes, such as sputtering, are well-known techniques, detailed description is abbreviate | omitted. In addition to sputtering, the film formation process includes a vacuum deposition method and a chemical vapor deposition method (CVD). Further, the decompression condition in the vacuum state in step S4 and step S5 is that if the decompression condition in the bonding process is matched with the maximum decompression condition in the film forming process, the decompression condition is applied even if the vacuum state is again in the film forming process. Since it is the same as the alignment, the burden on the substrate can be greatly reduced.

Next, a first dividing step is performed in which the mother substrate 10AM is divided into strips in a vacuum. This first
In the dividing step, the mother substrate 10AM is divided into strips along the first dividing line 28, as shown in FIG. 6A. Moreover, the 1st parting process is performed with the laser beam 30 irradiated from the laser cutter 29 within the apparatus 31 made into the vacuum state in the vacuum generator, as shown to FIG. 6B.
In step 4, the mother substrate 10AM bonded in a vacuum state is still kept in a reduced pressure inside the outer peripheral sealing material 18. Therefore, if this first parting step is performed at atmospheric pressure, when the outer peripheral sealing material 18 is cut, the internal pressure of the outer peripheral sealing material 18 rapidly increases, and there is a risk of substrate cracking. Therefore, this first cutting process is also performed in a vacuum state (step S6).

In addition, as a dividing method, a method using a combination of a scribe method and a break method, a method using a wheel cutter, and the like are known. In the first embodiment, the first dividing is performed in a vacuum state. Therefore, the method using the laser cutter 29 was adopted. In addition, as shown in FIG. 6C, a part of the outer peripheral sealing material 18 remains in the strip-like mother substrate 10AS.

Next, a liquid crystal injection process will be described with reference to FIGS. 7A to 7E. This process starts with FIG. 7A.
As shown in FIG. 5, the strip-shaped mother substrate 10AS is installed so that the liquid crystal injection port 19 faces downward, and the liquid crystal 23 is prepared in accordance with the position corresponding to the liquid crystal injection port 19. At this time, the inside of the injection device (not shown) for the liquid crystal 23 is depressurized to a vacuum state. Next, as shown in FIG. 7B, the liquid crystal 23 is brought into contact with the liquid crystal inlet 19 of the strip-shaped mother substrate 10AS. Then, as shown in FIG. 7C, the liquid crystal 23 is transferred from the liquid crystal inlet 19 to each liquid crystal display panel 1 by a so-called capillary phenomenon.
It enters the display area 22 of 0A. Thereafter, when the inside of the injection device for the liquid crystal 23 is returned to the atmospheric pressure after a while, the liquid crystal 23 further spreads to every corner of the display region 22 as shown in FIG. 7D. Thereafter, as shown in FIG. 7E, the liquid crystal injection port 19 is sealed with the sealing material 20, and the liquid crystal injection is completed (step S7).

In the second dividing step, the strip-like mother substrate 10AS is divided into a panel shape. Liquid crystal 23
After completion of the injection, the strip-shaped mother substrate 10AS is divided along the second dividing line 32 shown in FIG. 7E and divided into individual panels. Here, a part of the remaining outer peripheral sealing material 18 is cut and removed together with the end portion of the mother substrate 10AM (step S8). Then, a driver IC 21 or the like is installed on the divided liquid crystal display panel, and the first embodiment as shown in FIG. 1A.
The horizontal electric field type liquid crystal display panel 10A is completed (step S9).

[Embodiment 2]
In the first embodiment, the manufacturing method of the FFS mode liquid crystal display panel using the vacuum injection method for injecting the liquid crystal is described. In the second embodiment, the manufacturing method of the FFS mode liquid crystal display panel using the liquid crystal dropping method is described. To do. The FFS mode liquid crystal display panel manufacturing method of the second embodiment is different from the FFS mode liquid crystal display panel manufacturing method of the first embodiment in that a liquid crystal dropping method is used. Constituent elements common to the panel manufacturing method are referred to by the same reference numerals, and detailed description thereof is omitted.

With reference to FIG. 8, the structure of the liquid crystal display panel manufactured by the manufacturing method of the FFS mode liquid crystal display panel of this Embodiment 2 is demonstrated. As shown in FIGS. 8A and 8B, the liquid crystal display panel 10B according to the second embodiment is different from the liquid crystal display panel 10A manufactured by the manufacturing method according to the first embodiment in that the liquid crystal injection port 19 is not formed by the sealing material 18. The point is different. In addition,
Other configurations are the same as those of the liquid crystal display panel of the first embodiment.

  Next, the manufacturing process of the liquid crystal display panel of Embodiment 2 will be described with reference to FIGS.

First, a first mother substrate (hereinafter referred to as a first mother substrate) 11M on the array substrate side is prepared. Since this process is the same as step 1 described in the first embodiment, detailed description thereof is omitted (step S11).

Next, as shown in FIG. 10A, a sealing material for bonding both mother substrates is applied. This sealing material is applied using, for example, a dedicated seal dispenser 24. At this time, the sealing material is an outer peripheral sealing material 18 applied to the outer periphery of the surface of the first mother substrate 11M, and a sealing material (hereinafter referred to as an annular sealing material) 18b that is applied around the liquid crystal display panel forming region 25 in an annular shape.
Both are applied (step S12). The sealing materials 18 and 18b can be formed on at least one of the first mother substrate 11M and the second mother substrate 14M. FIG. 10A shows an example in which the sealing materials 18 and 18b are formed on the first mother substrate 11M side. The sealing material is thermosetting, ultraviolet curable, or a combination thereof.

Next, a second mother substrate 14M on the color filter substrate 14 side is prepared (Step S1).
3). Since this process is the same as step 3 described in the first embodiment, description thereof is omitted.

Next, as shown in FIG. 10B, the liquid crystal 23 is dropped onto the first mother substrate 11M using a dedicated liquid crystal dropping device 33. The liquid crystal 23 is in the center of each liquid crystal display panel forming region 25, that is,
It is dropped at a position corresponding to the inside of the annular sealing material 18b formed on the second mother substrate 14M (step S14).

Next, both mother substrates 11M and 14M are bonded together in a vacuum. As shown in FIG. 11A, the first mother substrate 11M coated with the outer peripheral sealing material 18 and the annular sealing material 18b and the second mother substrate 14M onto which the liquid crystal 23 has been dropped are arranged opposite to each other, and formed on both mother substrates 11M and 14M. Positioning is performed by aligning alignment marks (not shown).

In the second embodiment as well, as shown in FIG. 11B, the bonding is performed in a device 26 that is evacuated using a known vacuum generator. Then, as shown in FIG. 11C, the mother substrates 11M and 14M are bonded together, and the dropped liquid crystal 23 is filled in the display region 22.
Thereafter, the bonded mother substrate (hereinafter simply referred to as a “mother substrate”) 10BM is moved from vacuum to atmospheric pressure, and pressure is applied by atmospheric pressure to perform bonding. And sealing material 1
8, 18b is cured by heating or irradiation with ultraviolet rays (step S15).

In this manner, by bonding the both mother substrates 11M and 14M in a vacuum, the insides of the outer peripheral sealing material 18 and the annular sealing material 18b formed on the mother substrate 10BM are bonded together in a reduced pressure state. Even if the substrate 10BM is moved to atmospheric pressure, the inside of the outer peripheral sealing material 18 and the annular sealing material 18b is maintained in a reduced pressure state, and the risk of substrate cracking is reduced.

Next, a conductive film 17 as an electrostatic shield is formed on the back surface of the second mother substrate 14M (step S16). Since this step is the same as step 5 in the first embodiment, description thereof is omitted.

In the first dividing step, as shown in FIG. 12A, the dividing is performed in a strip shape along the first dividing line 28 (step S17). This process is common to step 6 of the first embodiment, but the difference is that the liquid crystal 23 is already filled in the display region 22 inside the annular sealing material 18b. There is no particular difference. In addition, division | segmentation is the said Embodiment 1.
The process is performed in a vacuum in the same manner as described in (see FIG. 12B).

In the second dividing step, as shown in FIG. 12C, the strip-shaped mother substrate 10BS is divided along the second dividing line 32 to form a panel (step S18). In addition, since a 2nd parting process is a process common to step 8 of Embodiment 1, description is abbreviate | omitted.

Then, the driver IC 21 and the like are installed to complete the horizontal electric field type liquid crystal display panel 10B of the second embodiment as shown in FIG. 8A (step S19).

According to the manufacturing method of the horizontal electric field type liquid crystal display panel according to the first and second embodiments having the above manufacturing process, several vacuum processes are performed during the manufacturing process. The inside of the outer peripheral sealing material is kept in a reduced pressure state by forming. Therefore, it is possible to suppress substrate cracking due to changes in atmospheric pressure.

Moreover, in the manufacturing method of the horizontal electric field type liquid crystal display panel according to the first and second embodiments, the outer peripheral sealing material is applied in a single layer. However, the present invention is not limited to this. May be. By doing in this way, even if formation of one perimeter seal material is inadequate, a decompression state can be maintained with other perimeter seals.

In the first and second embodiments, the method of manufacturing the FFS mode horizontal electric field type liquid crystal display panel has been described. However, the present invention is not limited to this, and the IPS mode liquid crystal display is applicable to any horizontal electric field type liquid crystal display panel. It can also be applied to panels and the like. Furthermore, the method of manufacturing a horizontal electric field type liquid crystal display panel according to the present invention is also applicable to an FFS mode horizontal electric field type liquid crystal display panel in which the formation of the interlayer film is omitted in the configuration of the first mother substrate. Can do.

As described above, according to the liquid crystal display panel manufactured by the method of manufacturing a horizontal electric field type liquid crystal display panel according to the present invention, a highly reliable horizontal electric field type liquid crystal display panel in which damage due to substrate cracking is suppressed is provided. Can be provided.

10A, 10B: Liquid crystal display panel 10AM, 10BM: Bonded mother substrate 1
0AS, 10BS: strip-shaped mother substrate 11: array substrate 12: transparent substrate 12a:
Overhang 13: Structure 14: Color filter substrate 14M: Second mother substrate 15
: Transparent substrate 16: Structure 17: Conductive film 18: Peripheral sealing material 18a: Panel sealing material 18b: Annular sealing material 19: Liquid crystal injection port 20: Sealing material 21: Driver IC
22: Display area 23: Liquid crystal 24: Seal dispenser 25: Liquid crystal display panel forming area 28: First dividing line 32: Second dividing line

Claims (7)

In the method of manufacturing a horizontal electric field type liquid crystal display panel,
A first step of preparing a first mother substrate and a second mother substrate on which a plurality of liquid crystal display panel regions are formed;
A second sealant is applied to at least one surface of the first mother substrate and the second mother substrate in an annular shape along an outer periphery, and a sealant is applied around each of the plurality of liquid crystal display panel formation regions. And the process of
A third step of bonding the first mother substrate and the second mother substrate in a vacuum;
A fourth step of forming a conductive film in a vacuum on the back surface of one mother substrate of both the bonded mother substrates;
Dividing the mother substrate into liquid crystal display panels;
A method of manufacturing a horizontal electric field type liquid crystal display panel. The step of dividing the mother substrate into each liquid crystal display panel includes:
A fifth step of dividing the bonded mother substrate into a strip shape in a vacuum;
A sixth step of dividing the strip-shaped mother substrate into liquid crystal display panels;
The method of manufacturing a horizontal electric field type liquid crystal display panel according to claim 1, comprising: The step of applying a sealing material around each of the plurality of liquid crystal display panel formation regions in the second step is a step of forming a liquid crystal injection port for each liquid crystal display panel region,
3. The method of manufacturing a horizontal electric field type liquid crystal display panel according to claim 2, further comprising a liquid crystal injection step and a liquid crystal injection port sealing step between the fifth step and the sixth step. The step of applying a sealing material around each of the plurality of liquid crystal display panel forming regions in the second step is a step of applying a sealing material in an annular shape for each liquid crystal display panel region,
3. The method of manufacturing a horizontal electric field type liquid crystal display panel according to claim 2, further comprising a step of dropping and injecting liquid crystal between the second step and the third step. 5. The method of manufacturing a horizontal electric field type liquid crystal display panel according to claim 1, wherein the third step is performed by rigid pressing in a vacuum. The vacuum pressure reduction condition for bonding the both mother substrates in the third step is as follows:
6. The method of manufacturing a horizontal electric field type liquid crystal display panel according to claim 1, wherein the pressure reducing conditions are the same as those in the vacuum process for forming the conductive film in the fourth step. A horizontal electric field type liquid crystal display panel manufactured by the manufacturing method according to claim 1.

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