JPH112822A - Liquid crystal display device and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the liquid crystal display device which prevents resin as a sealing material from spreading from specific line width, hold the cell gap of an area-increased liquid crystal layer at a constant value on the whole, and has improved production efficiency and high display quality and its manufacture as to a liquid crystal display device which has its screen made large by sticking a connection substrate consisting of small-sized substrates opposite a large-size substrate by using the sealing material. SOLUTION: Two TFT substrates 2a and 2a are stuck together by using the sealing material 3 and spacers 4 formed independently of the same pressure- resisting resin. Those sealing material 3 and spacers 4 are formed with high fineness in one process by using a photomask. The spaces 4 are so formed that they are put in areas of the BM(black matrix) on a CF substrate 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to audio-visual (AV) equipment and office automation (OA).
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device having a large direct-view display screen that can be used in equipment, and more particularly to a liquid crystal display device having a high display quality combined with an active matrix substrate and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, for display devices used in audiovisual equipment and office automation equipment, weight reduction, thinning, low power consumption, high definition, and large display screen (hereinafter referred to as "large") have been proposed. , Large screen)
Is required. Among them, especially for large screens, liquid crystal display (LCD), plasma display (PDP), CRT (Cathode Ray Tube) system, etc.
Various display devices such as an electroluminescence (EL) display device and a light emitting diode (LED) display device are being developed and put to practical use.

[0003] Among them, liquid crystal display devices have the advantages of being significantly thinner (depth) than other display devices, low power consumption, and being easy to be full-colored. It is used in the field, and there is great expectation for a large screen.

However, when the size of the liquid crystal display device is increased, a defective rate caused by a disconnection of a signal line or the like or a defect of a pixel rapidly increases in a manufacturing process. In addition to this, the large screen makes the manufacturing process complicated, and as a result,
There is a problem that the price of the liquid crystal display increases.

Therefore, in order to solve the above problems,
A liquid crystal display device for connecting a plurality of small substrates to each other to increase the screen size has been proposed. Specifically, in the liquid crystal display device having a large screen, at least one substrate of a pair of electrodes with electrodes constituting the liquid crystal display device connects a plurality of small substrates to each other on a side surface thereof. In the form of a single large connection substrate.

In particular, in the case of an active matrix type liquid crystal display device, it is extremely difficult to manufacture an active matrix substrate, which is a substrate on which fine active elements are formed for each pixel, with a large area and a high yield. Therefore, this active matrix substrate is used as a connection substrate that connects a plurality of small substrates. As described above, by using the active matrix substrate, which is difficult to increase in size, as the connection substrate, the efficiency of the liquid crystal display device having a larger screen can be improved in terms of production.

As a liquid crystal display device using the above-described connection substrate, a liquid crystal panel disclosed in Japanese Utility Model Laid-Open No. 60-191029, a liquid crystal display device disclosed in Japanese Patent Application Laid-Open No. There are manufacturing methods and the like.

For example, a liquid crystal display device disclosed in Japanese Patent Application Laid-Open No. H8-184849, as shown in FIGS.
Four small substrates 61a are connected in a "-" shape to form one large substrate 61, and the large substrate 61 and the opposing substrate 62 are bonded together via a liquid crystal layer 64 sealed with a sealing material 63. Has become. In this liquid crystal display device, a support member 66 is provided between the connection portion of the small substrate 61a and the non-light-transmitting pattern 65 formed on the counter substrate.

In the manufacturing process of the liquid crystal display device, first, a sealing material 63 and a non-light-transmitting pattern 65 are formed on a counter substrate 62. Next, the small substrates 61a are connected to each other by the adhesive 67. Further, a supporting member 66 made of the same material as the sealing material 63 is formed on the non-light-transmitting pattern 65 at a position corresponding to the connection between the small substrates 61a.

Therefore, the supporting member 66 is formed between the connection portion where the small substrates 61a are connected to each other by the adhesive 67 and the opposing non-translucent pattern 65. The support 66 allows the small substrate 6
It is possible to avoid the adverse effect on the display screen due to the step between 1a and 61a, and it is also possible to avoid a decrease in the non-defective product rate, thereby improving the productivity.

[0011]

However, in the liquid crystal display device and the method of manufacturing the same disclosed in Japanese Patent Application Laid-Open No. H8-184849 or the like, the following are required due to the structure of the liquid crystal display device and the manufacturing process. Show (1) and (2)
Problem occurs.

(1) In the manufacturing process of the liquid crystal display device, a connecting substrate and a large-sized substrate are bonded to each other so as to face each other, and then a cell gap of a liquid crystal layer which is a gap between these substrates is set. Is required. In these steps, in the step of bonding the above substrates while facing each other,
A resin serving as a sealing material is drawn on a portion of the large substrate corresponding to the outer frame region of the small substrate serving as the connection substrate. This sealing material is a member for bonding the above substrates together and enclosing the liquid crystal layer.

[0013] Then, a connection substrate is bonded in accordance with the drawn resin pattern. Thereafter, these substrates are pressed against each other using a pressing device or the like to set a cell gap. After the setting of the cell gap, the uncured resin serving as the sealing material is cured to form the sealing material.

At the time of pressing for setting the cell gap, the drawn resin is not in a cured state. For this reason, the line width of the resin drawn by the above-mentioned press is increased to some extent. in this way,
When the line width of the resin is widened, the spread resin may protrude into the display screen area in the liquid crystal layer.

In particular, between the connecting portions of the small substrates, it is necessary to make the connecting portion as narrow as possible.
This is because, if the connection portion is a wide area, the pixel pitch is disturbed only in the portion of the connection portion on the obtained display screen, so that the connection portion is conspicuous, which causes a sense of incongruity as the entire display screen. .

As described above, the resin protruding into the display screen area is shielded by a non-translucent pattern such as a black matrix (BM). Since the non-light-transmitting pattern becomes a non-display area on the display screen, it is possible to prevent the resin that has overflowed from adversely affecting the display screen. However, in order to shield the protrusion of the resin, it is necessary to widen the area of the non-light-transmitting pattern. When the area of the non-light-transmitting pattern is widened, a problem that the aperture ratio of the pixel decreases is caused.

The decrease in the aperture ratio of the pixel darkens the entire display screen and lowers the contrast. In order to suppress the decrease in contrast, there is a means for increasing the brightness of the backlight. However, this means is not preferable because the power consumption of the backlight increases and the power consumption of the entire liquid crystal display device also increases.

Further, the resolution of the display screen of the liquid crystal display device having the reduced aperture ratio of the pixels is lower than that of a normal liquid crystal display device having a display screen of the same size.

Normally, a non-display area between pixels is set to have a width that can include a pattern of two seal materials and a connection margin. Therefore, a non-display area having a certain area is required in one pixel. However,
In order to increase the resolution, the area per pixel must be reduced. On the other hand, the area of the non-display area is constant regardless of the area of the pixel. Therefore, in the liquid crystal display device having the above configuration, if the resolution is increased by reducing the area of the pixel, the ratio of the area of the non-display area to the area of the pixel becomes relatively large. As a result, the aperture ratio of the pixel is further reduced.

Therefore, in a liquid crystal display device which enlarges the screen by connecting a plurality of small substrates, it is impossible to improve the display quality of the liquid crystal display device unless the decrease in the aperture ratio is suppressed as described above. The problem is that it is difficult. In order to solve this problem, it is necessary to suppress the resin serving as a sealing material from expanding from a predetermined line width, particularly at a connection portion between the small substrates.

(2) As the screen size of the liquid crystal display device increases, the area of the liquid crystal layer sandwiched between the connection substrate and the large substrate also increases. For this reason, the cell gap of the liquid crystal layer, which is the increased thickness of the liquid crystal layer, is insufficient to maintain a constant value in the entire liquid crystal layer.

If the maintenance of the cell gap becomes insufficient, the liquid crystal tends to be unevenly distributed in the lower part of the display screen due to the weight of the liquid crystal itself in the liquid crystal layer. The uneven distribution of the liquid crystal causes a problem that display unevenness occurs on the display screen.

As described above, in the conventional liquid crystal display device, since each of the problems (1) and (2) has occurred,
Enlarging the screen of a liquid crystal display device while maintaining high display quality is still insufficient.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a large screen by bonding a connecting substrate composed of a plurality of small substrates to a large substrate with a sealing material and bonding them together. In the liquid crystal display device, it is possible to prevent the resin serving as the sealing material from spreading from a predetermined line width and maintain the cell gap of the liquid crystal layer having a large area as a whole at a constant value. An object of the present invention is to provide a liquid crystal display device having improved display efficiency and high display quality, and a method for manufacturing the same.

[0025]

According to a first aspect of the present invention, there is provided a liquid crystal display device comprising: a large-sized substrate having a matrix-like non-light-transmitting pattern; In a liquid crystal display device in which a single connection substrate formed by connecting a small substrate at a side portion thereof and a liquid crystal layer is sandwiched therebetween, a sealing material for bonding the large substrate and the connection substrate is provided. The large-sized substrate and the spacer for maintaining the thickness of the liquid crystal layer sandwiched between the connection substrates at a predetermined value are made of a resist having a pressure resistance.

According to the first aspect of the present invention, since the sealing material and the spacer are made of a resist, when setting the cell gap by pressing the large substrate and the connection substrate facing each other, The resist serving as a sealing material can be in a cured state. Due to the cured resist, the resist is pressed during the above-mentioned pressing step and spreads from a predetermined line width, so that the formation region of the sealing material does not protrude into the display screen region. That is, the sealing material made of the resist has a stable shape in which the shape of the sealing material does not change more than necessary in the manufacturing process of the liquid crystal display device.

Further, since the sealing material is made of a resist, the sealing material can be formed with high definition. For this reason, in the connection portion between the small substrates,
The sealant can be formed closer to the display screen area. Therefore, it is possible to avoid widening the area of the non-light-transmitting pattern in the connection portion in order to shield the resin (resist in this case) serving as a sealing material.

Therefore, in the obtained liquid crystal display device, a decrease in the aperture ratio of the pixel is avoided, and the contrast and the resolution of the display screen can be increased. As a result, it is possible to provide a large-screen liquid crystal display device having a high display quality and inconspicuous connection portions.

Further, since not only the sealing material but also the spacer is made of a resist, the sealing material and the spacer are formed by a developing pattern using a photomask.
It can be formed in a process and with high definition. In particular, the spacer can be formed so as to be shielded by the non-translucent pattern on the display screen and to fit within the region of the non-translucent pattern. Therefore, the spacer does not have any effect on the display screen.

As a result, a larger number of spacers than before can be formed at a stable position without affecting the display screen. Therefore, as the size of the liquid crystal display device is increased, the area of the liquid crystal layer is increased, and even if it is difficult to maintain the cell gap of the liquid crystal layer as a whole uniformly, a sufficient number of liquid crystal layers are required. Spacers can be formed. Thereby, the uneven distribution of the liquid crystal downward due to the insufficient maintenance of the cell gap can be suppressed, and a high-quality liquid crystal display device without display unevenness can be obtained.

According to the liquid crystal display device of the present invention,
In order to solve the above problem, in addition to the configuration described in claim 1, the resist has an adhesive property.

According to the second aspect of the present invention, since the resist has an adhesive property, the connection substrate and the large-sized substrate are bonded not only with the sealing material but also with the spacer. Therefore, the bonding structure in which the substrates face each other is further stabilized, and the cell gap can be sufficiently maintained even in a large-area liquid crystal layer.

The resist does not protrude from a predetermined area, but is hardened in a state having plasticity enough to be slightly crushed by a press. Therefore, the resist slightly crushed by the press can increase the bonding area between the opposing substrates and improve the bonding strength between the substrates. As a result, the uneven distribution of the liquid crystal downward is further suppressed, and a liquid crystal display device of high quality display without display unevenness can be obtained.

Further, since the resist itself has an adhesive property, in order to bond the above-mentioned substrates to each other, for example, an additional layer of an adhesive is formed on the resist to complicate the manufacturing process. Is avoided. Therefore, the structure of the obtained liquid crystal display device can be simplified, and the manufacturing cost can be reduced.

A liquid crystal display device according to a third aspect of the present invention comprises:
In order to solve the above-described problem, in addition to the configuration described in claim 1 or 2, the spacer is further provided with an adhesive layer.

According to the third aspect of the present invention, even when the resist itself has no adhesiveness, it is possible to impart adhesiveness to the sealing material and the spacer by forming an adhesive layer. Further, even when the resist has adhesiveness, by forming the adhesive layer, the adhesiveness of the sealant and the spacer can be further ensured. Therefore, the structure in which the large-sized substrate and the connection substrate are bonded to each other can be made stronger, and the cell gap of the liquid crystal layer can be maintained more uniformly as a whole.

A liquid crystal display device according to a fourth aspect of the present invention comprises:
In order to solve the above-mentioned problem, in addition to the configuration described in claim 1, 2, or 3, the liquid crystal layer is separated by a sealing material for each of a plurality of small substrates.

According to the structure of the fourth aspect of the present invention, the display screen of the obtained liquid crystal display device does not have a sense of incongruity, that is, the step at the connection between the small substrates does not adversely affect the display screen. Thus, the cell gap of the liquid crystal layer can be controlled for each of the small substrates. In addition, since the area of the liquid crystal layer is small for each small substrate, the uniformity of the entire cell gap is more easily maintained by the spacer made of the resist. This makes it possible to provide a large-screen liquid crystal display device having higher display quality.

According to a fifth aspect of the present invention, there is provided a liquid crystal display device comprising:
In order to solve the above-described problem, in addition to the configuration according to any one of claims 1 to 4, the connection substrate may include a plurality of gaps that fit in a region of the matrix-shaped non-transparent pattern. It is characterized in that it is a substrate formed by connecting two small substrates.

According to the fifth aspect of the present invention, since the sealing material formed at the connection portion is made of a resist, the resist serving as the sealing material spreads out at the connection portion and protrudes into the display screen area. Without,
The pattern of the sealing material can be formed with a finer line width and high definition. Therefore, it is not necessary to increase the area of the non-translucent pattern.

For this reason, the connection portion forms a gap that fits within the area of the non-translucent pattern, so that the pixel pitch on the display screen is made uniform over the entire display screen without lowering the aperture ratio of the pixels. can do. As a result, it is possible to prevent the connection section from adversely affecting the display screen, and to realize a large-screen liquid crystal display device capable of high-quality display.

A liquid crystal display device according to a sixth aspect of the present invention comprises:
In order to solve the above-described problem, in addition to the configuration according to any one of claims 1 to 5, a gap between the plurality of small substrates in the connection substrate is substantially equal to a substrate material of the small substrates. It is characterized by being filled with resins having the same refractive index.

According to the above configuration, the large-sized substrate and the small-sized substrate include the sealing material and the spacer,
This means that the small substrates are bonded together with the adhesive at the connection portion. For this reason, the structure in which the large-sized substrate and the connection substrate are bonded to each other can be made stronger, and in particular, the structure at the connection portion between the small-sized substrates can be made stronger. Therefore, the cell gap of the liquid crystal layer can be maintained more uniformly as a whole.

Since the adhesive has substantially the same refractive index as the substrate material of the small substrate, it is possible to prevent refraction and scattering of light between the small substrates of the connection portion. For this reason, it is possible to prevent the connection section from adversely affecting the display screen.

A liquid crystal display device according to a seventh aspect of the present invention comprises:
In order to solve the above problem, in addition to the configuration according to any one of claims 1 to 6, the resist serving as the spacer and the sealing material is formed on a large-sized substrate. I have.

According to the above configuration, when the resist serving as the sealing material and the spacer is formed on the small-sized substrate, the thickness of the resist may be different due to a step at a connection portion between the small-sized substrates. . On the other hand, by forming a resist on a large substrate, the thickness of the resist becomes constant. For this reason, adverse effects such as a change in color tone due to different thicknesses of the resist can be avoided, and a high-quality display screen with less noticeable connection portions can be realized.

The liquid crystal display device according to claim 8 of the present invention,
In order to solve the above problem, a pair of substrates with electrodes are attached to each other so as to face each other, and a liquid crystal display device including a liquid crystal layer sandwiched between the substrates is provided with a sealing material for attaching the pair of substrates. The spacer for maintaining the thickness of the liquid crystal layer sandwiched between the substrates at a predetermined value is made of a resist having a pressure resistance.

According to the structure of the eighth aspect, since the sealing material and the spacer are made of a resist, the sealing material and the spacer are formed in one step and with high definition by a development pattern using a photomask. be able to. Therefore, the spacers can be easily formed so as to fit within the non-display pattern region, and the number of spacers capable of sufficiently maintaining the cell gap can be formed without adversely affecting the display screen. Therefore, it is possible to stabilize the structure of the obtained liquid crystal display device and to avoid a decrease in display quality due to uneven distribution of liquid crystal.

According to a ninth aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, wherein a sealing material and a spacer are provided on a large-sized substrate having a matrix-like non-light-transmitting pattern. Forming a predetermined pattern in a state where the resist is cured, and forming a single connection substrate such that a plurality of small substrates are adjacent to side surfaces of a large substrate on which the resist is formed. The thickness of the space sandwiched between the large-sized substrate and the connection substrate is set to a predetermined value by pressing the small-sized substrate and the large-sized substrate and the connection substrate facing each other. And a process.

According to the manufacturing method of the ninth aspect, when each of the substrates is pressed for setting a cell gap,
The sealing material and the spacer are formed as a cured resist. By this curing, the shape of the resist becomes stable. Therefore, by pressing the substrates, the resist serving as the sealing material is prevented from spreading from a predetermined line width and protruding into the display screen area. Similarly, the spacer also extends from the predetermined area, and does not protrude from the non-light-transmitting pattern to the display screen area, for example. Therefore, the area of the non-light-transmitting pattern that shields these sealing materials and spacers is increased,
It is not necessary to consider the protrusion of the sealing material and the spacer. Therefore, the aperture ratio of the pixel can be improved.

In addition, the resist serving as the sealing material and the spacer can be formed in one step by a development pattern using a photomask. For this reason, complication of the manufacturing process can be avoided, and the manufacturing process can be simplified.

Further, in the above manufacturing method, when bonding the connection substrate to the large substrate, a plurality of small substrates are bonded to the large substrate first and then connected. For this reason, when connecting small substrates first and bonding them to a large substrate, the structure of the connection substrate does not become unstable due to the small area of the connection portion between the small substrates. Therefore, it is possible to avoid complication of the manufacturing process, such as requiring care in handling the connection substrate.

According to a tenth aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device according to the ninth aspect, further comprising the step of bonding to a surface in contact with the large-sized substrate. The method includes a step of transferring and forming an adhesive layer on the resist by bonding a transfer substrate coated with an agent so as to face the large substrate.

According to the manufacturing method of the tenth aspect,
By pressing the transfer substrate and the large-sized substrate on which the resist is formed, the adhesive can be formed only by transferring the adhesive layer, so that the manufacturing process is not complicated.

In order to solve the above-mentioned problems, a method for manufacturing a liquid crystal display device according to claim 11 of the present invention is characterized in that, in the manufacturing method according to claim 9 or 10, the substrates facing each other are subjected to atmospheric pressure. It is characterized by being pressed by.

According to the manufacturing method of the eleventh aspect,
In the case where the large-sized substrate and the small-sized substrate are bonded to each other, the substrates can be bonded to each other with a substantially uniform cell gap as a whole including the connection surfaces of the small-sized substrates. Therefore, the cell gap of the liquid crystal layer of the obtained liquid crystal display device can be made more uniform as a whole. In addition, even when the above adhesive layer is transferred, the large substrate and the transfer substrate can be pressed more uniformly as a whole. Therefore, the transferred adhesive layer can be made more uniform.

[0057]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.
Note that the present invention is not limited by this.
As shown in FIG.
One large substrate (hereinafter, referred to as a CF substrate) 1 and an active matrix substrate (hereinafter, referred to as a TFT substrate) 2a as a small substrate using a TFT as an active element 2a are connected on one side by one side. The substrate 2 is bonded to the sealing material 3, the spacer 4, and the adhesive 5 at a connection portion between the TFT substrates 2 a and 2 a.

Along the edge of each of the TFT substrates 2a,
Each of the TFT substrates 2a and the CF substrate 1 are bonded to each other with a sealing material 3. Therefore, the sealing material 3 is C
This means that the TFT substrates 2a are independently attached to the F substrate 1. Therefore, the liquid crystal layer 1
4 are individually sandwiched between each TFT substrate 2a and the CF substrate 1.

The sealing material 3 and the spacer 4 are made of CF.
It is formed on a substrate 1. The spacer 4 and the sealing material 3 at the connection portion are formed by a black matrix (hereinafter, referred to as B
M) 12 are formed. In addition, as shown in FIG. 2, an opening 15 for injecting a liquid crystal is formed in the pattern of the sealing material 3.

As shown in FIG. 2, pixels 6 are formed in a matrix on the TFT substrate 2a, and one pixel 6 includes red (R), green (G), and blue (B). Three pixel electrodes 7 corresponding to the color filters are arranged.

The TFT substrate 2a shown in FIGS. 1 and 2 will be described in more detail. As shown in FIG. 3, a TFT 8 as an active element is formed on each pixel electrode 7, and the pixel electrode 7 is The scanning lines 9 and the signal lines 10 for driving are formed so as to cross each other. Further, on the CF substrate 1, each color filter (hereinafter, referred to as CF) 11, BM 12, and common electrode 13 are formed.

The connection between the TFT substrates 2a and 2a is shown in FIG.
As shown in FIG. 5, an adhesive 5 which is a resin having substantially the same refractive index as the substrate material of the TFT substrate 2a is filled.
Then, a layer made of the sealing material 3 is formed so as to contact both sides of the layer made of the adhesive 5. The adhesive 5 is formed so as to connect the two TFT substrates 2 a and 2 a on the side surfaces thereof and also to contact the CF substrate 1.

That is, the two TFT substrates 2a and 2a and C
The F substrate 1 includes, in addition to the sealing material 3 and the spacer 4,
It is also bonded at the connection portion by an adhesive 5. At this time, the layer of the adhesive 5 and the layer of the sealing material 3 at the connection portion are formed so as to form a gap that fits in the region of the BM 12 on the CF substrate 1 facing the connection portion.

More specifically, as shown in FIG. 4, in the connection portion, the sealing material 3 and the adhesive 5 layer of the connection portion do not overlap the three pixel electrodes 7 constituting the pixel 6. It is formed as follows. That is, the BM 12 formed on the CF substrate 1 is a non-display area that does not overlap the pixel electrode 7. Therefore, the sealing material 3 and the adhesive 5
Is formed so as to fit within the region of the BM 12, it is possible to avoid that the layer composed of the sealing material 3 and the adhesive 5 adversely affects the display screen of the obtained liquid crystal display device.

For example, in the connection section, the BM12
Is W, the width of the layer made of the adhesive 5 is M, and the width of the layer made of the sealing material 3 is N. In this case, the sum M + 2N of the widths of the layers formed of the sealing material 3 and the adhesive 5 forming the connection portions of the TFT substrates 2a and 2a is M + 2 when compared with the width W of the BM 12.
2N <W.

As the TFT substrate 2a, for example,
A glass substrate made of non-alkali glass (such as Corning 7059) can be used. In the present embodiment,
Although two TFT substrates 2a are used, the connection is made by forming the layer made of the sealing material 3 and the layer made of the adhesive 5 as described above at the connection portion between the TFT substrates 2a. If so, three or more sheets may be used. For example, when the TFT substrate 2a is
One connection board 2 can be formed by the connection.

As the adhesive 5, it is preferable to use a transparent adhesive having a refractive index substantially equal to that of the glass substrate used for the TFT substrate 2a. Specifically, an ultraviolet curable adhesive is often used. The ultraviolet curable adhesive is a glass substrate used for the TFT substrate 2a (in the case of Corning 7059, the refractive index is 1.
One having a refractive index substantially equal to 53) can be easily obtained.

For this reason, refraction and scattering of light can be prevented in the gap between the two TFT substrates 2a, and the adverse effect on the display screen due to coloring of the light transmitted through the connection portion can be avoided. In addition, since no heat is required at the time of curing, adverse effects of heat on the TFT substrate 2a and the CF substrate 1 can be avoided.

By the way, the resin conventionally used as the sealing material 3 spreads from a predetermined line width when the connection substrate 2 composed of the TFT substrates 2a and the CF substrate 1 are bonded and pressed. Has problems.
As described above, when the resin spreads from a predetermined line width, the resin protrudes into the display screen area, and adversely affects the display screen. Therefore, in order to shield the protruding resin by the BM 12, the width W of the BM 12 is increased at the connection portion in consideration of the protruding resin.

However, the BM1 at the connection section
When the width W of the pixel 2 is increased, the aperture ratio of the pixel 6 decreases. This is because the BM 12 is a non-display area on the display screen. Therefore, if the width W of the BM 12 in the connection portion is increased, the BM 12 forms one pattern on the entire display screen.
This is because the entire area of M12 is widened. If only the connection portion is a BM 12 having a wide width, the connection portion is conspicuous on the display screen, giving an uncomfortable feeling to the entire display screen. Such a decrease in the aperture ratio causes a decrease in display quality such as a decrease in contrast by darkening the entire display screen or a decrease in resolution of the display screen.

Therefore, in the liquid crystal display device of the present invention, the above problem is prevented by using a resist having a pressure resistance as the resin for the sealing material 3. The resist is made of the same material as that of the spacer 4 as described later. The resist itself has an adhesive property, or the connection substrate 2 and the CF substrate are formed by forming an adhesive layer on the resist. 1 can be attached.

Further, after the CF substrate 1 and the connection substrate 2 are bonded together, at the time of pressing for setting the cell gap, the resist serving as the sealing material 3 can be in a cured state. Since the cured resist is formed in a stable state, the line width of the resist is increased at the time of the pressing, and the resist is prevented from protruding into the display screen area.

As a result, the TFT substrate 2 shown in FIG.
a · 2a, the width N of the seal material 3 is BM
In the area that fits within the width W of 12, the image can be unevenly distributed to a position close to the display screen area. Therefore, it is not necessary to increase the width W of the BM 12, which is a non-display area, in consideration of the protrusion of the resin serving as the sealing material 3.

Therefore, in the liquid crystal display device of the present embodiment, even when the TFT substrates 2a and 2a are connected to increase the screen size, unlike the related art, the BM pattern normally used as the BM 12 is different from that of the conventional BM. It is possible to use one having substantially the same pattern. Therefore, a decrease in the aperture ratio of the pixel 6 is avoided.

As described above, since the aperture ratio of the pixel 6 does not decrease, the resolution of the obtained display screen can be increased, and a decrease in contrast can be avoided. Therefore, it is possible to avoid an increase in power consumption of the liquid crystal display device such as increasing the brightness of the backlight.

When a resist is used as the sealing material 3, a predetermined pattern of the sealing material 3 can be formed with high definition. Therefore, in the connection portion, the width N of the sealing material 3 can be unevenly distributed to a limit position close to the display screen region within a region that fits within the width W of the BM 12. Therefore, it is easier to set the pixel pitch in the connection portion to be the same as the pixel pitch in the other region than in the related art. This avoids the connection portion between the two TFT substrates 2a and 2a from adversely affecting the display screen, and enables a large display screen without a sense of incongruity for the viewer.

In addition, the connecting portion is formed so as to fit within the width W of the BM 12, and the connecting portion has a TF.
An adhesive 5 having substantially the same refractive index as the substrate material of the T substrate 2a is filled. For this reason, the connection portion is suppressed from being conspicuous on the obtained display screen.

Further, the liquid crystal layer 14 is formed on the TFT substrate 2
a for each TFT substrate 2 a so that the entire display screen does not feel uncomfortable.
4 can be controlled. Therefore, even in the case where a step occurs in the above-mentioned connection portion,
The adverse effect on the display screen can be avoided.

As described above, the spacer 4 is made of the same material as the sealing material 3 such as resist.
It is formed so as to fit within the area of the BM 12 on the CF substrate 1. The spacer 4 is composed of the CF substrate 1 and the connection substrate 2
And the cell gap, which is the thickness of the liquid crystal layer 14 sandwiched between them, is kept constant.
It has a function of bonding the substrates 2a and 2a to the CF substrate 1.

The resist has a pressure resistance as described above. This is because it is necessary to maintain the thickness of the cell formed as the spacer 4 sandwiched between the CF substrate 1 and the TFT substrates 2a, 2a, that is, the cell gap of the liquid crystal layer 14 at a predetermined value. As the resist, for example, a UV-curable resist having pressure resistance can be used.

As the spacer 4, a two-layer structure having an adhesive layer for bonding the CF substrate 1 and the TFT substrates 2a on the resist can be used. Further, the structure may be a single-layer structure made of a resist having an adhesive property. as mentioned above,
Since the spacer 4 has adhesiveness, the spacer 4
Has a function of bonding the two TFT substrates 2 a and 2 a and the CF substrate 1 together with the sealing material 3.

Therefore, the CF substrate 1 and the TFT substrate 2a
2a means that not only the sealing material 3 but also the spacer 4 is attached. The material of the spacer 4 and the sealing material 3 is limited to the above-mentioned resist only as long as it can be formed with high definition, has a pressure resistance, and has an adhesive property capable of bonding the above substrates. Not something.

Here, bead spacers made of resin or silica have been often used as the spacers. These bead-shaped spacers have extremely small diameters (about the same diameter as the cell gap of the liquid crystal layer). For example, if the cell gap of the liquid crystal layer is 5 μm, a diameter of about 5 μm is used. . Therefore, the viewer cannot see the spacer on the display screen, and there is almost no adverse effect on the display screen. Therefore, the spacers are scattered almost randomly over the display screen area of the liquid crystal layer so as to have a uniform density.

At this time, as the number of spacers increases, the cell gap of the entire liquid crystal layer can be maintained more uniform.
However, in the liquid crystal layer, since no liquid crystal exists in the spacer portion, the display screen is always white regardless of the driving state of the liquid crystal, and the level of black display is slightly reduced. Therefore, the contrast of the obtained display screen is reduced.

Therefore, the number of spacers to be scattered needs to be limited, although it is not confirmed by the viewer on the display screen. However, when the number of spacers is limited, it is insufficient to maintain a uniform cell gap as the entire liquid crystal layer. In particular, in a liquid crystal display device having a large display screen, if the cell gap of the entire liquid crystal layer cannot be maintained, the liquid crystal is unevenly distributed below the display screen due to the weight of the liquid crystal itself, causing display unevenness. Will have an adverse effect.

On the other hand, in the liquid crystal display device of the present embodiment, since the spacer 4 is made of a resist, it can be formed at a specific position with high definition. Therefore, the spacers 4 can be accurately formed so as to fit within the non-display area BM 12 formed on the CF substrate 1. Therefore, CF substrate 1 and T
Between the FT substrates 2a, 2a, a sufficient number of spacers 4 capable of maintaining the cell gap of the liquid crystal layer 14 more uniformly can be formed without affecting the display screen at all.

The shape of the spacer 4 is BM12
The size is not particularly limited as long as the size can fit within the area. Specifically, the shape of the spacer 4 is BM1
A line pattern along the BM 12 with a line width that fits within the region 2 may be used. Alternatively, an island-shaped pattern in which pillar-shaped resist layers are formed at regular intervals in a region shielded by the BM 12 may be used. At this time, the pattern of these spacers 4 is
Each TFT substrate 2a needs to be formed such that the occupied area of the spacer 4 per unit pixel area is substantially the same.

Spacer 4 made of resist as described above
Is shielded by a non-translucent pattern on the display screen, so that the spacer 4 does not adversely affect the display screen. As a result, a larger number of spacers 4 than before can be formed at a stable position without affecting the display screen. Therefore, the cell gap can be sufficiently maintained even in the liquid crystal layer 14 having a large area.

Further, the spacer 4 bonds the CF substrate 1 and the TFT substrates 2a together with the sealing material 3. For this reason, compared with the conventional liquid crystal display device, the substrates are uniformly bonded not only at the peripheral portion of each substrate but also over the entire display screen area of the liquid crystal layer. In addition, as described above, the gap between the connection portions of the TFT substrates 2a is filled with the adhesive 5 so as to be in contact with the CF substrate 1. Therefore, the CF substrate 1 and the connection substrate 2 are separated from each other by the sealing material 3, the spacer 4 and the adhesive 5.
Will be bonded together.

Therefore, in the liquid crystal display device of the present embodiment in which the CF substrate 1 and the connection substrate 2 are bonded, the cell gap of the liquid crystal layer 14 is stronger than that of the conventional liquid crystal display device having a large screen. The structure is maintained.
Therefore, the cell gap of the liquid crystal layer 14 is also maintained more uniformly as a whole, and even in a liquid crystal display device having a large display screen,
The uneven distribution of the liquid crystal downward can be suppressed by the weight of the liquid crystal itself. Therefore, it is possible to provide a display screen with high display quality without display unevenness.

Further, in the present embodiment, the liquid crystal layer 14 is formed independently for each of the TFT substrates 2a. Therefore, the area of the liquid crystal layer 14 does not become extremely large even as the screen size of the liquid crystal display device increases. Therefore, in the liquid crystal layer 14, the uniformity of the entire cell gap is more easily maintained. This makes it possible to provide a large-screen liquid crystal display device having higher display quality.

In addition, the sealing material 3 and the spacer 4
Is formed on the CF substrate 1 which is a large substrate. This is to make the connection between the TFT substrates 2a less noticeable.

For example, the above resist is applied to the TFT substrate 2a.
-When formed on 2a, the thickness of the resist may be different at the connection between the TFT substrates 2a. That is, if there is a slight step or gap at the connection between the TFT substrates 2a, the thickness of the resist formed at this connection is affected.

In particular, if the thickness of the resist serving as the sealing material 3 differs by 0.3 μm or more, the cell gap of the liquid crystal layer 14 will change significantly at the connection. Such a large change in the cell gap is caused by the TFT substrate 2a on the display screen.
Since the color change of the connection portion 2a occurs, the connection portion becomes conspicuous.

On the other hand, when a resist is formed on the CF substrate 1, no step is generated by connecting the small substrates as described above, so that a difference in the thickness of the resist is avoided. Therefore, the connection portion is prevented from being conspicuous, and a higher-quality display screen can be realized.

The liquid crystal display device of this embodiment having the above configuration has no display unevenness on the display screen and has a high aperture ratio. Further, even if the screen is enlarged by connecting the small substrates, the connection portion between the small substrates is conspicuous, and the whole display screen does not feel strange. Therefore, it is possible to provide a liquid crystal display device having a large display screen with a higher display quality than before.

The above configuration can be suitably applied when the arrangement of the pixels 6 is a stripe arrangement. In the case where the arrangement of the pixels 6 is a delta arrangement, since the region of the BM 12 is not linear, it is difficult to apply the above configuration.

Next, a method for manufacturing the liquid crystal display device of the present invention will be described. The method for manufacturing a liquid crystal display device of the present invention includes:
As shown in FIG. 5, the method has the following six basic steps.

First, the first step (P1; hereinafter, the step is referred to as P
(Abbreviated as)), a layer of a resist serving as a sealing material 3 and a spacer 4 is applied on the CF substrate 1. Then, using a photomask having a predetermined pattern, the resist layer is exposed and developed, and a resist serving as a sealing material 3 and a spacer 4 is simultaneously formed on the CF substrate 1 as a predetermined pattern.

At this time, when an adhesive layer is further formed on the resist serving as the sealing material 3 and the spacer 4, the resist is completely cured by post-baking. In the case of using only an adhesive resist that does not form an adhesive layer, it is temporarily cured at a glass transition temperature or lower. In any case, when the process moves from P1 to the next step, the resist is in a hardened state.

Next, as a second step (P2), an alignment film is formed on each of the opposing surfaces of the CF substrate 1 and the plurality of TFT substrates 2a (two in this embodiment).

Then, as a third step (P3), each of the connection substrates 2 is formed such that a plurality of TFT substrates 2a are adjacent to the CF substrate 1 on the side surfaces thereof to form one connection substrate 2. And stick them together. At this time, it is necessary to bond two TFT substrates 2a so as to correspond to the resist formed as a predetermined pattern on the CF substrate 1.

Next, as a fourth step (P4), the thickness of the space sandwiched between the CF substrate 1 and the TFT substrates 2a, that is, the cell gap in the liquid crystal layer 14 is set to a predetermined value. Press to Then, the facing state of each substrate is fixed by hardening the adhesive layer formed on the resist or by fully hardening the resist in a temporarily hardened state.

At this time, the hardened resist is about 0.1 mm.
It has a strength of 7 kg / cm ² . In order for the resist to be hardly crushed even by pressing, the strength of the resist needs to be about 1.0 kg / cm ² . However, in the above P4, since the press is performed for setting the cell gap, it is necessary to change the cell gap by slightly crushing the resist by the press. Therefore, in the above-mentioned cured resist, it is preferable that the strength is set slightly lower as described above.

Further, as a fifth step (P5), an adhesive 5 having substantially the same refractive index as the substrate material of the TFT substrate 2a is filled in the gap between the connection portions of the plurality of TFT substrates 2a. .

Finally, as a sixth step (P6), the opening 15 previously formed in the pattern of the sealing material 3 is formed.
The opening 15 is sealed with a sealing material, and the liquid crystal display device having a large display screen of the present invention is manufactured.

In the above manufacturing method, in P1, the resist to be the sealing material 3 and the spacer 4 can be formed in one step by a development pattern using a photomask. Therefore, both the pattern of the spacer 4 and the pattern of the sealing material 3 can be disposed on the CF substrate 1 at a time on the photomask. for that reason,
The manufacturing process of the liquid crystal display device can be simplified.

Further, in the above manufacturing method, when bonding the connection substrate 2 to the CF substrate 1, a plurality of TFT substrates 2a are bonded to the CF substrate 1 first in P3 and then connected in P5. . For this reason, the structure of the connection substrate 2 becomes unstable due to the small area of the connection portion between the TFT substrates 2a, so that it is possible to avoid complication of the manufacturing process such that the handling of the connection substrate 2 requires attention.

In addition, in the above P4, when the inside of the cell to be the liquid crystal layer 14 is depressurized from the opening for injecting the liquid crystal and the substrates are pressed at atmospheric pressure, the uniformity can be obtained even in a large area. Press is possible. This pressing method using the atmospheric pressure is preferable because the cell gap can be made uniform as a whole when the cell gap of the liquid crystal layer 14 is set to a predetermined value.

The formation of the alignment film of P2 must be performed before the bonding of the substrates in P3. However, the order is not particularly limited. May be performed before is formed.

As described above, the sealing material 3 and the spacer 4 formed in the above P1 have a single-layer structure composed of only a resist, and have a structure in which an adhesive layer is further formed on the resist. It may have a layered structure. As these forming methods, for example, the following methods can be used.

(1) A resist (for example, a UV-curable resist) is applied on the CF substrate 1 and is exposed and developed using a photomask to form a resist having a predetermined pattern. Next, the resist is fully cured by post-baking. Thereafter, the CF substrate 1 on which the resist is formed and the transfer substrate coated with an adhesive on the surface in contact with the CF substrate 1 are bonded to each other by pressing under atmospheric pressure, which will be described later. By bonding the substrates, an adhesive layer is transferred and formed on the resist. Thus, the sealing material 3 and the spacer 4 having a two-layer structure including the resist and the adhesive layer are formed.

(2) A resist having an adhesive property is applied on the CF substrate 1, and the resist is temporarily cured at a temperature equal to or lower than the glass transition temperature of the resist. Thereafter, the temporarily cured resist is exposed and developed using a photomask to form a resist having a predetermined pattern. Further, the CF substrate 1 and the TFT substrates 2a, 2a are bonded together by the adhesiveness (viscosity) of the temporarily cured resist. Thereafter, the temporarily cured resist is post-baked at a temperature equal to or higher than the glass transition temperature, so that the resist is fully cured. By this main curing, the spacer 4 made of only the resist is formed.

Here, in the spacer 4 having the above-described two-layer structure, the adhesive layer formed on the resist is
By pressing the transfer substrate and the CF substrate 1 on which the resist is formed, the transfer substrate can be formed only by transferring. Therefore, complication of the manufacturing process is avoided. The pressing method at this time is also preferably a pressing method using atmospheric pressure because the adhesive layer can be uniformly transferred onto the resist.

In the spacer 4 having a two-layer structure,
The resist does not need to have an adhesive property, but may have an adhesive property. Even if the resist has an adhesive property, the presence of the adhesive layer allows the C
The structure in which the F substrate 1 and the connection substrate 2 are bonded to each other can be further strengthened. Therefore, the cell gap of the liquid crystal layer can be maintained more uniformly as a whole.

In each of the above methods (1) and (2), the cell gap is set in a state where the cell gap is fixed at the atmospheric pressure. That is, in the method (1), after the transfer of the adhesive layer is performed, the CF substrate 1 and the TFT substrates 2a and 2
The cell gap is set in the step of pressing under the atmospheric pressure while facing a. At this time, the resist in the sealing material 3 and the spacer 4 that determines the cell gap has already been cured by post-baking.
Therefore, the sealing member 3 and the spacer 4 do not protrude from the predetermined region even by the above-described pressing process.

On the other hand, in the method (2), the CF substrate 1 and the TFT substrates 2a and 2
and a are bonded together. The bonding of the substrates is performed by the adhesiveness of the resist. Thereafter, the substrates are pressed with each other under the atmospheric pressure, and the temporarily cured resist is post-baked in a state where the substrates pressed opposite to each other are fixed. The state where the substrates face each other is fixed by the post-baking, and the cell gap is set.

Here, the pre-cured resist before pressing is pre-cured at a temperature equal to or lower than the glass transition temperature although it has a viscosity capable of bonding substrates. Therefore, CF
When the substrate 1 and the TFT substrates 2a and 2a are bonded to each other and pressed at atmospheric pressure, the resist serving as the sealing material 3 and the spacer 4 does not protrude from a predetermined region.

Although the temporary curing resist is in a cured state that does not protrude from a predetermined region, it has plasticity enough to be slightly crushed by the press. Therefore, the pre-cured resist formed on the CF substrate 1 is slightly crushed and spread by the press, so that the bonding area with the opposing connection substrate 2 is increased. Therefore, the adhesive strength between the CF substrate 1 and the connection substrate 2 can be improved.

The structures of the sealing material 3 and the spacer 4 are not limited to the above (1) and (2), and may have a multilayer structure of three or more layers including a layer made of another material if necessary. It may be.

As described above, in the manufacturing method of the liquid crystal display device of the present invention, the resist having the pressure resistance, which becomes the sealing material 3 and the spacer 4, is developed in one step by a development pattern using a photomask. It can be formed finely. Therefore, the manufacturing process of the liquid crystal display device can be simplified, and the manufacturing cost can be reduced.

The resist serving as the sealing material 3 and the spacer 4 can be cured when the CF substrate 1 and the connection substrate 2 including the TFT substrates 2a and 2a are bonded. Therefore, even if the respective substrates are pressed with each other at atmospheric pressure or the like, it is possible to prevent the resist serving as the sealing material 3 and the spacer 4 from spreading out from a predetermined line width.

Further, the resist can be formed with high definition by a development pattern using a photomask.
Therefore, at the connection between the TFT substrates 2a,
The seal material 3 can be formed closer to the display screen area, and the spacer 4 can be formed so as to fit within the area of the BM 12 which is a non-light-transmitting pattern.

Therefore, the connection ratio between the TFT substrates 2a is not noticeable without lowering the aperture ratio of the obtained liquid crystal display device. Further, the cell gap can be easily maintained as a whole as compared with the related art. Therefore, a liquid crystal display device having a large display screen with high display quality can be provided at a lower cost without complicating the manufacturing process.

The above-described steps are the minimum basic steps required for manufacturing the above-described liquid crystal display device of the present embodiment. Depending on the type of the liquid crystal display device, various steps other than the above can be appropriately added.

The structure of the liquid crystal display device of the present invention and the method of manufacturing the same are not limited to those having a large screen by connecting a plurality of small substrates, but a liquid crystal display comprising one TFT substrate. The present invention can be applied to a display device.

More specifically, as shown in FIG. 9, a pair of substrates with electrodes, in this case, a CF substrate 31 and a TFT substrate 3
2 and a liquid crystal display device sandwiching the liquid crystal layer 35 one by one, respectively, in a liquid crystal display device, a sealing material 33 for bonding the substrates together and enclosing the liquid crystal layer 35, In this configuration, the spacer 34 for maintaining the cell gap is made of a resist having the same pressure resistance. At this time, the spacer 34 is formed so as to fit within the region of the BM 36 which is a matrix non-light-transmitting pattern.

As described above, the sealing material 33 and the spacer 34
Is made of a resist, the sealing material 33 and the spacer 34 are used as a development pattern using a photomask.
Can be formed in one step and with high definition. Therefore, the spacers 34 can be easily formed at positions where they can be shielded by the BM 36, and the number of spacers 34 that can sufficiently maintain the cell gap can be formed without adversely affecting the display screen.

Therefore, it is possible to stabilize the structure of the obtained liquid crystal display device and to avoid a decrease in display quality due to uneven distribution of liquid crystal. As a result, a high-quality liquid crystal display device can be provided at low cost without complicating the manufacturing method.

Further, according to the structure of the liquid crystal display device of the present invention and the method of manufacturing the same, a plurality of liquid crystal panels in which a pair of substrates with electrodes are opposed to each other and bonded together via a liquid crystal layer are connected to increase the screen size. The present invention can also be suitably applied to a multi-panel type liquid crystal display device for achieving the above.

[0131]

Next, a specific example of a method for manufacturing a liquid crystal display device according to the present invention will be described with reference to FIGS. For convenience of description, FIGS. 6 to 8 show the resist serving as the sealing material 3 so as to have a wider line width than actual.

Embodiment 1 First, as shown in FIG. 6A, a UV-curable resist having a pressure resistance (this embodiment) is formed on a CF substrate 1 on which at least CF, BM, and a common electrode (not shown) are formed. In this embodiment, a negative type) was applied to form a resist layer 4a. Thereafter, exposure and development are performed using a photomask, and further, the CF substrate 1 on which the resist layer 4a is formed is heated by an oven and post-baked, so that the sealing material 3 is formed as shown in FIG. The hardened resist 4c to be formed and the hardened resist 4d to be the spacer 4 were formed (P1).

At this time, the pattern of the cured resist 4c corresponds to the shape of the two TFT substrates 2a and 2a, and has a pattern in which an opening (not shown) for injecting liquid crystal in a later step is provided. did. Further, the pattern of the cured resist 4d is the same as that of the BM provided on the CF substrate 1.
And a pattern corresponding to

The cured resist 4c has a width of 100 μm and a thickness of 100 μm.
The width of the cured resist 4c to be the sealing material 3 at the connection between the FT substrates 2a was formed to be 50 μm.
Further, the width of the cured resist 4d was set to 300 μm corresponding to the width of the BM 12. Each of these cured resists 4c
The thickness of 4d is set to be the same as the thickness of the liquid crystal layer 14 formed in a later step, that is, the cell gap.
It was formed to have a thickness of 0 μm.

Thereafter, an alignment film (not shown) is applied to the surfaces of the CF substrate 1 on which the above-described cured resists 4c and 4d are disposed and the TFT substrates 2a and 2a which are bonded to face each other. After firing, a rubbing treatment was performed (P2).

Next, as shown in FIG.
Transfer substrate 20 coated with adhesive layer 4b on substrate 1
Were opposed to each other. After the transfer substrate 20 and the CF substrate 1 were bonded by a vacuum press, the transfer substrate 20 was peeled off. Thereby, as shown in FIG. 6D, the adhesive layer 4 is formed on the cured resists 4c and 4d formed on the CF substrate 1.
b was transferred. By the transfer of the adhesive layer 4b, the sealing material 3 composed of the cured resist 4c and the adhesive layer 4b is formed.
Thus, the spacer 4 composed of the cured resist 4d and the adhesive layer 4b was formed.

As shown in FIG. 7 (a), the two TFT substrates 2a, 2a are placed on the CF substrate 1 on which the sealing material 3 and the spacer 4 are formed. They were placed facing the substrate 1 and bonded together (P3). At this time, the two TFT substrates 2a are respectively adjusted according to the pattern of the sealing material 3 formed in the previous step.
-2a was bonded.

[0138] The two TFT substrates 2a
In the cell formed by the 2a and the CF substrate 1, the pressure inside the cell was reduced through an opening (not shown) provided in the pattern of the sealing material 3. As a result of such reduced pressure, FIG.
As shown in (b), the connection substrate 2 composed of the TFT substrates 2a and 2a and the CF substrate 1 were pressed under atmospheric pressure (P
4).

Through this pressing step, the cell gap of the liquid crystal layer, which is the width of the gap formed between the TFT substrates 2a and 2a and the CF substrate 1, was set to 5.0 μm. When the cell gap reaches a predetermined value by the above pressing process,
These opposed substrates were held at a high temperature. Thereby, the curing of the adhesive layer 4b is promoted, and the CF substrate 1 and the TF
The state of being bonded to the T substrates 2a was completely fixed.

Subsequently, in order to connect the two TFT substrates 2a and 2a bonded to the CF substrate 1, FIG.
As shown in the figure, in the gap between the two TFT substrates 2a, 2a,
The ultraviolet curing adhesive 5 was filled (P5).

Thereafter, as shown in FIG. 7D, liquid crystal is injected from the opening provided in the pattern of the sealing material 3 to form a liquid crystal layer 14 (P6), and the opening is formed by a sealing material (not shown). Was sealed to produce a liquid crystal display device of the present invention.

[Embodiment 2] In the above embodiment 1, the CF
The liquid crystal display device of the present invention was manufactured under the same conditions and steps except that the formation of the alignment film (P2) on the substrate 1 and the TFT substrates 2a and 2a was performed before the formation of the resist layer 4a (P1).

[Embodiment 3] First, as shown in FIG. 8A, on a CF substrate 1 on which at least CF, BM and a common electrode (not shown) are formed, a negative type UV having a pressure resistance and an adhesive property is provided. A resist layer 24a, which is a curable resist, was applied. Thereafter, the CF substrate 1 is placed in an oven and heated at a temperature lower than the glass transition temperature of the resist.
4 was pre-cured.

Next, the temporarily cured resist layer 24a is exposed and developed using a photomask to obtain the resist layer 24a shown in FIG.
As shown in (b), a temporarily cured resist 24c to be the sealing material 3 and a temporarily cured resist 24d to be the spacer 4 were formed (P1). At this time, each of the temporarily cured resists 2
4c and the pattern of the temporary curing resist 24d are the same as those of the first embodiment
And the same pattern as the patterns of the cured resists 4c and 4d.

Thereafter, each of the temporary curing resists 24c and 2c
An alignment film (not shown) was applied to the surfaces of the CF substrate 1 on which the 4d was disposed and the TFT substrates 2a and 2a which were bonded to face each other, baked, and then rubbed (P2).

Next, as shown in FIG. 8C, the two TFT substrates 2a and 2a are opposed to the CF substrate 1 on which the temporary curing resists 24c and 24d are formed, with the side surfaces being adjacent to each other. They were arranged and bonded together (P3). Thereafter, as in Example 1, the substrates were pressed with each other under atmospheric pressure (P4).

Through this pressing step, the cell gap of the liquid crystal layer, which is the width of the gap formed between the TFT substrates 2a and 2a and the CF substrate 1, was set to 5.0 μm. With the cell gap set to 5.0 μm in this way, the above-mentioned substrates were bonded together by the viscosity of the temporarily cured resists 4c and 4d, and were temporarily fixed.

Then, each of the temporarily fixed substrates is again put into an oven and heated to be post-baked, and the temporarily-cured resist 24c bonding the respective substrates together is used.
-24d was fully cured. By this main curing, the sealing material 3 and the spacer 4 are formed, and the CF substrate 1 and the TFT
The state of being bonded to the substrates 2a was completely fixed. Therefore, in this embodiment, the step of transferring and forming the adhesive layer 4b in the first embodiment can be omitted.

Next, in order to connect the two TFT substrates 2a and 2a bonded to the CF substrate 1, FIG.
As shown in the figure, in the gap between the two TFT substrates 2a, 2a,
The ultraviolet curing adhesive 5 was filled (P5). afterwards,
As shown in FIG. 8E, liquid crystal is injected from an opening provided in the pattern of the sealing material 3 to form a liquid crystal layer 14 (P6), and the opening is sealed with a sealing material (not shown). Thus, the liquid crystal display device of the present invention was manufactured.

[Comparative Example] In the first embodiment, the resist pattern formed on the CF substrate 1 in P2 is only the pattern of the spacer 4 or the spacer 24, and is used as the sealing material 3 or the sealing material 23 as a conventional sealing material. A liquid crystal display device as a comparative example was manufactured under the same conditions and steps except that a pattern serving as the sealing material 3 was drawn on the CF substrate 1 using the coating type resin.

In the liquid crystal display device of the present invention manufactured according to each of the above embodiments, the spread of the resist serving as the sealing material from the predetermined line width when setting the cell gap was avoided. That is, in the first and second embodiments, when the substrates are pressed with each other, the sealing material 3 is hardened by the cured resist 4c.
And the adhesive layer 4d. In the third embodiment, the sealing material 23 is made of a temporary curing resist 24c. Therefore, at the time of pressing at P4, the cured resist 4c or the temporarily cured resist 24c is in a cured state, and the shape of the seal material 3 or the seal material 23 does not easily change.

Accordingly, the pressing prevents the cured resist 4c or the pre-cured resist 24c from expanding from a predetermined line width, so that the line width of the sealing material 3 is not changed at the connection portion of the TFT substrates 2a. The BM 12 could be unevenly distributed on the 6 side to the limit position. Therefore, the BM 12 which is the non-display area can have the same width as the conventionally used BM.

Further, in the liquid crystal display device of each of the above embodiments, the resists serving as the spacers 4 and 24 could be formed with high definition so as to be contained in the non-display area BM12 of the CF substrate 1. For this reason, the number of spacers 4 (Examples 1 and 2) or spacers 24 that can maintain the cell gap of the liquid crystal layer 14 as a whole sufficiently uniform.
(Example 3) could be formed without affecting the display screen.

In addition, in the liquid crystal display device of each of the above embodiments, the CF substrate 1 and the TFT substrates 2a are bonded not only with the sealing material but also with the spacer. For this reason, the structure in which the CF substrate 1 and the connection substrate 2 are bonded to each other becomes stronger than in the conventional liquid crystal display device, and the cell gap of the liquid crystal layer 14 can be maintained more uniformly as a whole. .

In the manufacturing method of the liquid crystal display device of each of the above embodiments, since both the spacer and the sealing material can be formed as one pattern in one process, the manufacturing process of the liquid crystal display device can be reduced. .

That is, the liquid crystal display device of the present invention obtained by the manufacturing method of each of the above embodiments has a uniform cell gap of the liquid crystal layer as a whole even when the screen is enlarged, as compared with the conventional liquid crystal display device. Could be maintained. Also, in the manufacturing process, the line width of the sealing material 3 does not increase,
The need to increase the area of the BM 12 is avoided, and the aperture ratio of the pixels on the display screen can be improved as compared with the conventional one.

On the other hand, the liquid crystal display device of the comparative example is
At the connection between the TFT substrates 2a, the resin serving as the sealing material 3 protruded into the image display area of the liquid crystal layer 14. For this reason, the protruding resin has an adverse effect on the display screen, and the alignment of the liquid crystal is disturbed. Therefore, the display quality of the liquid crystal display device of the comparative example was lower than that of the liquid crystal display device of each of the above examples.

As described above, in the liquid crystal display device according to the present embodiment, it was possible to avoid a decrease in the aperture ratio of the pixel.
A large screen liquid crystal display device having high display quality was obtained. In addition, the manufacturing process was not complicated, and the manufacturing cost could be reduced.

In this embodiment, a case has been described where two active matrix type small substrates using TFTs as active elements are connected side by side. However, the number of the small substrates is not particularly limited. Absent. Further, the method of manufacturing a large display screen liquid crystal display device of the present invention,
The present invention is not limited to an active matrix type liquid crystal display device using a TFT, but is an active matrix type liquid crystal display device using a MIM, a simple matrix type liquid crystal display device, a flat display type liquid crystal display device,
Further, the present invention can be applied to other flat display type display devices such as a plasma display device (PDP) and a field emission display device (FED).

[0160]

As described above, in the liquid crystal display device according to the first aspect of the present invention, a large-sized substrate having a matrix-like non-light-transmitting pattern and a plurality of small-sized substrates are connected by side surfaces thereof. In a liquid crystal display device having a single connection substrate formed so as to face and a liquid crystal layer sandwiched therebetween, a sealing material for bonding the large substrate and the connection substrate together, and a sealing material sandwiched between the large substrate and the connection substrate The spacer for maintaining the thickness of the liquid crystal layer to be maintained at a predetermined value is made of a resist having a pressure resistance.

Therefore, in the above configuration, since the sealing material and the spacer are made of resist, when setting the cell gap by pressing the large substrate and the connection substrate facing each other, the resist used as the sealing material is used. Can be in a cured state. Due to the cured resist, the resist is pressed during the above-mentioned pressing step and spreads from a predetermined line width, so that the formation region of the sealing material does not protrude into the display screen region. That is, the sealing material made of the resist has a stable shape in which the shape of the sealing material does not change more than necessary in the manufacturing process of the liquid crystal display device.

Further, since the sealing material is made of a resist, the sealing material can be formed with high definition. For this reason, in the connection portion between the small substrates,
The sealant can be formed closer to the display screen area. Therefore, it is possible to avoid widening the area of the non-light-transmitting pattern in the connection portion in order to shield the resin (resist in this case) serving as a sealing material.

Therefore, in the obtained liquid crystal display device, a decrease in the aperture ratio of the pixel is avoided, and the contrast and resolution of the display screen can be increased. As a result, there is an effect that it is possible to provide a large-screen liquid crystal display device having a high display quality in which connection portions are inconspicuous.

Since not only the sealing material but also the spacer is made of a resist, the sealing material and the spacer are formed by a developing pattern using a photomask.
It can be formed in a process and with high definition. In particular, the spacer can be formed so as to be shielded by the non-translucent pattern on the display screen and to fit within the region of the non-translucent pattern. Therefore, the spacer does not have any effect on the display screen.

As a result, a larger number of spacers than before can be formed at a stable position without affecting the display screen. Therefore, as the size of the liquid crystal display device is increased, the area of the liquid crystal layer is increased, and even if it is difficult to maintain the cell gap of the liquid crystal layer as a whole uniformly, a sufficient number of liquid crystal layers are required. Spacers can be formed. As a result, there is an effect that the uneven distribution of the liquid crystal in the downward direction due to the insufficient maintenance of the cell gap can be suppressed, and a liquid crystal display device of high quality display without display unevenness can be obtained.

A liquid crystal display device according to a second aspect of the present invention is
As described above, in addition to the configuration described in the first aspect, the resist has an adhesive property.

Therefore, in the above configuration, since the resist has adhesiveness, the connection substrate and the large-sized substrate are bonded not only with the sealing material but also with the spacer. Therefore, the bonding structure in which the substrates face each other is further stabilized, and the cell gap can be sufficiently maintained even in a large-area liquid crystal layer.

Although the resist does not protrude from a predetermined area, it is cured in a state having plasticity enough to be slightly crushed by a press. for that reason,
The resist is slightly crushed and spread by the press, and the bonding area between the resist and the opposing substrate is increased, so that the bonding strength between the substrates can be improved. As a result, there is an effect that the uneven distribution of the liquid crystal downward is further suppressed, and a liquid crystal display device of high quality display without display unevenness can be obtained.

Further, since the resist itself has an adhesive property, in order to attach the above-mentioned substrates to each other, for example, an additional layer of an adhesive is formed on the resist to complicate the manufacturing process. Is avoided. Therefore, there is an effect that the structure of the obtained liquid crystal display device can be simplified and the manufacturing cost can be reduced.

A liquid crystal display device according to a third aspect of the present invention is
As described above, in addition to the configuration described in claim 1 or 2, the spacer has a configuration further including an adhesive layer.

Therefore, in the above configuration, even when the resist itself does not have adhesiveness, adhesiveness can be imparted to the sealing material and the spacer by forming an adhesive layer. Further, even when the resist has adhesiveness, by forming the adhesive layer, the adhesiveness of the sealant and the spacer can be further ensured. Therefore, the structure in which the large-sized substrate and the connection substrate are bonded to each other can be further strengthened, and the cell gap of the liquid crystal layer can be maintained more uniformly as a whole.

A liquid crystal display device according to a fourth aspect of the present invention comprises:
As described above, in addition to the configuration described in the first, second, or third aspect, the liquid crystal layer is configured to be separated by a sealant for each of a plurality of small substrates.

Therefore, in the above configuration, the liquid crystal display device is provided with a liquid crystal display device such that the entire display screen does not have a sense of incongruity, that is, the step at the connection between the small substrates does not adversely affect the display screen. The cell gap of the layer can be controlled for each of the small substrates. In addition, since the area of the liquid crystal layer is small for each small substrate, the uniformity of the entire cell gap is more easily maintained by the spacer made of the resist. As a result, it is possible to provide a large-screen liquid crystal display device having higher display quality.

A liquid crystal display device according to a fifth aspect of the present invention is
As described above, in addition to the configuration according to any one of claims 1 to 4, the connection substrate includes a plurality of small substrates with a gap that fits within the area of the matrix-shaped non-transparent pattern. This is a configuration in which the substrates are connected to each other.

Therefore, in the above configuration, since the sealing material formed at the connection portion is made of a resist,
In the connection portion, the resist serving as the sealant is not spread and does not protrude into the display screen area, and the pattern of the sealant can be formed with a finer line width and high definition. Therefore, it is not necessary to increase the area of the non-translucent pattern.

For this reason, since the connection portion forms a gap that fits within the non-light-transmitting pattern region, the pixel pitch on the display screen is made uniform throughout the display screen without lowering the aperture ratio of the pixel. can do. As a result, it is possible to prevent the connection portion from adversely affecting the display screen, and to realize a large-screen liquid crystal display device capable of high-quality display.

A liquid crystal display device according to a sixth aspect of the present invention comprises:
As described above, in addition to the configuration according to any one of claims 1 to 5, in the gap between the plurality of small substrates in the connection substrate, the refractive index substantially equal to the substrate material of the small substrates is provided. Is filled with a resin having

Therefore, in the above configuration, the large-sized substrate and the small-sized substrate are bonded together with the adhesive at the connecting portion between the small-sized substrates, in addition to the sealing material and the spacer. For this reason, the structure in which the large-sized substrate and the connection substrate are bonded to each other can be made stronger, and in particular, the structure at the connection portion between the small-sized substrates can be made stronger. Therefore, there is an effect that the cell gap of the liquid crystal layer can be maintained more uniformly as a whole.

Further, since the adhesive has substantially the same refractive index as the substrate material of the small substrate, it is possible to prevent refraction and scattering of light between the small substrates of the connection portion. For this reason, there is also an effect that it is possible to prevent the connection section from adversely affecting the display screen.

A liquid crystal display device according to a seventh aspect of the present invention comprises:
As described above, in addition to the configuration described in any one of the first to sixth aspects, the resist serving as the spacer and the sealing material is formed on the large-sized substrate.

Therefore, in the above configuration, when a resist serving as a sealing material and a spacer is formed on a small substrate, the thickness of the resist may be different due to a step at a connection portion between the small substrates. On the other hand, by forming a resist on a large substrate, the thickness of the resist becomes constant. Therefore, an adverse effect such as a change in color tone due to a difference in the thickness of the resist can be avoided, and an effect that a high-quality display screen with less noticeable connection portions can be realized.

The liquid crystal display device according to the eighth aspect of the present invention,
As described above, in a liquid crystal display device in which a pair of substrates with electrodes are attached to face each other, and a liquid crystal layer is sandwiched between the substrates, a sealing material for attaching the pair of substrates is provided. This is a manufacturing method in which a spacer for maintaining the thickness of the liquid crystal layer sandwiched between them at a predetermined value is made of a resist having a pressure resistance.

Therefore, in the above-described manufacturing method, since the sealing material and the spacer are made of a resist, the sealing material and the spacer can be formed in one step and with high definition by a development pattern using a photomask. . Therefore, the spacers can be easily formed so as to fit within the non-display pattern region, and the number of spacers capable of sufficiently maintaining the cell gap can be formed without adversely affecting the display screen. Therefore, there is an effect that the structure of the obtained liquid crystal display device can be stabilized, and a decrease in display quality due to uneven distribution of liquid crystal or the like can be avoided.

In the method for manufacturing a liquid crystal display device according to the ninth aspect of the present invention, as described above, a sealing material and a resist serving as a spacer are cured on a large-sized substrate having a matrix-like non-translucent pattern. A step of forming a predetermined pattern in a state in which the small substrates are opposed to the large substrate on which the resist is formed, such that a plurality of small substrates are adjacent to each other on a side surface to form one connection substrate. And bonding the large substrate and the connection substrate facing each other, and setting the thickness of a space sandwiched between the large substrate and the connection substrate to a predetermined value. It is a manufacturing method.

Therefore, in the above manufacturing method, when each of the substrates is pressed for setting the cell gap, the sealing material and the spacer are formed as a hardened resist. By this curing, the shape of the resist becomes stable. Therefore, by pressing the substrates, the resist serving as the sealing material is prevented from spreading from a predetermined line width and protruding into the display screen area. Similarly, the spacer also extends from the predetermined area, and does not protrude from the non-light-transmitting pattern to the display screen area, for example. Therefore, it is not necessary to increase the area of the non-light-transmitting pattern that shields the seal material and the spacer, and to consider the protrusion of the seal material and the spacer. Therefore, there is an effect that the aperture ratio of the pixel can be improved.

[0186] The resist serving as the sealant and the spacer can be formed in one step by a development pattern using a photomask. For this reason, there is an effect that the complication of the manufacturing process can be avoided and the manufacturing process can be simplified.

Further, in the above manufacturing method, when bonding the connection substrate to the large substrate, a plurality of small substrates are bonded to the large substrate first and then connected. For this reason, when connecting small substrates first and bonding them to a large substrate, the structure of the connection substrate does not become unstable due to the small area of the connection portion between the small substrates. Therefore, there is also an effect that it is possible to avoid complication of the manufacturing process such as requiring care in handling the connection substrate.

According to a tenth aspect of the present invention, in the method of manufacturing a liquid crystal display device according to the ninth aspect, an adhesive is further applied to the surface in contact with the large-sized substrate. A transfer substrate, which is attached to the large-sized substrate so as to face the large-sized substrate, thereby transferring and forming an adhesive layer on the resist.

Therefore, in the above manufacturing method, the transfer substrate and the large-sized substrate on which the resist is formed can be formed only by transferring the adhesive layer by pressing.
There is an effect that complication of the manufacturing process is avoided.

According to the method for manufacturing a liquid crystal display device according to the eleventh aspect of the present invention, as described above, in the manufacturing method according to the ninth or tenth aspect, the opposing substrates are pressed by atmospheric pressure. Is the way.

Therefore, in the above manufacturing method, when bonding the large substrate and the small substrate, the substrates are bonded to each other with a substantially uniform cell gap including the connection surface between the small substrates. be able to. Therefore, the cell gap of the liquid crystal layer of the obtained liquid crystal display device can be made more uniform as a whole. In addition, even when the above adhesive layer is transferred, the large substrate and the transfer substrate can be pressed more uniformly as a whole. Therefore, there is an effect that the transferred adhesive layer can be made more uniform.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a liquid crystal display device according to an embodiment of the present invention.

FIG. 2 is a plan view of the liquid crystal display device of FIG.

FIG. 3 is an exploded perspective view of a main part showing a configuration of a pixel unit of the liquid crystal display device of FIG.

FIG. 4 is a plan view showing a configuration of a pixel portion and a non-display portion in the liquid crystal display device of FIG.

5 is a diagram showing a flow of an entire manufacturing process in the method of manufacturing the liquid crystal display device of FIG.

FIGS. 6A to 6D are process diagrams illustrating a method for manufacturing the liquid crystal display device of FIG.

7 (a) to 7 (d) are process diagrams showing a method for manufacturing the liquid crystal display device of FIG. 1, which is a continuation of FIG.

FIGS. 8A to 8E are process diagrams showing another method for manufacturing the liquid crystal display device of FIG.

FIG. 9 is a cross-sectional view illustrating a configuration of a modified example of the liquid crystal display device of the present invention.

10A is a perspective view of a conventional liquid crystal display device, and FIG. 10B is a cross-sectional view of the liquid crystal display device of FIG.

[Explanation of symbols]

 Reference Signs List 1 CF substrate 2 Connection substrate 2a TFT substrate 3 Sealing material 4 Spacer 4a Resist layer 4b Adhesive layer 4c Hardened resist 4d Hardened resist 12 Black matrix (non-light-transmitting pattern) 14 Liquid crystal layer 23 Sealing material 24 Spacer 24a Resist layer 24c Temporary Cured resist 24d Temporary cured resist

Claims (11)

[Claims] 1. A large-sized substrate having a matrix-like non-light-transmitting pattern is opposed to a single connection substrate formed by connecting a plurality of small-sized substrates on side surfaces thereof. In the liquid crystal display device sandwiched, a sealing material for bonding the large substrate and the connection substrate, and a spacer for maintaining the thickness of the liquid crystal layer sandwiched between the large substrate and the connection substrate at a predetermined value, A liquid crystal display device comprising a resist having a pressure resistance. 2. The liquid crystal display device according to claim 1, wherein said resist has an adhesive property. 3. The liquid crystal display device according to claim 1, wherein said spacer further comprises an adhesive layer. 4. The liquid crystal display device according to claim 1, wherein said liquid crystal layer is separated by a sealing material for each of a plurality of small substrates. 5. The connection substrate according to claim 1, wherein the plurality of small substrates are connected to each other at a gap which is accommodated in a matrix-shaped non-translucent pattern region provided on the large substrate facing the connection substrate. The liquid crystal display device according to any one of claims 1 to 4, wherein: 6. The connection substrate according to claim 1, wherein a gap between the plurality of small substrates in the connection substrate is filled with a resin having a refractive index substantially the same as the substrate material of the small substrates. The liquid crystal display device according to claim 1. 7. The liquid crystal display device according to claim 1, wherein the resist serving as the spacer and the sealing material is formed on the large-sized substrate. 8. A liquid crystal display device in which a pair of substrates with electrodes are attached to each other so as to face each other, and a liquid crystal layer is sandwiched between the substrates. A spacer for maintaining the thickness of the liquid crystal layer sandwiched between the spacers at a predetermined value, the spacer being made of a resist having a pressure resistance. 9. A step of forming a resist as a sealing material and a spacer as a predetermined pattern on a large-sized substrate having a matrix-like non-light-transmitting pattern, and forming the resist into a predetermined pattern. A step of laminating the small substrates facing each other so that a plurality of small substrates are adjacent to each other on a side surface thereof to form a single connection substrate; and Setting the thickness of the space sandwiched between the large-sized substrate and the connection substrate to a predetermined value by pressing. 10. A transfer substrate having an adhesive applied to the surface in contact with the large-sized substrate is bonded so as to face the large-sized substrate, thereby forming an adhesive layer on the resist. 10. The method for manufacturing a liquid crystal display device according to claim 9, further comprising a step of performing transfer formation. 11. The method for manufacturing a liquid crystal display device according to claim 9, wherein said opposed substrates are pressed with each other under atmospheric pressure.