JPH1054994A - Production of liquid crystal panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To widen the process margin in an adhering stage and to stably obtain a liquid crystal panel having a uniform intersubstrate spacing by bulging the part near the central part of substrates facing each other to adhere the peripheral part thereof, deformation the bulge near the central part to a recess injecting liquid crystals between the substrates from the recessed state. SOLUTION: The first glass substrate 1 having thin-film transistors, etc., is disposed to face the second glass substrate 3 having common electrodes, etc., and the peripheral parts of these two substrates 1, 3 are adhered by an adhesive resin 2. At this time, the liquid crystal panel is so formed that the panel gap in the central part bulges. This panel is put into a vacuum furnace and the atmospheres in and out of the panel are made vacuum. While this state is maintained, the injection port 4 of the panel is dipped in a liquid crystal pool having the liquid crystals and, thereafter, the atmospheres in and out of the liquid crystal panel are restored to the atm. pressure. At this time, the central part of the panel is recessed by the atm. pressure difference between the inside and the outside of the panel. The injection port 4 is closed by a sealing material at the point of the time the liquid crystals are packed into the panel and the panel gap is made plane and uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a liquid crystal panel.

[0002]

2. Description of the Related Art In a liquid crystal panel, the distance between two opposing substrates (panel gap) is one of the factors that determine very important characteristics such as the response speed, light transmittance, and image quality of the liquid crystal panel. .

First, a conventional method for manufacturing a liquid crystal panel will be described. FIG. 7 shows the above 2 in the conventional liquid crystal assembling process.
It is sectional drawing of the process of adhering two glass substrates. As shown in FIG. 7, an adhesive resin 2 mixed with fibers is formed as a spacer for setting a substrate interval around the first glass substrate 1, and the second glass substrate 3 is attached to the adhesive resin 2. Glue. Here, when the two glass substrates 1 and 3 are bonded, the two glass substrates 1 and 3 are
At 0 and 11 respectively, they are pressed and bonded.

That is, the distance between the two glass substrates 1 and 3 is controlled by curing the adhesive resin 2 while pressing the two glass substrates 1 and 3 with the pressure stages 10 and 11.

[0005]

However, the conventional method has the following problems.

[0006] The flatness of the pressing stage in the bonding step and the distortion of the pressing stage during pressing greatly affect the uniformity of the spacing between the substrates after bonding. That is, in the bonding step under the condition in which the planar accuracy of the pressing stage and the planar accuracy at the time of pressing are taken into consideration, the process margin becomes extremely narrow.
In other words, there is a problem that the likelihood of setting the conditions in each process is narrowed. Further, in order to ensure the uniformity of the interval between the two glass substrates, a fiber as a spacer is mixed into the display portion of the panel, so that there is a problem that the pixels of the panel display portion are damaged when pressurized. .

An object of the present invention is to provide a manufacturing method capable of expanding a process margin in a bonding step and stably obtaining a liquid crystal panel having a uniform distance between two substrates.

[0008]

In order to solve this problem, the invention according to claim 1 of the present invention is directed to a peripheral portion of two substrates opposed to each other in a form in which the vicinity of the central portion is expanded. Bonding together, deforming a bulge near the center of the substrate into a dent, injecting a liquid crystal between the substrates from a state in which the substrate is depressed, and using a liquid crystal injected between the substrates. And closing the injection port when the distance between the substrates becomes constant. With this configuration, the process margin can be expanded. Further, according to this configuration, since there is no need to interpose a spacer in the substrate display section, there is no risk of damage to the panel pixel section by the spacer.

The invention described in claim 2 is the first invention.
In the method for manufacturing a liquid crystal display panel described above, the peripheral portions of the substrates are adhered to each other while the respective substrates are vertically adsorbed by vacuum when the vicinity of the central portion of the two substrates is expanded. With this configuration, the area near the center of the panel can be effectively expanded.

According to a third aspect of the present invention, in the method for manufacturing a liquid crystal panel according to the first or second aspect, after the peripheral portions of the two substrates are bonded to each other, the swelling between the substrates is determined by using a pressure difference. It is concave. With this configuration, the inside of the liquid crystal panel can be evacuated.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 are views showing a bonding step in the method of manufacturing a liquid crystal panel according to the present invention. FIG. 1A shows a substrate gap in a bonding process (hereinafter, referred to as a panel gap).
FIG. 1B is a plan view of the same. A first glass substrate 1 provided with a thin film transistor, a NIM and the like is opposed to a second glass substrate 3 provided with a common electrode and the like. Adhere with 2. The adhesive resin 2 is formed on the peripheral portions of the glass substrates 1 and 3, but the liquid crystal injection port 4 is partially formed.
have. Here, the first and second glass substrates 1 and 3 may be thin film transistor type liquid crystal display devices or simple matrix type liquid crystal display devices.
The first and second glass substrates 1 and 3 are made of quartz glass, soda glass, or the like.

The liquid crystal panel is formed such that the panel gap at the center is swelled. That is, as shown in FIG. 2, the central part of the first glass substrate 1 is adsorbed on the suction stage 8 and the central part of the second glass substrate 3 is adsorbed on the adsorption stage 9 up and down. Is sandwiched. Then, the first and second glass substrates 1 and 3 are pressed by the suction stages 8 and 9 with these substrates being distorted. After that, when the pressure is released and the adhesive resin 2 is cured, the gap at the center of the panel is expanded. At this time, if the first and second glass substrates 1 and 3 are adsorbed on the adsorption stages 8 and 9 in a vacuum, the adsorption can be performed effectively.

FIG. 3 is a view showing a panel gap state of the liquid crystal panel immediately after the liquid crystal is injected between the first and second glass substrates after the above-mentioned bonding step. FIG. 3A is a sectional view of the liquid crystal panel, and FIG. 3B is a plan view of the same.

This liquid crystal panel is formed so that the panel gap at the center is depressed. A specific method is as follows. The panel shown in FIG. 1 is placed in a vacuum furnace (not shown).
While the atmosphere inside and outside the panel was evacuated and maintained in that state, as shown in FIG.
Then, the atmosphere outside the liquid crystal panel is returned to the atmospheric pressure. At this time, the central part of the panel is depressed due to the pressure difference between the inside and the outside of the panel.

FIG. 4 is a view showing a gap state of the liquid crystal panel in a state where liquid crystal is injected between two glass substrates and left as it is from the liquid crystal injection step (immediately before injection) shown in FIG. FIG. 4A is a sectional view thereof, and FIG. 4B is a plan view thereof.

When left in this state, the liquid crystal panel
The gap at the center of the panel gradually expands to restore the state at the time of bonding.

When the liquid crystal is filled in the panel and the panel gap becomes uniform on the plane, the injection port 4 is closed with a sealing material 7 as shown in FIG. Here, a method of confirming that the panel gap becomes uniform is that a panel with the liquid crystal injected is irradiated with monochromatic light, and a uniform panel gap is obtained when interference fringes disappear from the liquid crystal.
In this way, uniformity of the panel gap is ensured.

FIG. 6 shows the transition of the panel center gap value in each step. The panel center gap value is as shown by the solid line in FIG. The gap value at the center of the panel during the bonding step in which the first and second glass substrates 1 and 3 are swollen is α. The gap value immediately before the liquid crystal injection when the first and second glass substrates 1 and 3 are depressed is γ. Then, the liquid crystal is injected between the first and second glass substrates 1 and 3, and the gap value of the central portion of the panel in a state where the liquid crystal is left is increased with time. The injection is stopped at the point of time when the intervals between the panels become uniform, and the inlet is closed. Therefore, if the injection of the liquid crystal is not stopped after leaving the β value, and the liquid crystal is left to stand, the center gap value of the panel follows the dashed line, and the center gap value of the panel becomes large.

An embodiment of the present invention will be described below. First, the first glass substrate 1 has a thickness of 1.1 mm,
A glass substrate 3 having a thickness of 0.7 mm is used. The substrate size is 1.3 type.

In the bonding step, the central part of the first glass substrate 1 is vacuum-suctioned vertically by the suction stage 8 and the central part of the second glass substrate 3 is vertically sucked by the suction stage 9 to mix fibers (3 μm). The pressure is set to 3 kg / panel so as to sandwich the epoxy-based photocurable resin 2, and after confirming that the peripheral gap of the panel becomes the diameter of the fiber (3 μm), the pressure is set to 0 kg / panel and the first glass substrate is pressed. UV light with a wavelength of 350 nm from the 1 side is 100
The epoxy-based photocurable resin 2 is cured by applying 00 mJ.

In the liquid crystal injection step, the pressure inside the panel is set to 0.0
After reducing the pressure to 03 torr or less, the panel is immersed in a liquid crystal having a viscosity of about 25 cp, and the pressure outside the panel is returned to the atmospheric pressure and left.

In the sealing step, an epoxy-based photocurable resin is applied to the panel left for 4 hours after the injection of the liquid crystal, and
After standing for 10 minutes, 25,000 mJ of UV light having a wavelength of 350 nm is applied at an integrated irradiation dose.

As a result, it is possible to stably obtain a liquid crystal panel having good panel gap uniformity.

As described above, one embodiment of the present invention has been described, but it can be adjusted appropriately within the following range.

First, the thickness of the first glass substrate 1 is 0.5
1.3 mm, the thickness of the second glass substrate 3 is 0.5 to
1.3 mm can be used.

Next, in the bonding step, the first glass substrate 1
The central part of the second glass substrate 3 is vacuum-absorbed vertically by the suction stage 9 and the center part of the second glass substrate 3 is vertically sucked by the suction stage 9, and the epoxy-based photocurable resin 2 mixed with fibers having a diameter of 2.5 to 5 μm And pressurize it at 2-10 kg / panel so that the peripheral gap of the panel becomes an arbitrary diameter depending on the diameter of the fiber.
/ Panel, wavelength 350n from the first glass substrate 1 side
m-UV light is applied to the epoxy-based photo-curable resin 2 at an integrated irradiation dose of 1000 to 20,000 mJ.

Further, in the liquid crystal injection step, after the pressure in the panel is set to 0.001 to 0.01 torr, the viscosity is set to 20.
It is attached to a liquid crystal of about 30 cp, and the outside pressure of the panel is returned to the atmospheric pressure and left.

Finally, in the sealing step, after the injection of the liquid crystal,
An epoxy-based photocurable resin is applied to the injection port 4 on the panel left for 10 to 10 hours, and left for 0 to 20 minutes.
0-2nm UV light at 1000-25000m in integrated irradiation amount
J

[0030]

As described above, according to the present invention,
The flatness of the pressing stage, the flatness at the time of pressing, the process margin due to the warpage of the substrate, and the like can be widened, and the likelihood of setting the conditions in the process can be widened.
Further, since it is not necessary to interpose a spacer in the display portion of the substrate, it is possible to prevent the panel from being damaged during pressurization.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view of a liquid crystal panel in a manufacturing method of the present invention. FIG.

FIG. 2 is a sectional view of a liquid crystal panel in the manufacturing method of the present invention.

FIG. 3A is a sectional view of a liquid crystal panel in the manufacturing method of the present invention.

FIG. 4A is a sectional view of a liquid crystal panel in the manufacturing method of the present invention.

5A is a cross-sectional view of a liquid crystal panel in the manufacturing method of the present invention, and FIG.

FIG. 6 is a transition diagram of a gap value at the center of the panel in each process.

FIG. 7 is a process chart of a conventional liquid crystal panel manufacturing method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st glass substrate 2 Adhesive resin 3 2nd glass substrate 4 Injection port 5 Liquid crystal 7 Sealing material

Claims (3)

[Claims] 1. A step of bonding peripheral portions of two substrates facing each other in a form in which the central portions of the two substrates facing each other are swelled.
A step of deforming a bulge near the center of the substrate into a depression, a step of injecting liquid crystal between the substrates from a state where the substrate is depressed, and the distance between the substrates being fixed by the liquid crystal injected between the substrates. And c. Closing the injection port when the liquid crystal panel becomes a liquid crystal panel. 2. The method for manufacturing a liquid crystal panel according to claim 1, wherein, when the vicinity of the center of the two substrates is expanded, the peripheral portions of the substrates are sucked up and down by vacuum. A method for manufacturing a liquid crystal panel, comprising bonding. 3. The method for manufacturing a liquid crystal panel according to claim 1, wherein the peripheral portions of the two substrates are bonded to each other, and then the bulge between the substrates is depressed by using a pressure difference. Liquid crystal panel manufacturing method.