JP2001228477A - Manufacturing method of liquid crystal display, and back light - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a bright big screen image by a large-sized liquid crystal display device good in angle-of-view characteristics, inexpensive in manufacturing cost, small in power consumption and light in weight, with little display unevennesss. SOLUTION: In a side edge lamp system back light of the liquid crystal display device, a transparent light transmission plate is the plane in a surface of a liquid crystal panel side, has a groove structure of a chevron shape where the thickness of the light transmission plate of a central part of a picture is thin in the surface of the opposite side at the side of the liquid crystal panel, and the blast processing to make the irregular reflection of the light is performed in either the planar surface or the surface of the chevron shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device having a large screen and high brightness.

[0002]

2. Description of the Related Art Conventionally, a light guide plate of a backlight for a large liquid crystal panel has been formed by forming light scattering dots on a parallel plate of acrylic by screen printing. Since the screen printing method was used, the printing surface of the light guide plate had to be flat.
Because the scattering dots are located locally, a diffuser sheet had to be placed under the prism lens film to obtain illumination of uniform brightness.

In a conventional manufacturing process of a thin film transistor,
When forming video signal wiring (source electrode) and drain electrode, after processing the pattern by wet etching,
He immediately stripped the photoresist. Thereafter, the n ⁺ amorphous layer on the back channel side was removed by dry etching. Dry etching used at this time
As the gas, a gas containing sulfur hexafluoride (SF ₆ ) as a main component is used, and the etching selectivity between the i amorphous layer and the n ⁺ amorphous layer is almost close to 1. In a dry etcher used in a manufacturing process of a thin film transistor, discharge electrodes are horizontally arranged.

When a color filter substrate and an active matrix substrate are bonded in a liquid crystal cell forming process,
The stage of the hot plate directly contacts the glass substrate,
Conventionally, a method of applying heat and pressure has been used.

[0005]

As shown in FIG. 1, a conventional backlight uses a parallel-plate type light guide plate, and the larger the liquid crystal panel, the greater the weight of the acrylic light guide plate. Occurs. In order to obtain a TV image on a liquid crystal panel, it is necessary to further improve the brightness of the backlight. To achieve this, the light guide plate must be further thickened and the number of lamps must be increased. Thickening the light guide plate further increases the weight. Increasing the number of lamps increases power consumption, the number of inverters, and the cost of the backlight sharply increases. The advantage of the liquid crystal panel is reduced. Increasing the discharge current of the lamp causes a problem in that the acrylic light guide plate, which is weak to heat, is deformed due to heat generation.

In a conventional manufacturing process of a thin film transistor,
When removing the n ⁺ amorphous layer on the back channel side by dry etching, dry etching was performed after removing the photoresist. When dry etching is performed only with a fluorine-based etching gas, there is no problem in this step, but the selectivity between n ⁺ amorphous silicon and non-doped amorphous silicon (i-layer) cannot be improved, and a large display element is manufactured. There was almost no process margin. If a chlorine-based or bromine-based dry etching gas is used with the photoresist removed, there is a problem that these gases are adsorbed on the metal wiring and corrode the metal wiring. Further, when a chlorine-based or bromine-based gas is used, a chlorine compound or a bromine compound is apt to remain in the back channel region, thereby deteriorating the characteristics of the thin film transistor.

In the conventional process of forming a liquid crystal cell, when bonding a color filter substrate and an active matrix substrate, an epoxy-based adhesive is used as a sealing material, so that a heating and pressing process must be performed. When heating, if the temperature difference between the upper substrate and the lower substrate is large, the two substrates bend as in the bimetal phenomenon. When the glass substrate is deformed, the alignment is shifted and the yield is reduced. Poor parallelism of the upper and lower stages resulted in poor gaps.

[0008] The present invention provides means for solving these problems. It is an object of the present invention to manufacture a large-sized liquid crystal display device at low cost, reduce the weight of the whole device,
An object is to improve luminance without increasing power consumption.

[0009]

Means for Solving the Problems In order to solve the above problems and achieve the above object, the present invention uses the following means.

[Means 1] A light guide plate of a side edge lamp type backlight of a liquid crystal display device has an inverted V-shaped groove structure. The surface on the liquid crystal panel side is a plane, and the surface on the opposite side is the same as the drawing. The structure was such that the thickness became thinner toward the center. The surface on the reverse V-groove side was blasted so that light could be scattered.

[Means 2] The light guide plate of the side edge lamp type backlight of the liquid crystal display device has an inverted V-shaped groove structure, the surface on the liquid crystal panel side is flat, and the surface on the opposite side is the screen surface. The structure was such that the thickness became thinner toward the center. The plane on the liquid crystal panel side was blasted so that light could be scattered.

[Means 3] In the light guide plate described in the means 1 or 2, the density of the unevenness of the surface due to the sandblasting process is small near the lamp side and increases as approaching the center of the light guide plate. The maximum was set at the center.

[Means 4] In a side edge lamp type backlight light guide plate, a heat-resistant plastic is inserted between the lamp and the light guide plate on the end face side where the lamp is installed.

[Means 5] The thickness of the thinnest portion at the center of the light guide plate described in Means 1 and 2 is set to be half or less of the thickest portion near the lamp light source.

[Means 6] Side walls are formed on two side edges of the light guide plate described in Means 1 and 2, respectively, on which no light is installed.

[Means 7] Inverted stagger type back channel
Regarding the manufacturing process of the etching type thin film transistor,
After the video signal wiring and the drain electrode were formed by etching, the n ⁺ amorphous silicon layer doped with phosphorus was dry-etched without removing the photoresist and leaving the photoresist attached.

[Means 8] Inverted stagger type back channel
In the manufacturing process of the etching type thin film transistor,
When dry-etching an n ⁺ amorphous silicon layer doped with phosphorus, chlorotrifluoromethane [CCl
F _3] or trifluoroacetic dibromomethane _[CB r _{F 3]} or a three trifluoroiodomethane [CIF _3] was used as the etching gas.

[Means 9] An oxygen gas and a rare gas such as a helium gas or an argon gas are mixed with the halogenated methane trifluoride gas used in the means 8, and the n ⁺ amorphous silicon layer doped with phosphorus is dry-etched.

[Means 10] In the manufacturing process of the reverse stagger type back channel etching type thin film transistor,
After dry etching the n ⁺ amorphous silicon layer doped with phosphorus without removing the photoresist, a mixed gas of diborane [B ₂ H ₆ ] gas and hydrogen gas [H ₂ ] is used in another chamber without breaking the vacuum. Then, the plasma discharge treatment was performed on the interface on the back channel side.

[Means 11] In the manufacturing process of the reverse stagger type back channel etching type thin film transistor,
After dry-etching the n ⁺ amorphous silicon layer doped with phosphorus, the thin film transistor substrate was once taken out into the atmosphere, and then the photoresist was plasma-ashed and then peeled.

[Means 12] The inner wall of the chamber for dry etching the n ⁺ amorphous silicon layer, the discharge electrode,
The material of the inner surface such as the stage on which the glass substrate is mounted is made of a black material such as amorphous carbon, silicon carbide, or a composite material of carbon and aluminum.

[Means 13] With respect to a dry etcher for processing a thin film silicon semiconductor layer, high-frequency discharge electrodes are vertically arranged in a range of 80 to 90 degrees with respect to the horizontal, and the glass substrate is transported horizontally from a loader. After that, it is placed horizontally on the susceptor in the dry etching chamber. Thereafter, the lower portion of the susceptor was allowed to rotate until the susceptor became parallel to the discharge electrode.

[Means 14] Regarding the vertical dry etcher described in Means 13, the discharge region and the rotation region of the susceptor are completely separated during the discharge so that the dry etching reaction gas does not flow into the susceptor rotation region. did.
The exhaust of the dry etching reaction gas was exhausted from an exhaust port provided around the discharge area.

[Means 15] In a manufacturing process of a liquid crystal panel, when a pair of glass substrates are bonded together by using a sealing material, a horizontally arranged porous ceramic stage or
Using a porous metal stage, hot air was blown from above and below the two bonded substrates, and the two substrates were heated and pressurized and pressure-bonded while the two substrates were floating in the air. . After the epoxy-based sealing material gels and is completely pressed down to the gap set by the liquid crystal cell spacers, cool air is blown out from above and below the two bonded substrates and the two substrates are suspended in the air In this state, cooling was enabled.

[0025]

According to the means 1, 2, 3, and 5, in the case of the scattering dots using the conventional printing method, the diffusion sheet, which is absolutely necessary to obtain uniform luminance, is no longer necessary. By adjusting the density of the blasting treatment and the strength of the unevenness on the surface, it became easier to obtain a uniform luminance. Since the volume of the inverted V-groove type light guide plate is much smaller than that of the conventional parallel plate type light guide plate, a significant weight reduction can be realized. By making the central part of the light guide plate thinner, it becomes easier to emit light to the liquid crystal panel side, and even if the number of times light is scattered inside the light guide plate is small, light can be extracted to the liquid crystal panel side, improving brightness. it can.

By using the means 4, even if the discharge current of the lamp is increased, thermal deformation of the light guide plate does not occur. Further, the distance between the lamp and the end face of the light guide plate can be made zero, and the lamp and the light guide plate can be brought into contact. Thereby, the solid angle at which light generated from the lamp enters the light guide plate can be increased. The efficiency of capturing light into the light guide plate is greatly improved.

By using the means 6, even if the thickness of the center of the light guide plate is reduced, mechanical strength can be maintained and deformation of the light guide plate can be prevented.

By means 7, 8, and 9, the video signal wiring can be protected from the corrosive gas generated by the plasma reaction, and only the phosphorus-doped n ⁺ amorphous silicon layer can be selectively dry-etched. Become like Even if the film forming uniformity of plasma CVD is poor, only the n ⁺ amorphous silicon layer can be selectively dry-etched, so that non-uniformity of the characteristics of the thin film transistor element hardly occurs. By mixing a rare gas, the selectivity can be improved and the uniformity of plasma can be increased, so that the glass substrate can be made larger.

Since the threshold voltage on the back channel side of the thin film transistor can be shifted to the plus side by the means 10 and 11, the leakage current near the sub-threshold of the thin film transistor can be greatly reduced, and the leakage current can be reduced. Uniformity can be greatly improved.

According to the means 12, the light generated by the plasma discharge is absorbed by the inner wall of the chamber during the plasma dry etching, so that the etching rate of the non-doped amorphous silicon layer can be reduced. n
⁺ The dry etching selectivity of the amorphous silicon layer can be further improved.

The means 13 and 14 prevent particles generated in the dry etching process and flakes generated by peeling off the reactant deposited on the discharge electrode from falling onto the glass substrate. This greatly reduces the number of dusts adhering to the glass substrate.

Since the heating can be performed under pressure by the means 15 without the glass substrate and the heating stage coming into contact with each other, it is possible to prevent a sudden rise in the temperature of only one of the upper and lower glass substrates. Since the stage and the glass substrate are not in contact with each other, there is no local increase in pressure due to foreign matter, and the foreign matter does not stick to the glass substrate. Even if the accuracy of the parallelism of the upper and lower stages is poor, non-uniform pressurization will not occur, so that a liquid crystal cell gap defect does not occur.

[0033]

FIG. 2 is a sectional view of a backlight according to a first embodiment of the present invention. One prism lens film is arranged under the polarization separation film, and the surface of the light guide plate that is in contact with the prism lens film is flat, the thickness at the center is the thinnest, and the two end portions on the side where the lamp is arranged are located. The thickness is the thickest. The inverted V-shaped surface of the light guide plate has irregularities transferred from a blasted mold. The density of the irregularities is greatest at the thinnest central part, and at the two ends on the lamp side. The thickest part has the lowest density. Below the surface on the side of the inverted V shape, a pure white reflection film or a mirror-like reflection film on which silver is deposited is disposed. Although not shown in FIG. 2, the reflection film is fixed by a reflection film fixing plate having a shape as shown in FIGS. 7 and 10 under the reflection film so as not to sag. In FIG. 2, two lamps are arranged on one side and a total of four lamps are arranged on both sides. However, when the thickness of the light guide plate is small, one lamp is arranged on one side and a total of two lamps are arranged on both sides.

Embodiment 2 FIG. 3 is a sectional view of a backlight according to a second embodiment of the present invention. The difference from FIG. 2 is that the flat side of the light guide plate in contact with the prism lens film is blasted. The density of the unevenness in the blasting process is the same as in FIG. 2 in that the central portion having the smallest thickness has the largest density, and the two end portions on the lamp side have the smallest density in the portion having the smallest thickness. . The luminance distribution of the backlight can be controlled by controlling the density of the unevenness and the height (intensity) of the unevenness in the blasting process.

Embodiment 3 FIG. 4 is a sectional view of a backlight according to a third embodiment of the present invention. 2 in that a diffusion plate film is used instead of the prism lens film. Although the brightness in the front direction is lower than that of the prism lens film, the brightness is uniform at a wide viewing angle, so that it is used for a liquid crystal panel requiring a wide viewing angle. Diffusion plate films are used as ultra-large, low-cost backlights because they are cheaper than prism lens films.

Embodiment 4 FIG. 5 is a sectional view of a backlight according to a fourth embodiment of the present invention. The difference from FIG. 2 is that the shape of the light guide plate is not an inverted V shape but an inverted U shape. The thinnest portion of the light guide plate is not pointed but is curved. When the thickness of the thinnest central part of the light guide plate becomes 1 mm or less,
In the case of the inverted V-shaped groove, luminance unevenness of a pointed portion is likely to occur and is easily seen by the eyes. However, by forming the groove portion into a round and gently curved shape, luminance unevenness does not occur. As shown in FIG. 3, the blast processing may be performed on the plane side.

Embodiment 5 FIG. 6 is a side view of a light guide plate according to a fifth embodiment of the present invention. When the thickness of the central portion of the light guide plate is small, the light guide plate shown in FIG.
There are two side walls ▼. FIG. 9 is also one of the embodiments of the present invention, but when the thickness of the central portion of the light guide plate is large, a side wall for reinforcing the strength is not necessary.

Embodiment 6 FIGS. 7 and 8 show a sixth embodiment of the present invention.
It is a side view from two directions of the white reflective film fixing plate which is an Example of. This is a white reflective film fixing plate when the light guide plate has side walls, and is made of white plastic. FIGS. 10 and 11 are also side views from two directions of the white reflective film fixing plate according to the embodiment of the present invention. It is a white reflective film fixing plate when the light guide plate has no side wall. These fixing plates allow the white reflective film to contact the light guide plate without sagging. In the case of an inverted U-shaped light guide plate as shown in FIG. 5, the sharpness of the central portion of the white reflection film fixing plate is rounded so that the white reflection film contacts the light guide plate over the entire surface.

Seventh Embodiment FIG. 21 is a sectional view of a backlight according to a seventh embodiment of the present invention. The difference from FIG. 4 is that heat-resistant transparent plastic is used for the light guide plate near the lamp, the discharge current density of the lamp can be made larger than that in FIG. 4, and the distance between the lamp and the light guide plate is conventionally different. Is separated using a silicon rubber ring of 0.2 to 0.3 mm, but in the present invention, the lamp and the light guide plate can be brought into direct contact. As shown in FIG. 21, it is also possible to cut out the heat-resistant transparent plastic and fit the lamp inside the transparent plastic. With this structure, the amount of light incident on the light guide plate from the lamp increases, so that the luminance can be improved.

[Embodiment 8] FIG. 12 is a sectional view of an inverted stagger type thin film semiconductor transistor. It is important that the n ⁺ amorphous silicon layer doped with phosphorus is removed by dry etching without removing the photoresist after forming the source and drain electrodes by etching. When the n ⁺ amorphous silicon layer is dry-etched after removing the photoresist, if a chlorine-based or bromine-based gas is contained in the etching gas used, the source / drain electrodes are corroded or the gas adsorbed on the surface of the electrode becomes a passivation film. It may be mixed into the liquid crystal and cause deterioration of the alignment film of the liquid crystal. These problems do not occur at all when dry etching is performed by attaching a photoresist. The non-doped amorphous silicon layer is usually deposited to a thickness of about 2000 Å, and the n ⁺ amorphous silicon layer is deposited to a thickness of about 300 Å. As the dry etching gas for the n ⁺ amorphous silicon layer, sulfur hexafluoride [SF ₆ ] gas, hydrogen chloride [HCl] gas and rare gas [He or Ar or N 2]
e), the dry etching selectivity between the n ⁺ amorphous silicon layer and the non-doped amorphous silicon layer was almost close to 1. For this reason, if both the deposition uniformity and the dry etching uniformity of the n ⁺ amorphous silicon layer and the non-doped amorphous silicon layer are not good, good transistor characteristics cannot be obtained, resulting in a decrease in yield. In particular, when a meter-sized glass substrate is used, it has been a very serious problem. In the present invention, methane iodide trifluoride [CIF ₃ ] or methane trifluoride bromo [C
By using [BrF ₃ ] or chlorotrifluoromethane [ClF ₃ ], the selectivity between the n ⁺ amorphous silicon layer and the non-doped amorphous silicon layer can be increased to 5 or more. By mixing oxygen gas [O ₂ ] and argon gas [Ar] with the halogenated trifluoromethane gas, the selectivity can be further improved. When the amount of oxygen gas is large, the selectivity increases, but the etching rate decreases. Helium gas [He] or neon gas [Ne] may be used instead of the argon gas. By mixing these rare gases, the uniformity of the plasma discharge is improved, and the reaction can be promoted.

[Embodiment 9] FIGS. 14 and 15 are schematic diagrams showing a dry etching apparatus used in the manufacturing method of the present invention and an apparatus for plasma doping a back channel with boron. After removing the n ⁺ amorphous silicon layer of the thin film transistor of FIG. 12 by dry etching, removing the photoresist by oxygen plasma ashing, and depositing a passivation film using a plasma CVD method, non-doped amorphous silicon is deposited during the ashing process. The surface of the silicon layer is plasma-oxidized to form a silicon oxide film. Phosphorus and halogen-based ions adhering to the surface of the substrate are mixed into the silicon oxide film, and tend to have transistor characteristics as shown in (26) in FIG. The leakage current near the sub-threshold is increasing, which is a characteristic not suitable for an active matrix liquid crystal panel.
In order to improve this characteristic, after the n ⁺ amorphous silicon layer is dry-etched as shown in FIGS. 14 and 15, the substrate is transferred to another chamber without breaking the vacuum, and the surface of the exposed non-doped amorphous silicon layer is removed. Next, a boron plasma doping process is performed. After the boron plasma doping treatment, oxygen plasma ashing is performed, and then the photoresist is removed. Next, a passivation film is deposited using a plasma CVD method.
The transistor characteristics obtained by performing boron plasma doping on the back channel side are the characteristics shown in (25) of FIG.

Embodiment 10 FIGS. 16 and 17 are a plan view and a sectional view of a vertical dry etcher according to the present invention. In the process of manufacturing a thin film transistor, when a gate electrode, an island of a thin film semiconductor layer, and an image signal wiring are formed by dry etching, most of the metal or semiconductor film deposited on a glass substrate must be removed by dry etching. No.
For this reason, particularly in the above process, the plasma reactant tends to adhere to the discharge electrode of the dry etching apparatus. In a conventional dry etching apparatus in which discharge electrodes are arranged horizontally, plasma reactants adhering to the discharge electrodes are peeled off and fall on the glass substrate, causing pattern defects. In order to improve the yield, the inside of the chamber had to be frequently cleaned. In the present invention, FIG.
As you can see, because the discharge electrodes are arranged vertically,
Even if the plasma reactant was peeled off and dropped, it did not adhere to the glass substrate. Although a structure similar to sputtering is adopted, in a dry etching apparatus, there is a very large difference between the gas pressure in the dry etching reaction region and the gas pressure in the region where the susceptor rotates, and furthermore, a large amount of corrosion is present in the exhaust gas. Since a reactive gas is contained, more care must be taken in exhausting the gas than in a sputtering apparatus. The vertical dry etcher of the present invention employs a structure in which the exhaust system in the dry etching reaction region and the exhaust system in the region where the susceptor rotates are completely separated. A structure is employed in which the reaction gas in the dry etching reaction region is completely sealed using an O-ring so as not to flow into the rotation region of the susceptor.

[Embodiment 11] FIGS. 14, 15, 16,
Regarding the dry etching apparatus shown in FIG. 17, the color of the inner wall, the discharge electrode, and the susceptor in the chamber for dry etching the n ⁺ amorphous silicon in the channel portion of the inverted staggered thin film transistor was changed to black or brown.
Examples of the material include amorphous carbon, silicon carbide, a composite material of carbon and aluminum, and chromite treatment of aluminum. The methane iodide trifluoride and the methane bromotrifluoride described in Example 8 are etching gases for the silicon oxide film. Since n ⁺ amorphous silicon is more easily oxidized than non-doped amorphous silicon, it is oxidized to silicon oxide when exposed to oxygen plasma. Non-doped amorphous silicon is hardly oxidized even when exposed to oxygen,
When light is irradiated to generate holes and electrons in the amorphous silicon, oxidation proceeds rapidly. In order to improve the dry etching selectivity between n ⁺ amorphous silicon and non-doped amorphous silicon, the amount of light emitted from plasma discharge may be reduced. The generated light is preferably absorbed by the inner wall of the chamber and not absorbed by the non-doped amorphous silicon layer. Unifying the inside of the dry etching chamber with a black material is particularly important for realizing a liquid crystal panel of a metric size with an inverted staggered back channel etching type thin film silicon transistor.

Embodiment 12 FIGS. 18, 19 and 20
FIG. 1 is a cross-sectional view of an apparatus for bonding two glass substrates by applying heat, pressure, and bonding, and a plan view of a stage. A porous ceramic or porous metal is placed on the upper and lower stage surfaces, and compressed air is blown out from above and below to pressurize the two glass substrates while floating them in the air. By changing the temperature of the air to be blown out, heating and cooling can be performed. If the size of the glass substrate is increased to the metric size, a difference in temperature between the two glass substrates causes the two glass substrates to be bent like a bimetal due to a difference in thermal expansion. In the present invention, the temperature of the air blown out of the porous stage is adjusted while measuring the temperature of the two glass substrates by the non-contact temperature sensor, and the heating, pressurizing or cooling is performed in a state where the temperatures of the two glass substrates are the same. Pressure. The pressure applied to the glass substrate is set to be 0.4 to 0.8 atm higher than the atmospheric pressure.
Care must be taken that a pressure higher than this will cause deformation of the glass substrate.

[Thirteenth Embodiment] FIGS. 22 and 23 show that a pair of glass substrates are sandwiched by a transfer belt, and heating and pressurization and cooling and pressurization are performed while the transfer belt is kept in the air by upper and lower honeycomb ultrasonic vibration plates. The enabled device is arranged in-line. FIG. 22 is a sectional view of the device in the heating and pressurizing region. It is well known that when a mirror-polished surface is subjected to ultrasonic vibration and a flat plate is placed on the surface, the flat plate floats in the air without contacting the lower mirror surface. The present invention utilizes this phenomenon to realize heating and pressurizing and cooling and pressurizing in a state where a pair of glass substrates is sandwiched between transport belts and floated in the air. Since the conveyor belt is floating in the air, it can move smoothly. In FIG. 23, only one heating / pressing area is installed,
Tact time can be reduced by installing three or more units. By applying feedback with a sensor so that the temperatures of the upper and lower conveyor belts are the same, warpage of the glass substrate can be prevented. It is necessary to adjust the gap between the upper and lower honeycomb ultrasonic vibration plates so that the pressure applied to the glass substrate is higher than the atmospheric pressure by about 0.4 to 0.8 atm. The transport belt is made of a metallic material such as stainless steel or Hastelloy.
It is good to coat the surface with a rubber material or the like. By using an alloy having a thermal expansion coefficient close to that of a glass substrate such as 426 alloy or Kovar for the belt of the conveyance system, the thermal deformation of the glass substrate can be further suppressed. The maximum heating temperature is around 150 degrees at the glass substrate. Epoxy sealing materials that gel at 120 degrees have also been developed,
The deformation of the glass substrate can be reduced.

[0046]

By adopting the inverted V-groove type light guide plate of the present invention, the weight of the backlight can be reduced to almost half that of the conventional parallel plate type light guide plate, so that the material cost of the light guide plate can be reduced. By changing from the scattering dot system to the scattering system of the blasting treatment, the scattering film sheet, which was conventionally required, becomes unnecessary, and the overall thickness can be reduced, and the cost of the backlight can be reduced. The inverted V-groove type light guide plate can emit light from the lamp more effectively to the liquid crystal panel side than the parallel plate type light guide plate, so that a liquid crystal panel with high brightness can be realized. The use efficiency of light emitted from the lamp is improved by arranging the heat-resistant plastic which does not thermally deform even when it comes into contact with the lamp on the lamp side. Further, since the discharge current of the lamp can be increased, a bright liquid crystal panel can be manufactured.
As a result, an image having a large contrast ratio can be expressed, so that a TV set using a liquid crystal panel can be realized. An inexpensive large-screen TV set that is thinner, brighter, lighter, consumes less power, and can be manufactured than a TV set using a plasma display or a cathode ray tube.

By using the dry etching gas, the dry etching apparatus and the back channel boron plasma doping process of the present invention, a thin film transistor substrate having a metric size can be manufactured with high yield. The long-term reliability is improved, and the uniformity of the characteristics of the transistor is improved, so that the occurrence of display unevenness is reduced. Therefore, a liquid crystal panel having a metric size can be produced at low cost.

The liquid crystal cell heat / pressure bonding apparatus of the present invention enables a liquid crystal cell having a metric size to be produced without deformation defects such as warpage of a glass substrate. As a result, the liquid crystal panel of a large display device of about 30 inches to 50 inches is thinner, brighter, lighter, cheaper, and consumes less power, so that the market can be expanded as a mainstream of a super large direct-view display device. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a conventional backlight using a four-light flat light guide plate.

FIG. 2 is a cross-sectional view of a backlight using the inverted V-groove type light guide plate of the present invention.

FIG. 3 is a cross-sectional view of a backlight using the inverted V-groove type light guide plate of the present invention.

FIG. 4 is a cross-sectional view of a backlight using the inverted V-groove light guide plate of the present invention.

FIG. 5 is a cross-sectional view of a backlight using the inverted V-groove light guide plate of the present invention.

FIG. 6 is a side view of an inverted V-groove type light guide plate with side walls according to the present invention.

FIG. 7 is a side view of an inverted V-shaped white reflective film fixing plate of the present invention.

FIG. 8 is a side view of the inverted V-shaped white reflective film fixing plate of the present invention.

FIG. 9 is a side view of the inverted V-groove type light guide plate of the present invention.

FIG. 10 is a side view of an inverted V-shaped white reflective film fixing plate with a side wall according to the present invention.

FIG. 11 is a side view of an inverted V-shaped white reflective film fixing plate with a side wall according to the present invention.

FIG. 12 is a cross-sectional view of an inverted staggered thin film transistor.

FIG. 13 is a characteristic curve of an inverted staggered thin film transistor.

FIG. 14 is a plan view of a multi-chamber type vacuum plasma apparatus of the present invention.

FIG. 15 is a plan view of a multi-chamber type vacuum plasma apparatus of the present invention.

FIG. 16 is a plan view of a multi-chamber type vacuum plasma apparatus of the present invention.

FIG. 17 is a cross-sectional view of the vertical dry etcher of the present invention.

FIG. 18 is a cross-sectional view of the glass substrate floating hot air press of the present invention.

FIG. 19 is a plan view of a stage of the hot air press of the present invention.

FIG. 20 is a cross-sectional view of the glass substrate floating hot air press of the present invention.

FIG. 21 is a cross-sectional view of a backlight in which a heat-resistant plastic plate is attached to the inverted V-groove type light guide plate of the present invention.

FIG. 22 is a sectional view of an ultrasonic levitation type heating and pressing apparatus according to the present invention.

FIG. 23 is a configuration diagram of an in-line type glass substrate floating type heating / pressing / sealing apparatus according to the present invention.

[Explanation of symbols]

1 flat transparent light guide plate 2 fluorescent lamp 3 lamp holder with silver mirror film 4 white reflector film 5 diffuser film 6 prism lens film 7 polarization separation film 8 light scattering Dot 9 Inverted V-groove type transparent light guide plate (lower surface V-groove surface blast treatment) 10 Inverted V-type white reflective film 11 Light scattering blast surface (Inverted V groove surface side) 12 Light scattering blast surface ( 13 ‥‥ Inverted V-groove type transparent light guide plate (top surface side blast treatment) 14 ‥‥ Transparent light guide plate with centrally processed groove 15 ‥‥ Inverted V-groove type transparent light guide plate with both side walls 16 {inverted V-type white reflector film fixing plate 17} glass plate 18} gate electrode 19 non-doped thin film semiconductor layer 20 {phosphorous doped n ⁺ thin film semiconductor layer 21} barrier metal 22} Source / drain metal 23 {Photoresist 24} Gate insulating film 25 {Normal thin film transistor characteristic curve without back channel operation 26} Abnormal thin film transistor characteristic curve with back channel operation 27 {Shower nozzle type high frequency discharge electrode 28} Rotary susceptor 29 {Thin film semiconductor element substrate 30} Plasma reaction gas exhaust port 31 {Plasma reaction gas injection port 32} Pressurized / heated / cooled air injection port 33} Honeycomb stage 34} Combined liquid crystal cell substrate 35 ‥‥ Air blowout hole 36 ‥‥ Porous ceramic (or porous metal) A ‥‥ Maximum thickness of light guide plate B ‥‥ Minimum thickness of light guide plate 37 ‥‥ Heat-resistant transparent plastic plate 38 ‥‥ Rotation area of glass substrate susceptor 39 ‥‥ Vertical dry etching discharge area 40 ‥‥ Honeycomb diaphragm 41 ‥ Ultrasonic transducer 42 ‥‥ far infrared heater 43 ‥‥ far-infrared reflecting mirror 44 ‥‥ upper platen 45 ‥‥ lower platen C ‥‥ cooling pressure area H ‥‥ heated pressure area 46 ‥‥ crimping conveyor belt

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Claims (21)

[Claims] In a side edge lamp type backlight of a liquid crystal display device, a light guide plate made of a transparent plastic is flat on a surface on a liquid crystal panel side, and is a drawing on a surface on a side opposite to the liquid crystal panel side. The backlight has a V-shaped groove structure in which the thickness of the light guide plate at the center of the V-shaped groove is reduced, the surface on the V-groove side is blasted, and the surface is processed to have small irregularities. . 2. In a side edge lamp type backlight of a liquid crystal display device, a light guide plate made of a transparent plastic is flat on a surface on a liquid crystal panel side, and a light guide plate on a surface on a side opposite to the liquid crystal panel side is in a drawing. A backlight having a V-shaped groove structure in which the thickness of a light guide plate at the center is reduced, a flat portion on a liquid crystal panel side is blasted, and the surface is processed to have a small unevenness. . 3. The backlight according to claim 1, wherein the thickness of the thinnest portion at the center of the light guide plate is not more than 1/2 of the thickest portion near the lamp light source. Backlight featured. 4. The backlight according to claim 1, wherein a side wall is provided on each of two side edges of the light guide plate where no lamp is provided. 5. A method of manufacturing a reverse stagger type back channel etching type thin film silicon semiconductor transistor used in an active matrix liquid crystal display element, wherein a video signal wiring and a drain electrode are formed by etching and then the photoresist is not removed. A dry etching of an n ⁺ amorphous silicon layer doped with phosphorus. 6. A method of manufacturing an inverted staggered back channel etching type thin film silicon semiconductor transistor used in an active matrix liquid crystal display device, wherein when dry etching a phosphorus-doped n ⁺ layer, methane trifluoride is used. CClF _3] or method which comprises using trifluoride dibromomethane [CBrF _3] or three trifluoroiodomethane [CIF _3] as an etching gas. 7. An n ⁺ layer doped with phosphorus by mixing three types of gases, such as oxygen gas and a rare gas such as helium gas or argon gas, in addition to the halogenated methane trifluoride gas. A manufacturing method characterized by etching. 8. A method of manufacturing an inverted staggered back channel etching type thin film silicon semiconductor transistor used in an active matrix liquid crystal display element, wherein a video signal wiring and a drain electrode are formed by etching and then the photoresist is not removed. After dry etching the n ⁺ layer doped with phosphorus, the photoresist is not removed, and the back channel portion of the transistor is formed by using a mixed gas of diborane [B ₃ H ₆ ] gas and hydrogen gas [H ₂ ]. A plasma discharge treatment. 9. Concerning claim 8, the phosphorus-doped n ⁺
The chamber for dry etching the amorphous silicon layer and the chamber for plasma discharge treatment with diborane gas [B ₂ H ₆ ] and hydrogen gas [H ₂ ] in the back channel portion of the thin film transistor are different chambers, and the n ⁺ layer is dry etched. A manufacturing apparatus characterized by moving a thin film transistor substrate from a chamber to a plasma discharge processing chamber using diborane gas without breaking vacuum. 10. The method according to claim 5, wherein the n ⁺ amorphous silicon layer doped with phosphorus is dry-etched without removing the photoresist, the thin film transistor substrate is once taken out into the atmosphere, and the photoresist is removed by a plasma ashing apparatus. A manufacturing method characterized by stripping a photoresist after write ashing. 11. A chamber for dry-etching a phosphorus-doped n ⁺ layer in a channel portion of an inverted staggered back channel etching type thin film silicon semiconductor transistor used in an active matrix liquid crystal display element, the inner wall of the chamber and the glass substrate. A dry etching apparatus characterized in that the color of the inner surface of the chamber, such as a stage on which the substrate is mounted and a discharge electrode for applying a high-frequency voltage, is black or brown. 12. A dry etching apparatus according to claim 11, wherein a black material such as amorphous carbon, silicon carbide, or a composite material of carbon and aluminum is used for an inner wall, a stage, and a discharge electrode of the chamber. 13. A dry etcher for processing a thin-film silicon semiconductor layer of an active matrix liquid crystal element, wherein a high-frequency display discharge electrode has an angle of 80 to 90 degrees with respect to the horizontal.
The glass substrate is placed vertically in a range of degrees, and is horizontally transferred from a loader and then placed horizontally on a susceptor in a dry etching chamber. Thereafter, the susceptor rotates around the lower part of the susceptor until the susceptor is parallel to the discharge electrode. 14. A dry etching gas discharged from a shower nozzle of a vertically disposed discharge electrode according to claim 13, together with a reaction product, is discharged from an exhaust pipe disposed around the discharge electrode. A dry etching apparatus characterized by the following. 15. The discharge region according to claim 13, wherein the susceptor rises vertically and becomes parallel to the discharge electrode.
A structure in which the region where the susceptor rotates on the back side of the susceptor is completely spatially separated, so that the dry etching reaction gas does not flow into the space on the back side of the susceptor, and the exhaust system of the two regions is completely separated. Characteristic dry etching equipment 16. In a manufacturing process of a liquid crystal panel, when a pair of glass substrates are bonded using a sealing material, a horizontally arranged porous ceramic stage or a porous metal stage is used to bond two glass substrates. From above and below,
A thermocompression bonding apparatus characterized in that two substrates are floated in the air by blowing out hot air, and the two substrates are heated and pressed to be bonded. 17. The substrate according to claim 16, wherein after the thermosetting epoxy-based sealing material is gelled and the two substrates are completely adhered, the substrate is floated by blowing cold air from above and below the substrate instead of hot air. A crimping device characterized in that it is pressurized and cooled while it is in a pressed state. 18. A side edge lamp type backlight for a liquid crystal display device, wherein a heat-resistant transparent plastic plate is provided between the lamp and the light guide plate on an end face side of the light guide plate made of transparent plastic where the lamp is installed. Backlight characterized by scissors. 19. The backlight according to claim 1, wherein the density of the surface irregularities due to the sandblasting process is small near the lamp side, increases as approaching the center of the light guide plate, and increases at the center of the light guide plate. A backlight characterized in that: 20. In a manufacturing process of a liquid crystal panel, when a pair of glass substrates are bonded to each other using a sealing material, a horizontally arranged honeycomb vibration plate is ultrasonically vibrated by an ultrasonic vibrator, and the pair of glass substrates is put in the air. A crimping device characterized in that it is heated and pressurized in a floating state and coalesced. 21. In a manufacturing process of a liquid crystal panel, when a pair of glass substrates are bonded to each other using a sealing material, a horizontally disposed honeycomb vibration plate is ultrasonically vibrated by an ultrasonic vibrator, and the pair of glass substrates is put in the air. An apparatus in which a region to be heated and pressurized and a region to be cooled and pressurized are arranged in-line in a floating state, and the glass substrate is continuously moved while being floated and pressed.