JP2000039619A - Liquid crystal display device and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the adhesion of the material of unnecessary transparent conductive films forming transparent substrates on the surfaces on the liquid crystal side of the transparent substrates by selectively forming the transparent conductive films so as to avert roller contact parts at the time of transporting these films with the rollers. SOLUTION: A liquid crystal display panel 100 is constituted by respectively adhering polarizing plates 21, 26 to the surface (the surface on the observation side) of the transparent substrate 1A on the side opposite to an liquid crystal layer LC and the surface (the surface on a back light unit 300 side) of the transparent substrate 1B on the side opposite to the liquid crystal layer LC. More particularly the transparent conductive films 30 are formed between the polarizing plate 21 to be adhered to the transparent substrate 1A and the transparent substrate 1A. The transparent conductive films 30 are formed at least in the respective pixel regions exclusive of the entire area at the peripheral edge of the transparent substrate 1A. In such a case, the transparent conductive films 30 are selectively formed to evade the transparent conductive films 30 at the points where the rollers of the transparent substrate come into contact, by which the transfer of foreign matter adhered to the rollers to the transparent conductive films 30 may be averted.

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, for example, to a so-called horizontal electric field type liquid crystal display device.

[0002]

2. Description of the Related Art In a so-called in-plane switching type liquid crystal display device, a pixel electrode and a pixel electrode are provided in each pixel region on one liquid crystal side of a transparent substrate disposed opposite to each other via a liquid crystal. An opposing electrode is provided at a distance, and the light transmitted through the liquid crystal is modulated by an electric field generated between the pixel electrode and the opposing electrode in parallel with the transparent substrate. Such a liquid crystal display device is disclosed in, for example, Japanese Patent Application Laid-Open No. 5-505247,
The details are described in JP-A-21907 and JP-A-6-160878. In a liquid crystal display device having such a configuration, the electric field generated between the pixel electrode and the counter electrode is easily affected by external static electricity or the like. It has been known that a transparent conductive film having a function is applied.

[0003]

However, such a liquid crystal display device has one of the transparent substrates (either a transparent substrate on which a thin film transistor or the like is formed or a transparent substrate on which a color filter or the like is formed). It has been pointed out that when a transparent conductive film having a shielding function is formed by using, for example, a sputtering apparatus, the material of the transparent conductive film may wrap around the back surface. In this case, assuming that it is an ideal state that an electric field is generated only between the pixel electrode and the counter electrode, the electric field is disturbed by the material of the transparent conductive film (the pixel electrode and the material). An electric field is also generated between them), which makes it impossible to perform appropriate display. Further, the transparent substrate on which the transparent conductive film is formed is usually transported by a roller to an apparatus for performing the next step. In this case,
The roller is conveyed so that the roller comes into contact with the surface on which the transparent conductive film is formed. The surface on which the transparent conductive film is not formed is finely processed on the liquid crystal side surface, and even if not, fine processing is performed thereafter. Because there is no. However, in this case, the foreign matter adhered to the roller may be transferred to the transparent conductive film, and the stain on the display surface cannot be avoided.

The present invention has been made in view of such circumstances, and an object thereof is to provide a liquid crystal display device in which an unnecessary material of a transparent conductive film does not adhere to a liquid crystal side surface of a transparent substrate. It is in. Another object is to provide a liquid crystal display device in which the transparent conductive film on the display surface is free from contamination.

[0005]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows. Means 1. A liquid crystal display comprising: a step of forming a transparent conductive film on one surface of one of the transparent substrates disposed to face each other via a liquid crystal; and a step of roller-transporting the transparent substrate on which the transparent conductive film is formed. In the method for manufacturing an apparatus, the transparent conductive film formed on the transparent substrate is selectively formed so as to avoid a roller abutting portion during roller conveyance. In the manufacturing method of the liquid crystal display device configured as described above, since the transparent conductive film formed on the transparent substrate does not contact the roller when the transparent substrate is transported by the roller, the transparent conductive film adheres to the roller. The transferred foreign matter is not transferred to the transparent conductive film.

Means 2. A liquid crystal display device in which pixels are formed on a liquid crystal side surface of a transparent substrate opposed to each other via a liquid crystal and a transparent conductive film is formed on at least one transparent substrate on a surface opposite to the liquid crystal. Wherein the transparent conductive film is formed in at least each pixel region except for an edge of the transparent substrate. In the liquid crystal display device configured as described above, the transparent conductive film formed on the transparent substrate is selectively formed.
This makes it possible to prevent the material of the transparent conductive film from adhering to other regions (including the rear surface side of the transparent substrate).

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the liquid crystal display device according to the present invention will be described below with reference to the drawings. [Liquid Crystal Display] FIG. 1 shows a liquid crystal display panel (backlight unit 30) provided in a liquid crystal display according to the present invention.
FIG. 3 is a cross-sectional view showing one embodiment (also showing 0). In the figure, a liquid crystal display panel 100 has a transparent substrate 1B and a transparent substrate 1A which are arranged to face each other via a liquid crystal layer LC as an envelope. In this embodiment, the main surface side of the transparent substrate 1A is an observation side. ing. Therefore, the transparent substrate side 1
A backlight unit 300 is arranged on the B side, and uniform light from the backlight unit 300 side irradiates substantially the entire area of the transparent substrate 1B.

The liquid crystal layer LC interposed between the transparent substrates 1A and 1B is arranged in a matrix in the direction in which the layers spread together with the electronic circuits formed on the liquid crystal layer LC side of each transparent substrate. A plurality of pixels are configured. A set of these pixels arranged in a matrix form a display area when viewed from the transparent substrate 1A side. Each pixel constituting the display area independently controls the transmittance of light from the backlight unit 300 by the supply of a signal through the electronic circuit. Arbitrary images can be displayed in the area. Here, the control of light transmission in each pixel employs a so-called lateral electric field method in which an electric field generated in the liquid crystal layer LC in each pixel is generated in parallel with the surface of the transparent substrate. The detailed configuration of the liquid crystal display panel 100 using the horizontal electric field method and its peripheral circuits will be described later.

The liquid crystal display panel 100 of the in-plane switching mode configured as described above has a surface (observation side) of the transparent substrate 1A opposite to the liquid crystal layer LC and a liquid crystal layer LC of the transparent substrate 1B.
Surface opposite to (backlight unit 300 side)
, Polarizing plates 21 and 26 are respectively attached. In particular, a transparent conductive film (for example, ITO: Indium-Tin-Oxide) 30 is formed between the polarizing plate 21 attached to the transparent substrate 1A and the transparent substrate 1A. It functions as a conductive layer that shields against electrostatic charges such as static electricity. In this case, the transparent conductive film 30 is formed in at least each pixel region except for the entire periphery of the transparent substrate 1A. That is, the transparent conductive film 30 is a conductive film selectively formed on the transparent substrate 1A. When this conductive film is formed by, for example, a sputtering thin film forming apparatus or the like, the material of the conductive film is the same as that of the transparent substrate 1A. It is designed to prevent it from going around the back.

Next, a detailed configuration of an embodiment of a liquid crystal display device including the above-described in-plane switching mode liquid crystal display panel 100 and its peripheral driving circuit will be described. In FIG. 2, there is a so-called active matrix type liquid crystal display panel 100 first. This liquid crystal display panel 100
The display unit is constituted by a set of a plurality of pixels arranged in a matrix, and each pixel independently modulates the transmitted light from the backlight unit 300 arranged at the back of the liquid crystal display panel 100. It is configured to be controllable. The light modulation in each pixel employs a method called a lateral electric field method, and the structure thereof will be described later in detail, but the light modulation is generated in a liquid crystal layer interposed between transparent substrates arranged to face each other. The electric field is parallel to the transparent substrate. Such a liquid crystal display panel 1
00 is known as being excellent in a so-called wide-angle field of view, which allows a clear image to be recognized even when viewed from a large angle field of view on the display surface.

That is, there is a liquid crystal display panel 100,
One of the transparent substrates 1A and 1B disposed opposite each other via the liquid crystal of the liquid crystal display panel 100.
The scanning signal line 2 and the reference signal line 4 which extend in the x direction (row direction) and are juxtaposed in the y direction (column direction) are formed on the surface on the liquid crystal side. In this case, in the same figure, from above the transparent substrate 1B, a scanning signal line 2, a reference signal line 4 close to the scanning signal line 2, a scanning signal line 2 relatively separated from the reference signal line 4, The scanning signal lines 2 and the reference signal lines 4 adjacent to each other are sequentially arranged. Further, a video signal line 3 which is insulated from the scanning signal line 2 and the reference signal line 4 and extends in the y direction and is juxtaposed in the x direction is formed.

Here, a unit pixel is formed in each of a relatively large rectangular area surrounded by the scanning signal line 2, the reference signal line 4, and the video signal line 3, and these unit pixels are formed. Are arranged in a matrix to form a display surface. The detailed configuration of this pixel will be described below.

The liquid crystal display panel 100 is provided with a vertical scanning circuit 5 and a video signal driving circuit 6 as external circuits, and the vertical scanning circuit 5 sequentially applies a scanning signal (voltage) to each of the scanning signal lines 2. Is supplied, and a video signal (voltage) is supplied from the video signal drive circuit 6 to the video signal line 3 in accordance with the timing. Note that the vertical scanning circuit 5 and the video signal driving circuit 6
Are supplied with power from the liquid crystal drive power supply circuit 7 and image information from the CPU 8 is divided into display data and control signals by the controller 9 and input. In addition, the liquid crystal display panel 100 having the above-described configuration is particularly provided with a reference signal line 4, and a reference voltage signal applied to the reference signal line 4 is also supplied from the liquid crystal drive power supply circuit 7.

FIG. 3 is a plan view showing an embodiment of the unit pixel (corresponding to an area surrounded by a dotted line in FIG. 2). FIG. 4 is a sectional view taken along line IV-IV in FIG. 3, FIG. 5 is a sectional view taken along line VV, and FIG. 6 is a sectional view taken along line VI-VI in FIG.
Is shown in In FIG. 3, a reference signal line 4 extending in the x direction and a scanning signal line 2 relatively parallel to and substantially separated from the reference signal line 4 in the (-) y direction are formed on the main surface of the transparent substrate 1B. Have been.

Here, three reference electrodes 14 are formed integrally with the reference signal line 4. That is, two of the reference electrodes 14 are in the y-direction side of a pixel region formed by a pair of video signal lines 3 described later, that is, in the (-) y direction in proximity to the respective video signal lines 3. It is formed to extend to the vicinity of the scanning signal line 2, and the other one is formed between them.

On the surface of the transparent substrate 1B on which the scanning signal line 2, the reference signal line 4, and the reference electrode 14 are formed, the insulating film 15 made of, for example, a silicon nitride film covers the scanning signal line 2 and the like. (See FIGS. 4, 5, and 6)
Are formed. The insulating film 15 serves as an interlayer insulating film for an intersection with the scanning signal line 2 and the reference signal line 4 for a video signal line 3 described later, and a thin film transistor T
It functions as a gate insulating film for the region where the FT is formed and as a dielectric film for the region where the storage capacitor Cstg is formed.

First, the semiconductor layer 16 is formed on the surface of the insulating film 15 in the region where the thin film transistor TFT is formed.
Are formed. The semiconductor layer 16 is made of, for example, amorphous Si, and is formed on the scanning signal line 2 so as to overlap a portion close to the video signal line 3. As a result, a part of the scanning signal line 2 is
Is also configured as a gate electrode. Then, on the surface of the insulating film 15 thus formed, as shown in FIG. 3, the video signal lines 3 extending in the y direction and juxtaposed in the x direction are formed. And the video signal line 3 is
A drain electrode 3A extending to a part of the surface of the semiconductor layer 16 of the thin film transistor TFT is integrally provided.

Further, a display electrode 18 is formed on the surface of the insulating film 15 in the pixel region. This display electrode 1
Reference numeral 8 is formed so as to run between the reference electrodes 14. That is, one end of the display electrode 18 also serves as the source electrode 18A of the thin film transistor TFT, extends in the (+) y direction as it is, further extends in the x direction along the reference signal line 4, and then (-) It has a U-shape extending in the direction and having the other end. In this case, the display electrode 1
The portion superimposed on the reference signal line 8 constitutes a storage capacitor Cstg including the insulating film 15 as a dielectric film between itself and the reference signal line 4. This storage capacity Cstg
Thus, for example, when the thin film transistor TFT is turned off, an effect of storing video information on the display electrode 18 for a long time is exerted.

The surface of the semiconductor layer 16 corresponding to the interface between the drain electrode 3A and the source electrode 18A of the thin film transistor TFT described above is doped with phosphorus (P) to form a high concentration layer. Ohmic contact at the electrode is achieved. In this case, the high concentration layer is formed on the entire surface of the semiconductor layer 16,
After each of the electrodes is formed, the above structure can be obtained by etching the high-concentration layer other than the electrode formation region using the electrodes as a mask.

Then, as described above, the thin film transistor TF
T, video signal line 3, display electrode 18, and storage capacitor Cs
On the upper surface of the insulating film 15 on which the tg is formed, a protective film 19 made of, for example, a silicon nitride film (see FIGS. 4, 5, and 6)
Is formed, and an alignment film 20 is formed on the upper surface of the protective film 19 to constitute the transparent substrate 1A of the liquid crystal display panel 100. A polarizing plate 21 is disposed on the surface of the transparent substrate 1A opposite to the liquid crystal layer.

As shown in FIG. 4, a black matrix 22 is formed on a portion of the transparent substrate 1A on the liquid crystal side at a portion corresponding to a boundary between the pixel regions. This black matrix 22 is formed by the thin film transistor TF
It has a function of preventing direct light irradiation to T and a function of improving display contrast. The black matrix 22 is formed in a region indicated by a broken line in FIG. 3, and an opening formed therein constitutes a substantial pixel region. From this,
The display area is substantially a collective area of pixels surrounded by the black matrix.

Further, a color filter 23 is formed so as to cover the opening of the black matrix 22. The color filter 23 has a color different from that of the pixel region adjacent in the x direction and has a boundary on the black matrix 22. Part. An overcoat film 24 made of a resin film or the like is formed on the surface on which the color filters 23 are formed, and an alignment film 25 is formed on the surface of the overcoat film 24. Note that a polarizing plate 26 is disposed on a surface of the transparent substrate 1B opposite to the liquid crystal layer side via a transparent conductive film 30.

The liquid crystal display device of the above-described embodiment is
Black matrix 22 or color filter layer 23
Is used as the upper transparent substrate (substrate farther from the backlight), but can also be applied to a substrate using the transparent substrate provided with each electrode and the thin film transistor TFT as the upper transparent substrate. . in this case,
The transparent conductive film 30 is formed by the thin film transistor TF
An upper transparent substrate on which T and the like are formed. Also in this case, since it is possible to eliminate the wraparound on the back surface side of the transparent conductive film, there is an effect that an inconvenience such as a short circuit between the electrodes can be eliminated.

[Manufacturing Method 1] FIG. 7 is an explanatory view showing an embodiment of a method of manufacturing the upper transparent substrate 1A. First, there is a transparent substrate 40. The transparent substrate 40 is a so-called four transparent substrate for forming the upper transparent substrate 1A of the four liquid crystal display devices. That is, after passing through one step in the transparent substrate 40, the transparent substrate 40 is cut along the dashed line in the figure and divided, and goes through a step of assembling each liquid crystal display device. As shown in FIG. 4, a black matrix layer 22, a color filter layer 23, an overcoat film 24, a region of each upper transparent substrate 1A (a region surrounded by a dashed line) on the back surface of the transparent substrate 40 in the drawing. And an alignment film 25 are formed.

Then, the area of each upper transparent substrate 1A on the surface of the transparent substrate 40 (the area surrounded by the dashed line).
7, a transparent conductive film 30 is formed as shown in FIG. In this case, the transparent conductive film 30 is formed in at least each pixel region except for the entire periphery of the edge of each upper transparent substrate 1A. This transparent conductive film is formed, for example, by a sputtered thin film manufacturing apparatus or the like, which will be described in detail later. At this time, the transparent conductive film is selectively formed on a region using a mask jig provided in the sputtered thin film manufacturing apparatus. It has become.

The thus formed transparent conductive film 30
Is formed without going around the back surface of the transparent substrate 40,
Accordingly, the transparent substrate 40 is formed without any conductive material on the rear surface. This means that, in the liquid crystal display device including each upper transparent substrate 1A cut from the transparent substrate 40, the electric field from the pixel electrode 18 generated in the liquid crystal terminates only on the counter electrode 14 side,
Disturbance of the electric field distribution due to termination on the conductive material side does not occur.

Further, the transparent substrate 40 on which the transparent conductive film 30 is formed is subjected to the next step, and is transported by a roller as shown in FIG. Is normal. In FIG. 8, in order to clarify the positional relationship between the transparent conductive film 30 and each roller 42, the back surface of the transparent substrate 40 is drawn upside down. Actually, the surface on which the transparent conductive film 30 is formed is arranged so as to face each roller 42 side. In this case, by selectively forming the transparent conductive film 30 so as to avoid the transparent conductive film 30 at a position where the roller 42 of the transparent substrate 40 abuts, foreign matter adhering to the roller 42 is removed. Transfer to the transparent conductive film 30 can be avoided.

In the above manufacturing method, the processing on the front surface and the processing on the back surface of the transparent substrate 40 are performed as follows.
It goes without saying that either may take precedence. When the conductive material is scattered during the formation of the transparent conductive film 30 on the surface of the transparent substrate 40 and adheres to the back surface of the transparent substrate 40, for example, whether or not the alignment film 25 is formed, This is because the material causes distortion of the distribution of the electric field, and the inconvenience is not solved.

In the above-described embodiment, the transparent conductive film 30 is selectively formed in a region other than the periphery of each transparent substrate 1A to be cut. However, for the purpose of preventing the transfer of foreign matter by the roller of the transparent conductive film 30 only, as shown in FIG. 9, the transparent conductive film 30 is selectively formed by avoiding only the contact portion of the roller 42. It goes without saying that this may be done. Further, in the above embodiment, 4
Although the description has been made on the transparent substrate 40 which is a single sheet,
The present invention is not necessarily limited to this, and it goes without saying that the present invention can be applied to the case of taking two sheets or taking one sheet.

[Sputtered Thin Film Manufacturing Apparatus] FIGS. 10A and 10B are configuration diagrams showing one embodiment of the above-described sputtered thin film manufacturing apparatus. FIG. 10A is a plan view, and FIG. B
It is sectional drawing in the -b line. In the figure, first, a back plate 50 constituting a part of a vacuum vessel (not shown)
There is. A target assembly 52 is, for example, bolted to the upper surface of the back plate 50. This target assembly 52 includes:
A target 52B is bonded to a backing plate 52A having a water cooling function, for example. On a surface of the back plate 50 opposite to the target assembly 52 side, a permanent magnet 54 swinging along the surface is arranged. Further, a susceptor 56 is disposed in the vacuum vessel so as to face the target assembly 52,
The transparent substrate 40 is indicated on the surface of the susceptor 56 on the side of the target assembly 52 by, for example, vacuum suction. A mask jig 58 is arranged on the surface of the transparent substrate 40 on the side of the target assembly 52. The mask jig 58 applies the material of the target 52B only to a selected region of the transparent substrate 40. It can be sputtered.

That is, as shown in FIG. 3A, the mask jig 58 is provided on the upper transparent substrate 1A with respect to four transparent substrates 40 in a portion corresponding to a portion excluding the peripheral edge thereof. Is formed of a conductive layer having an opening. In this case, the mask jig 58 is provided with an opening corresponding to the case where the transparent substrate is, for example, a two-sheet or one-sheet substrate, and can be selectively mounted. Nor. After introducing Ar gas into the vacuum vessel at a predetermined pressure, the target 5
By applying a DC voltage from a DC power supply to 2B, plasma is generated near the surface of the target 52B of the permanent magnet 54, and the target 5 exposed to the plasma is generated.
Sputtered particles protruding from the surface of 2B are used as mask jig 5
8 on a transparent substrate.

As shown in FIG. 7, a transparent conductive film 30 is formed on each upper transparent substrate 1A.
The transparent conductive film 30 is not formed on the other portion except the peripheral portion, and the other portion is not attached. This means that the material of the transparent conductive film is applied only to the region shown in FIG. Therefore, the electric field between the pixel electrode 18 and the counter electrode 14 is not disturbed by the material of the transparent conductive film.

In the above description, the reason why the transparent conductive film 30 is prevented from being applied to the entire periphery of each upper transparent substrate 1A is that the upper transparent substrate 1A is separated from the transparent substrate 40 by cutting. At this time, it is to prevent chips generated by cutting the transparent conductive film 30 from adhering to the back side of the transparent substrate 1A. However, this is not always the case. For example, as shown in FIG.
The attachment of the transparent conductive film 30 may be avoided over the entire area around the periphery of the zero. The transparent conductive film 30 is formed at a part of the periphery of each of the separated transparent substrates 1 </ b> A, because the transparent conductive film 30 has an effect of preventing the material particles of the transparent conductive film 30 from wrapping around the back surface of the transparent substrate 40. is there.

[Manufacturing Method 2] FIG. 12 is an explanatory view showing another embodiment of a method of manufacturing the upper transparent substrate 1A.
FIG. 3A is a side view, and FIG.
FIG. 4 shows a cross-sectional view taken along line b. First, the apparatus for manufacturing a sputtered thin film used in the present embodiment is capable of accommodating a plurality of transparent substrates 1A, and these transparent substrates can be arranged substantially in a vertical plane by a jig. Here, one transparent substrate 1A is shown, but the present invention is not limited to this, and it goes without saying that a plurality of transparent substrates may be used. The transparent conductive material is scattered from one surface (the surface opposite to the liquid crystal side) of each transparent substrate 1A.

FIG. 3A shows, for example, three transparent substrates 1A arranged side by side by the jig, each of which is supported by a substrate holding pawl 62 provided on the frame body 60. I have. In the area inside the frame body 60, a wraparound preventing jig 64 is arranged close to the rear side of each transparent substrate 1A. In addition, the surrounding prevention jig 64 is provided with an opening smaller than this region in a region facing each transparent substrate 1A, and the periphery of this opening is opposed to the transparent substrate 1A. In other words, the surrounding prevention jig 64 is formed not only on the outer peripheral portion of each transparent substrate 1A but also on the back surface around the transparent substrate 1A. Such a transparent substrate 1
The transparent conductive material is deposited on the transparent substrate 1A between the transparent substrates 1A when the transparent conductive material scatters toward the transparent substrate 1A side (more specifically, the outer peripheral portion of each transparent substrate 1A). The transparent conductive material scattered around the transparent substrate 1 is obtained by the wraparound preventing jig 64, and hardly wraps around the back surface of the transparent substrate 1A of the remaining transparent conductive material. The transparent substrate 1A thus coated with the transparent conductive material
In one aspect, the transparent conductive material is applied over the entire area on one side, but the surrounding area of the transparent conductive material can be significantly suppressed on the other side.

[Consideration of completed liquid crystal display] FIG. 10
Alternatively, the transparent substrate 1A formed by the method shown in FIG.
Then, a lower transparent substrate of the liquid crystal display device is formed, and the liquid crystal display device is completed by facing the upper transparent substrate shown in FIG. In this liquid crystal display device, since the transparent conductive material is prevented from spreading around the liquid crystal side of the transparent substrate 1A on which the transparent conductive film is formed, unevenness is not visually recognized on the display. It is confirmed that.

As described above, when the transparent conductive material wraps around the liquid crystal side of the transparent substrate 1A, the electric field generated in each pixel is disturbed, thereby causing display unevenness. Then, by disassembling the liquid crystal display device thus completed, only the transparent substrate 1A is taken out, and the color filter, black matrix, and overcoat film formed on the liquid crystal side are fired (at 500 ° C.).
(For about 4 hours at the following temperature) to expose the surface of the display area of the transparent substrate 1A, and Auger analysis was performed on the surface.

Here, Auger analysis is an analysis method in which an electron beam is applied to a sample to measure the energy and amount of Auger electrons peculiar to an excited and emitted element. That is, when the solid surface is irradiated with an electron beam, an electron called an Auger electron is generated from the irradiation point together with secondary electrons and reflected electrons.
Auger electrons have energy peculiar to solid constituent elements, and their generation region is about 2 nm or less from the surface. Therefore, if an Auger electron is detected and its energy is measured, the element located on the very surface of the solid can be measured.

In this measurement, as shown in FIG. 13, the display area of the transparent substrate 1A (the color filter, the black matrix, and the overcoat film are removed, and the transparent substrate 1A is removed).
A where the glass surface of A was exposed), Auger analysis was performed at each position indicated by, in order from the outer contour. Exact coordinates of each position (unit: m
m) is as shown in the figure.

FIG. 14 shows one of the data obtained in this manner, and shows the data at the respective positions indicated by the above in order from the top. Here, in each of these data, the horizontal axis represents the irradiation energy, and the vertical axis represents the Auger electron intensity (dN / dE (N: amount)).
As can be seen from the drawing, In / O is 9.2% at the data at the position, and In / O is 0.0% at the data at each position. From this, In / O at a position where the metal atoms are considered to be the largest is an extremely small value of 9.2%. This means that this In
The number of metal atoms according to the value of / O means that the display unevenness due to the disturbance of the electric field caused by these factors is so small that it cannot be visually recognized at all.

FIG. 15 shows data obtained in the same manner for the other transparent substrate 1A. Similarly, FIG. As is clear from the figure, In / O is 83.3% at the data at the position, and In / O is 6.2% at the data at the position. O is 0.0%.

Here, from the above data and other data (not shown), the relationship between the amount of the transparent conductive material and the presence or absence of display unevenness that can be visually recognized is considered.
A graph as shown in FIG. 16 can be obtained. FIG. 14 shows a case where a plurality of liquid crystal display devices of the same type are disassembled, each transparent substrate 1A is taken out, and the surface (glass surface) of the transparent substrate 1A in the display area is exposed. 6 is a graph showing the results of Auger analysis only. In this graph, the data of only the portion corresponding to is particularly adopted because it is usually the case that the metal atoms are wrapped around at the most locations and less at other locations. It is based on the idea of From the figure, it is clear that the amount of metal atom wraparound in which display unevenness can be visually recognized is 83.3% or more. From this, if it is less than 83.3%,
Display unevenness can be reduced as compared with the related art. For this reason, in order to further improve the display quality of the liquid crystal display device, a liquid crystal display device in which the amount of wraparound of metal atoms is specified to be less than 40.0% or less than 38.5% to reduce display unevenness is obtained. Needless to say, this may be done.

In forming the transparent conductive film, the metal atoms of the material of the transparent conductive film go around not only around the transparent substrate 1A but also suddenly, for example, in the center of the display area. There may be cases. Therefore, it is preferable that the ratio of the metal element to oxygen by Auger analysis be less than 83.3%, less than 40.0%, or less than 38.5% over the entire display region. Needless to say.

However, in consideration of the low probability of the above-mentioned sudden occurrence of the wraparound of metal atoms and the difficulty of performing Auger analysis over the entire display region, each of the four corners of the display region is considered. Only an Auger analysis is performed, and if the ratio of the metal element to oxygen is less than 83.3%, or less than 40.0%, or less than 38.5%, a liquid crystal display device without display unevenness is frequently used. Of course. For the same reason, the ratio of the metal element to oxygen is 3
Less than 7.5%, less than 36.5%, less than 35.5%, 3
Needless to say, it may be less than 4.5%, less than 33.5%,.

[Consideration of Transparent Substrate when Transparent Conductive Film is Formed] The transparent substrate 1A (formed with a color filter, a black matrix, and an overcoat film still formed) by the method shown in FIG. 10 or FIG. ) Was used as a sample, and the material on the liquid crystal side was analyzed by Auger analysis.

FIG. 17 is a view corresponding to FIG. 12, in which one of the transparent substrates 1A was taken out after the formation of the transparent conductive film, and Auger analysis was performed at the positions indicated by, respectively. In this case, the periphery including the location of the transparent substrate 1A is an area to be separated in a later step. Then, a location is determined on the cut transparent substrate 1A so as to match the outer contour of the display area.

FIG. 18 is data showing the result of the Auger analysis. In the figure, In / O is 39.4% for data at the position, and 21.2% for data at the position. Such a transparent substrate 1A is then formed with a color filter, a black matrix, and an overcoat film on the surface subjected to Auger analysis to form a lower transparent substrate, and is opposed to the upper transparent substrate shown in FIG. Further, a liquid crystal display device is completed by enclosing the liquid crystal. This liquid crystal display device
Since the surrounding of the transparent conductive material on the liquid crystal side of the transparent substrate 1A on which the transparent conductive film is formed can be largely suppressed,
It is confirmed that the display unevenness is not visually recognized.

FIG. 19 shows one of the other data obtained in the same manner. Similarly, FIG. 19 shows the data at the positions indicated by the above in order from the top. As is clear from the figure, the data at the position is 92.1% In / O, and the data at the position is 38.5% In / O.

Here, the relationship between the amount of the transparent conductive material and the presence or absence of display unevenness that can be visually recognized by the completed liquid crystal display device is considered from the above data and other data (not shown). A graph as shown in FIG. FIG. 3 is a graph showing the Auger analysis results measured in the surrounding area, that is, at the above-mentioned location in each of the plurality of transparent substrates 1A on which the transparent conductive material is formed. From the figure, it is clear that the amount of metal atom wraparound in which display unevenness can be visually recognized is 92.1% or more. From this, if it is less than 92.1%, display unevenness is reduced as compared with the conventional case. It can be reduced.

Here, it is sufficient that the value of the amount of metal atoms wrap around the entire area around the transparent substrate 1 is less than 92.1%. If it is confirmed that the value is smaller than the above value, it can be determined that the value is smaller than the value in the entire area around the transparent substrate 1. This is because it can easily be estimated that the amount of metal atoms wrapped around is the largest at the four corners of the transparent substrate 1.

As is clear from FIG.
It can be seen that, at the point (i), that is, at the point that coincides with the outer contour of the display area, the display unevenness can be reduced as compared with the conventional case when the amount of the metal atom wraparound is 38.5%. This means that the area around the metal atoms may be less than 38.5% in the area to be configured as the display area of the transparent substrate 1.

For this reason, by using the transparent substrate 1 in which the amount of metal atoms wrapping around in the display area is less than 38.5% as an envelope of the liquid crystal display device, it is possible to obtain a display having no display unevenness. become able to. Naturally, the amount of wraparound of metal atoms is less than 37.5%, 3
Less than 6.5%, less than 35.5%, less than 34.5%, 3
Needless to say, it may be less than 3.5,.

As is clear from the above description, the result of Auger analysis of the transparent substrate 1A on which the color filter, the black matrix and the overcoat film have not yet been formed is the transparent substrate obtained by disassembling the liquid crystal display device. It is considered that the reason for the difference from 1A is that some of the impurities are not removed or oxygen is not added by baking the color filter, the black matrix, and the overcoat film.

[Other Embodiments] When the transparent conductive material wraps around the liquid crystal side of the transparent substrate during the formation of the transparent conductive film is so small that display unevenness in the display area cannot be recognized, the Auger analysis is performed. It can be seen from each of the data that the ratio of metal atoms is lower than that of oxygen. For this reason, it goes without saying that even with a transparent substrate having such an Auger analysis result and a liquid crystal display device including the transparent substrate, display unevenness can be reduced. In addition, it can be seen that the data obtained by Auger analysis commonly have carbon atoms equal to or higher than In. For this reason, it goes without saying that even with a transparent substrate having such an Auger analysis result and a liquid crystal display device including the transparent substrate, display unevenness can be reduced. In the above-described embodiment, In is used as the metal molecule of the transparent conductive material, and the result of Auger analysis is shown. However, since different transparent conductive materials have different metal molecules, it is needless to say that Sn, Al, Cr, Ta, Mo, W, etc. may be used without being limited to In. In the above-described embodiment, the apparatus for manufacturing a sputtered thin film is used for forming the transparent conductive film 30, but the invention is not necessarily limited to such an apparatus. Any device can be used as long as it can atomize the transparent conductive material and scatter it. In the above-described embodiment, a so-called in-plane switching mode liquid crystal display device has been described. However, it is needless to say that the present invention can be applied to a case where a transparent conductive layer is formed on the surface of a transparent substrate, even in a so-called vertical electric field type.

[0055]

As is apparent from the above description,
According to the liquid crystal display device of the present invention, unnecessary adhesion of the material of the transparent conductive film to the surface of the transparent substrate on the liquid crystal side can be avoided. Further, according to the method of manufacturing a liquid crystal display device according to the present invention, it is possible to prevent the transparent conductive film on the display surface from being stained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a liquid crystal display device according to the present invention.

FIG. 2 is an equivalent circuit diagram showing one embodiment of a liquid crystal display device according to the present invention.

FIG. 3 is a plan view showing one embodiment in a pixel region of the liquid crystal display device according to the present invention.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a sectional view taken along line VV of FIG. 3;

FIG. 6 is a sectional view taken along line VI-VI in FIG.

FIG. 7 is an explanatory view showing one embodiment of a method for manufacturing a liquid crystal display device according to the present invention.

FIG. 8 is an explanatory view showing the effect of the method for manufacturing a liquid crystal display device according to the present invention.

FIG. 9 is an explanatory view showing another embodiment of the method of manufacturing the liquid crystal display device according to the present invention.

FIG. 10 is a configuration diagram showing an embodiment of a sputtering thin film forming apparatus used in the method for manufacturing a liquid crystal display device according to the present invention.

FIG. 11 is an explanatory view showing another embodiment of the method of manufacturing the liquid crystal display device according to the present invention.

FIG. 12 is an explanatory view showing another embodiment of the method of manufacturing the liquid crystal display device according to the present invention.

FIG. 13 is an explanatory view showing a place where Auger analysis is performed on a transparent substrate of the liquid crystal display device according to the present invention.

FIG. 14 is a graph showing the result of Auger analysis of a transparent substrate of a liquid crystal display according to the present invention.

FIG. 15 is a graph showing another result of Auger analysis of a transparent substrate of a liquid crystal display according to the present invention.

FIG. 16 is another graph showing the result of Auger analysis of the transparent substrate of the liquid crystal display according to the present invention.

FIG. 17 is an explanatory view showing a place where Auger analysis is performed on a transparent substrate according to the present invention.

FIG. 18 is a graph showing the result of Auger analysis of a transparent substrate according to the present invention.

FIG. 19 is a graph showing the results of Auger analysis of a transparent substrate according to the present invention.

FIG. 20 is another graph showing the result of Auger analysis of a transparent substrate according to the present invention.

[Explanation of symbols]

1A, 1B: transparent substrate, 30: transparent conductive film, 42: roller, 58: mask jig.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Ryo Yamaoka 3300 Hayano, Mobara-shi, Chiba Electronic Device Division, Hitachi, Ltd. Inside

Claims (25)

[Claims] 1. A step of forming a transparent conductive film on one surface of one of transparent substrates arranged to face each other via a liquid crystal, and a step of carrying a roller on the transparent substrate on which the transparent conductive film is formed. Wherein the transparent conductive film formed on the transparent substrate is selectively formed so as to avoid a roller contact portion during roller conveyance. Production method. 2. The method according to claim 1, wherein the transparent conductive film formed on the transparent substrate is formed by partially masking the transparent conductive material when the transparent conductive material is scattered. Method. 3. Pixels are formed on a liquid crystal side surface of a transparent substrate opposed to each other via a liquid crystal, and a transparent conductive film is formed on at least one transparent substrate on a surface opposite to the liquid crystal. The liquid crystal display device according to claim 1, wherein the transparent conductive film is formed in at least each pixel region except for an edge of the transparent substrate. 4. The method according to claim 3, wherein the transparent conductive film formed on the transparent substrate is formed by being partially masked when the transparent conductive material is scattered and deposited. Liquid crystal display. 5. A transparent substrate, and a transparent conductive film formed in a display region on a side opposite to the liquid crystal side of the transparent substrate, wherein a surface of the transparent conductive material of the transparent conductive film on a liquid crystal side of the transparent substrate. A liquid crystal display device characterized in that the amount of wraparound is so small that display unevenness in the display area cannot be recognized. 6. The method according to claim 5, wherein the ratio of metal atoms is lower than oxygen atoms by Auger analysis on the exposed surface of the transparent substrate in a display region on the liquid crystal side of the transparent substrate. The liquid crystal display device as described in the above. 7. A transparent substrate having a transparent conductive film formed on a side opposite to a liquid crystal side, wherein a surface of the transparent substrate on which the transparent conductive film is formed in a display region on a liquid crystal side is subjected to Auger analysis. A liquid crystal display device, wherein the ratio of metal atoms to oxygen atoms is less than 83.3%. 8. A transparent substrate, comprising: a pair of transparent substrates opposed to each other with a liquid crystal interposed therebetween; and an organic film formed on one of the transparent substrates on the liquid crystal side, after removing the organic film. Wherein the ratio of metal atoms to oxygen atoms is less than 83.3% by Auger analysis in the display region of (1). 9. A color filter, comprising: a pair of transparent substrates opposed to each other via a liquid crystal; and a color filter, a black matrix, and an overcoat film formed on one of the transparent substrates on the liquid crystal side. A liquid crystal display device wherein the ratio of metal atoms to oxygen atoms is less than 40.0% by Auger analysis in the display region of the transparent substrate after removing the black matrix and the overcoat film. 10. A color filter, a black matrix, and an overcoat film formed on a liquid crystal side of one of the transparent substrates, and the color filter, the black matrix, and the overcoat film. A liquid crystal display device wherein the ratio of metal atoms to oxygen atoms is less than 38.5% by Auger analysis in the display region of the transparent substrate after the removal. 11. A transparent substrate, comprising: a pair of transparent substrates opposed to each other with a liquid crystal interposed therebetween; and an organic film formed on one of the transparent substrates on the liquid crystal side, and after removing the organic film. Wherein the ratio of metal atoms to oxygen atoms is less than 9.2% by Auger analysis in the display region of (1). 12. The method according to claim 12, wherein the color filter, the black matrix and the overcoat film are removed by removing the transparent substrate.
The liquid crystal display device according to any one of claims 9 and 10, wherein the liquid crystal display device is fired at a temperature of 00 ° C or less. 13. The method according to claim 8, wherein the organic film is one of a color filter and a black matrix, and the organic film is removed by firing the transparent substrate at a temperature of 500 ° C. or less. 3. The liquid crystal display device according to 1. 14. A liquid crystal display comprising: a pair of transparent substrates opposed to each other with a liquid crystal interposed therebetween; and an organic film and an inorganic film formed on one of the transparent substrates on the liquid crystal side. A liquid crystal display device wherein the ratio of metal atoms to oxygen atoms is less than 83.3% by Auger analysis at any of the four corners in the display region of the transparent substrate after the removal. 15. A color filter, comprising: a pair of transparent substrates opposed to each other via a liquid crystal; and a color filter, a black matrix, and an overcoat film formed on one of the transparent substrates on the liquid crystal side. , 4 in the display area of the transparent substrate after removing the black matrix and the overcoat film.
At any of the corners, the ratio of metal atoms to oxygen atoms is less than 40.0% by Auger analysis. 16. A color filter comprising: a pair of transparent substrates opposed to each other via a liquid crystal; and a color filter, a black matrix, and an overcoat film formed on one of the transparent substrates on the liquid crystal side. , 4 in the display area of the transparent substrate after removing the black matrix and the overcoat film.
A liquid crystal display device in which the ratio of metal atoms to oxygen atoms is less than 38.5% by Auger analysis at any of the corners. 17. A liquid crystal display comprising: a pair of transparent substrates opposed to each other via a liquid crystal; and an organic film and an inorganic film formed on one of the transparent substrates on the liquid crystal side. A liquid crystal display device wherein the ratio of metal atoms to oxygen atoms is less than 9.2% by Auger analysis at any of the four corners in the display region of the transparent substrate after the removal. 18. The method according to claim 18, wherein the color filter, the black matrix and the overcoat film are removed by removing the transparent substrate.
The liquid crystal display device according to any one of claims 15 and 16, wherein the liquid crystal display device is fired at a temperature of 00 ° C or lower. 19. The method according to claim 14, wherein the organic film is one of a color filter and a black matrix, and the organic film is removed by firing the transparent substrate at a temperature of 500 ° C. or less. 3. The liquid crystal display device according to 1. 20. One of the transparent substrates to be configured as an envelope of a liquid crystal display device, the other of which has a transparent conductive film formed on one surface of the transparent substrate, the periphery of which is separated in a later step. In the peripheral region of the surface of the above, the ratio of metal atoms to oxygen atoms was 92.1% by Auger analysis.
A transparent substrate characterized by being less than. 21. One of the transparent substrates to be formed as an envelope of a liquid crystal display device, wherein a transparent conductive film is formed on one surface thereof, and oxygen is analyzed by Auger analysis in a display region of the other surface. The ratio of metal atoms to atoms is 3
A transparent substrate characterized by being less than 8.5%. 22. A liquid crystal display comprising: a pair of transparent substrates opposed to each other with a liquid crystal interposed therebetween; and a color filter and a black matrix formed on one of the transparent substrates on the liquid crystal side. In the display region of the transparent substrate after the black matrix is removed, when the irradiation energy is plotted on the horizontal axis and the intensity is plotted on the vertical axis as the data measured by Auger analysis, the intensity of the carbon atoms in the direction of the vertical axis indicates the metal. A liquid crystal display device having an atomic strength or higher. 23. The liquid crystal display device according to claim 22, wherein the intensity on the vertical axis is the intensity of Auger electrons. 24. One of the transparent substrates for constituting an envelope of a liquid crystal display device, wherein a plurality of the transparent substrates are arranged substantially in a vertical plane, and a surface opposite to a surface on a liquid crystal side thereof. A method for manufacturing a liquid crystal display device in which a transparent conductive material is scattered and deposited from the transparent substrate, wherein a shielding material for preventing the transparent conductive material from wrapping around when scattered is disposed between the transparent substrates arranged in parallel. A method of manufacturing a liquid crystal display device. 25. The metal atom is In, Sn, Al, C
and r, Ta, Mo, or W.
The liquid crystal display device according to any one of 16, 17, 20, 21, and 22.