JP3873601B2 - LIQUID CRYSTAL DEVICE MANUFACTURING DEVICE, ITS MANUFACTURING METHOD, LIQUID CRYSTAL SUBSTRATE, AND LIQUID CRYSTAL DEVICE - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform rubbing treatment with optimum rubbing strength. SOLUTION: A light-detecting part 102 detects surface and bottom reflected light from a substrate 112 on a placement table 100 and plate thickness detecting circuit 103 obtains information on the plate thickness of the substrate 112, based on the result of light detection and outputs the information to a computer 104. The plate thickness of the substrate 112 is calculated by the computer 104. The computer 104 controls a control circuit 106 based on the calculated plate thickness to move the placement table 100 in upper and lower directions and to control the interval between the peripheral surface of a rubbing roller 101 and an alignment layer of the substrate 112 to a specified value. The control circuit 106 controls a substrate surface direction transfer motor 108 to convey the placement table 100 to the lower side of the rubbing roller 101 and to perform rubbing treatment of the substrate 112. Thus, the rubbing treatment using optimum rubbing strength will always be performed, regardless of the fluctuation of the plate thickness of the substrate.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a manufacturing apparatus of a liquid crystal device, a manufacturing method thereof, a liquid crystal substrate, and a liquid crystal device that perform a rubbing process with an appropriate rubbing strength.
[0002]
[Prior art]
A liquid crystal device such as a liquid crystal light valve is configured by sealing liquid crystal between two substrates such as a glass substrate and a quartz substrate. In a liquid crystal light valve, switching elements such as thin film transistors (hereinafter referred to as TFTs), for example, are arranged in a matrix on one substrate, and a counter electrode is arranged on the other substrate and sealed between the two substrates. By changing the optical characteristics of the stopped liquid crystal layer according to the image signal, it is possible to display an image.
[0003]
The TFT substrate on which the TFT is disposed and the counter substrate disposed to face the TFT substrate are manufactured separately. Both substrates are bonded together with high accuracy in the panel assembling process, and then liquid crystal is sealed therein.
[0004]
In the panel assembly process, first, an alignment film is formed on the opposing surfaces of the TFT substrate and the counter substrate manufactured in each substrate process, that is, on the surface in contact with the liquid crystal layer of the counter substrate and the TFT substrate, and then the rubbing process. Is done. Next, a seal portion serving as an adhesive is formed on the edge of one substrate. The TFT substrate and the counter substrate are bonded together using a seal portion, and are cured by pressure bonding while performing alignment. A part of the seal part is provided with a notch, and the liquid crystal is sealed through the notch.
[0005]
The alignment of the liquid crystal molecules when no voltage is applied is determined by forming an alignment film and subjecting the liquid crystal to rubbing treatment. The alignment film is formed, for example, by applying polyimide with a thickness of about several tens of nanometers. By forming an alignment film on the surfaces of both substrates facing the liquid crystal layer, the liquid crystal molecules can be aligned along the substrate surface. In the rubbing process, fine grooves are formed on the surface of the alignment film, or the directionality of the polymer side chain is made uniform to form an alignment anisotropic film. The alignment film is rubbed in a certain direction. By applying, the arrangement of liquid crystal molecules can be defined.
[0006]
As a specific rubbing method, first, a substrate having a polyimide film is placed on a mounting table of a rubbing apparatus with the polyimide film facing up. Next, a rubbing roller having a rubbing cloth attached around the roller is placed in contact with the polyimide film, the rubbing roller is moved in a predetermined direction, and the polyimide film is rubbed to thereby rub the alignment film. Form.
[0007]
By the way, the rubbing strength is determined by the positional relationship between the rubbing roller and the polyimide film. The rubbing strength affects the alignment characteristics of the liquid crystal. Therefore, it is necessary to strictly define the positional relationship (relative distance) between the rubbing roller and the polyimide film (substrate). Conventionally, the positional relationship between the rubbing roller and the substrate is set to a predetermined value based on the predetermined substrate. By doing so, variations in orientation characteristics are suppressed.
[0008]
However, since the thickness varies among the substrates, when the rubbing process is performed with the positional relationship between the rubbing roller and the substrate set to a predetermined value, the rubbing strength varies between the substrates.
[0009]
For example, when comparing a thin substrate with a thick substrate, the contact length between the rubbing cloth and the alignment film is smaller in the thin substrate than in the thick substrate, so that the rubbing strength is decreased. Then, the orientation of the liquid crystal molecules becomes weak, which causes the occurrence of uneven tilt of the liquid crystal molecules and the reverse twist domain.
[0010]
On the other hand, since the rubbing strength is increased in a thick substrate, the alignment of the liquid crystal becomes too strong, which causes generation of minute foreign matters due to the shaving of the alignment film and a decrease in the tilt of the liquid crystal molecules.
[0011]
Such tilt unevenness, reverse twist, and shaving of the alignment film cause deterioration in display quality of the liquid crystal device. In particular, when a liquid crystal device is used as a light valve of a projection display device, an image is enlarged and projected on the projection display device, so that display defects due to uneven alignment of liquid crystal become significant.
[0012]
Therefore, in recent years, a feedback method has been proposed in which the substrate plate thickness is measured by a contact method using a contact pin or the like, and the rubbing condition is changed for each substrate based on the measurement result.
[0013]
[Problems to be solved by the invention]
However, a TFT array substrate, for example, does not always measure the substrate thickness accurately because an active region in which a plurality of TFTs and the like are formed on a quartz substrate is formed. Further, due to the thermal history of the substrate, shrinkage of the laminated film, etc., the substrate is warped, for example, about 100 μm, and it is difficult to accurately measure the substrate thickness. For example, when the rubbing process is performed based on the measurement result of the substrate plate thickness in a state where the warp has occurred, a desired rubbing pressure cannot be obtained, and as a result, the display quality is deteriorated.
[0014]
The present invention has been made in view of such problems, and an object of the present invention is to provide an apparatus for manufacturing a liquid crystal device, a method for manufacturing the same, a liquid crystal substrate, and a liquid crystal device capable of obtaining an optimum rubbing strength.
[0015]
[Means for Solving the Problems]
An apparatus for manufacturing a liquid crystal device according to the present invention includes a mounting table on which a substrate on which an alignment film is formed is transported and placed during transportation;
A rubbing roller for rubbing the alignment film;
A support member that, when transported and placed, supports the substrate on the mounting table via a gap provided with an air layer by a predetermined support member, and then releases the support member;
Plate thickness detection for optically detecting the substrate thickness in a predetermined region of the substrate for each substrate after the substrate is supported on the mounting table via the gap and before the support member is released. Means,
After releasing the support of the support member, suction fixing means for fixing the substrate on the mounting table by suction,
Movement control for controlling movement of at least one of the mounting table and the rubbing roller based on the detection result of the plate thickness detecting means in order to set the distance between the peripheral surface of the rubbing roller and the alignment film of the substrate to a predetermined value. Means,
The plate thickness detecting means detects the thickness of the substrate by detecting an interval between reflected light from the substrate surface and reflected light from the substrate bottom surface of the light projected onto the substrate. To do.
The method for manufacturing a liquid crystal device according to the present invention includes a procedure for supporting the substrate with a predetermined support member through an air layer in order to transport and place the substrate on which the alignment film is formed on the mounting table. ,
In a state where the substrate is supported by the support member, the thickness of the substrate in a predetermined region of the substrate is set such that the interval between the reflected light from the substrate surface and the reflected light from the substrate bottom surface of the light projected on the substrate is set. A plate thickness detection procedure to detect optically by detecting;
After the plate thickness detecting means, releasing the support of the support member and sucking and fixing the substrate on the mounting table,
In order to set the distance between the peripheral surface of the rubbing roller that rubs the alignment film and performs the rubbing process and the alignment film of the substrate to a predetermined value, the mounting table and the rubbing roller according to the detection result of the plate thickness detection procedure And a step of moving at least one of the substrate and the rubbing roller in parallel with the substrate surface for rubbing while sequentially controlling at least one of the substrate and the substrate surface.
An apparatus for manufacturing a liquid crystal device according to the present invention includes a mounting table on which a liquid crystal substrate on which an alignment film is formed is mounted, and a plate thickness detection unit that optically detects the substrate thickness in a predetermined region of the liquid crystal substrate for each substrate. In order to set the distance between the peripheral surface of the rubbing roller that rubs the alignment film and performs the rubbing process and the alignment film of the liquid crystal substrate to a predetermined value, based on the detection result of the plate thickness detection means, And a movement control means for controlling movement of at least one of the rubbing rollers.
[0016]
According to such a configuration, the liquid crystal substrate is mounted on the mounting table. The plate thickness detecting means optically detects the substrate thickness in a predetermined region of the liquid crystal substrate. The movement control means controls movement of at least one of the mounting table and the rubbing roller based on the detection result of the plate thickness detection means in order to set the distance between the peripheral surface of the rubbing roller and the alignment film of the liquid crystal substrate to a predetermined value. Since the plate thickness is detected for each substrate, the distance between the peripheral surface of the rubbing roller and the alignment film of the liquid crystal substrate is maintained at a predetermined value regardless of variations in the plate thickness for each substrate, and an optimum rubbing strength is obtained. .
[0017]
The plate thickness detection means obtains the substrate thickness by detecting an interval between the reflected light from the surface of the liquid crystal substrate and the reflected light from the bottom surface of the liquid crystal substrate of the light projected on the liquid crystal substrate. Features.
[0018]
According to such a configuration, the substrate thickness can be detected with extremely high accuracy without being affected by the warp of the liquid crystal substrate.
[0019]
Further, as the plate thickness detecting means, one that performs optical detection in a region where no element is formed on the liquid crystal substrate can be employed.
[0020]
Further, the region has transparency.
[0021]
According to such a configuration, the reliability of substrate thickness detection is high.
[0022]
Moreover, in one aspect of the apparatus for manufacturing a liquid crystal device according to the present invention, the plate thickness detection means provides a gap between the surface of the mounting table and the liquid crystal substrate placed on the mounting table. A support member for supporting the liquid crystal substrate is provided.
[0023]
According to such a configuration, it is possible to prevent the substrate thickness from being affected by the surface of the mounting table in detecting the substrate thickness.
[0024]
Further, the plate thickness detection means is characterized in that an air layer is provided in a gap between the mounting table surface and the liquid crystal substrate.
[0025]
According to such a configuration, the liquid crystal substrate is in contact with the air layer on the front surface and the bottom surface, so that sufficiently strong surface reflection light and bottom surface reflection light can be obtained, and the substrate thickness detection accuracy can be improved.
[0026]
The liquid crystal device manufacturing apparatus of the present invention further includes a rubbing roller that performs a rubbing process on the alignment film.
[0027]
According to such a configuration, the rubbing process can be performed with the optimum rubbing strength.
[0028]
The method for manufacturing a liquid crystal device according to the present invention includes: a step of supporting a liquid crystal substrate on which an alignment film is formed on a mounting table through an air layer by a predetermined support member; and a substrate thickness in a predetermined region of the liquid crystal substrate. A plate thickness detection procedure for optical detection, a procedure for releasing the support of the support member and sucking and fixing the liquid crystal substrate on the mounting table, and a peripheral surface of a rubbing roller for rubbing the alignment film In order to set the distance between the liquid crystal substrate and the alignment film of the liquid crystal substrate to a predetermined value, while controlling the movement of at least one of the mounting table and the rubbing roller perpendicularly to the liquid crystal substrate surface based on the detection result of the plate thickness detection procedure And a procedure for moving at least one of the liquid crystal substrate and the rubbing roller in parallel with the liquid crystal substrate surface for rubbing treatment.
[0029]
According to such a configuration, first, the liquid crystal substrate is supported on the mounting table by the predetermined support member via the air layer. The substrate thickness is optically detected in a predetermined region of the liquid crystal substrate. The front and bottom surfaces of the liquid crystal substrate are in contact with the air layer, and the optical detection accuracy of the substrate thickness is high. Next, the liquid crystal substrate is sucked and fixed on the mounting table. The distance between the peripheral surface of the rubbing roller and the alignment film of the liquid crystal substrate is maintained at a predetermined value by controlling the movement of at least one of the mounting table and the rubbing roller perpendicularly to the liquid crystal substrate surface based on the detected substrate thickness. In this state, at least one of the liquid crystal substrate and the rubbing roller is moved in parallel with the liquid crystal substrate surface to perform the rubbing process. Thereby, the rubbing process with the optimum rubbing strength can be performed.
[0030]
The plate thickness detection procedure includes a procedure of projecting light onto the liquid crystal substrate, and a procedure of detecting an interval between reflected light from the surface of the liquid crystal substrate and reflected light from the bottom surface of the liquid crystal substrate. And a procedure for calculating a substrate thickness of the liquid crystal substrate based on the interval.
[0031]
According to such a configuration, it is possible to measure the substrate thickness with extremely high accuracy without being affected by the warp of the liquid crystal substrate.
[0032]
In the plate thickness detection procedure of the present invention, the substrate thickness is detected for each liquid crystal substrate.
[0033]
According to such a configuration, the optimum rubbing strength can always be obtained regardless of variations in the substrate thickness of the liquid crystal substrate.
[0034]
A liquid crystal substrate according to the present invention is rubbed by the method for manufacturing a liquid crystal device according to claim 8.
[0035]
According to such a configuration, an optimum rubbing strength substrate can be obtained.
[0036]
A liquid crystal device according to the present invention uses the liquid crystal substrate according to claim 11.
[0037]
According to such a configuration, stable display characteristics can be obtained.
[0038]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing an apparatus for manufacturing a liquid crystal device according to a first embodiment of the present invention. FIG. 2 is a schematic diagram showing a specific configuration of the light detection unit 102 and the plate thickness detection circuit 103 in FIG. FIG. 3 is an equivalent circuit diagram of various elements and wirings in a plurality of pixels constituting the pixel region of the liquid crystal device. FIG. 4 is a plan view of an element substrate such as a TFT substrate as viewed from the side of the counter substrate together with the components formed thereon, and FIG. 5 is an assembly process in which the liquid crystal is sealed by bonding the element substrate and the counter substrate together. FIG. 5 is a cross-sectional view showing the liquid crystal device after being cut at the position of the line HH ′ in FIG. 4. FIG. 6 is a cross-sectional view showing the liquid crystal device in detail. FIG. 7 is a flowchart showing the panel assembly process.
[0039]
First, the structure of the liquid crystal panel will be described with reference to FIGS.
[0040]
As shown in FIGS. 4 and 5, the liquid crystal panel is configured by enclosing a liquid crystal 50 between an element substrate 10 such as a TFT substrate and a counter substrate 20. On the element substrate 10, pixel electrodes and the like constituting pixels are arranged in a matrix. FIG. 3 shows an equivalent circuit of elements on the element substrate 10 constituting the pixel.
[0041]
As shown in FIG. 3, in the pixel region, a plurality of scanning lines 3a and a plurality of data lines 6a are wired so as to cross each other, and a pixel electrode is formed in a region partitioned by the scanning lines 3a and the data lines 6a. 9a are arranged in a matrix. A TFT 30 is provided corresponding to each intersection of the scanning line 3 a and the data line 6 a, and the pixel electrode 9 a is connected to the TFT 30.
[0042]
The TFT 30 is turned on by the ON signal of the scanning line 3a, whereby the image signal supplied to the data line 6a is supplied to the pixel electrode 9a. A voltage between the pixel electrode 9 a and the counter electrode 21 provided on the counter substrate 20 is applied to the liquid crystal 50. In addition, a storage capacitor 70 is provided in parallel with the pixel electrode 9a, and the storage capacitor 70 holds the voltage of the pixel electrode 9a for a time that is, for example, three digits longer than the time when the source voltage is applied. The storage capacitor 70 improves retention characteristics and enables image display with a high contrast ratio.
[0043]
FIG. 6 is a schematic cross-sectional view of a liquid crystal panel focusing on one pixel.
[0044]
An element substrate 10 such as glass or quartz is provided with a TFT 30 having an LDD structure. The TFT 30 includes a scanning line 3a that forms a gate electrode through an insulating film 2 on a semiconductor layer in which a channel region 1a, a source region 1d, and a drain region 1e are formed. A data line 6 a is stacked on the TFT 30 via the first interlayer insulating film 4, and the data line 6 a is electrically connected to the source region 1 d via the contact hole 5. A pixel electrode 9 a is stacked on the data line 6 a via a second interlayer insulating film 7, and the pixel electrode 9 a is electrically connected to the drain region 1 e via a contact hole 8.
[0045]
When the ON signal is supplied to the scanning line 3a (gate electrode), the channel region 1a becomes conductive, the source region 1d and the drain region 1e are connected, and the image signal supplied to the data line 6a becomes the pixel electrode. 9a.
[0046]
A storage capacitor electrode 1f extending from the drain region 1e is formed in the semiconductor layer. The storage capacitor electrode 1f is disposed so that the capacitor line 3b faces the insulating film 2 as a dielectric film, thereby forming a storage capacitor 70. An alignment film 16 made of a polyimide polymer resin is laminated on the pixel electrode 9a, and is rubbed in a predetermined direction by the apparatus shown in FIG.
[0047]
On the other hand, the counter substrate 20 is provided with a first light-shielding film 23 in a region facing the data line 6a, scanning line 3a, and TFT 30 formation region of the TFT array substrate, that is, in a non-display region of each pixel. The first light shielding film 23 prevents incident light from the counter substrate 20 side from entering the channel region 1 a, the source region 1 d, and the drain region 1 e of the TFT 30. A counter electrode (common electrode) 21 is formed over the entire surface of the substrate 20 on the first light shielding film 23. An alignment film 22 made of a polyimide-based polymer resin is laminated on the counter electrode 21, and is rubbed in a predetermined direction by an apparatus similar to that shown in FIG.
[0048]
A liquid crystal 50 is sealed between the element substrate 10 and the counter substrate 20. Thereby, the TFT 30 writes the image signal supplied from the data line 6a to the layer electrode 9a at a predetermined timing. Depending on the potential difference between the written pixel electrode 9a and the counter electrode 21, the orientation and order of the molecular assembly of the liquid crystal 50 change, and light is modulated to enable gradation display.
[0049]
As shown in FIGS. 4 and 5, the counter substrate 20 is provided with a second light shielding film 42 as a frame for partitioning the display area. The second light shielding film 42 is formed of, for example, the same or different light shielding material as the first light shielding film 23.
[0050]
A sealing material 41 that encloses liquid crystal in a region outside the second light shielding film 42 is formed between the element substrate 10 and the counter substrate 20. The sealing material 41 is disposed so as to substantially match the contour shape of the counter substrate 20 and fixes the element substrate 10 and the counter substrate 20 to each other. The sealing material 41 is missing at a part of the center of one side of the element substrate 10 and forms a liquid crystal injection port 78 for injecting the liquid crystal 50 into the gap between the bonded element substrate 10 and the counter substrate 20. . After the liquid crystal is injected from the liquid crystal injection port 78, it is sealed with a sealing material 79.
[0051]
A data line driving circuit 61 and a mounting terminal 62 are provided along one side of the element substrate 10 in a region outside the sealing material 41 of the element substrate 10, and scanning lines are provided along two sides adjacent to the one side. A drive circuit 63 is provided. On the remaining side of the element substrate 10, a plurality of wirings 64 are provided for connecting between the scanning line driving circuits 63 provided on both sides of the screen display area. In addition, a conductive material 65 for electrically connecting the element substrate 10 and the counter substrate 20 is provided in at least one corner of the counter substrate 20.
[0052]
Next, the panel assembly process will be described with reference to FIG. The element substrate 10 (TFT substrate) and the counter substrate 20 are manufactured separately. In the next steps S2 and S7, polyimide to be the alignment films 16 and 22 is applied to the TFT substrate and the counter substrate 20 prepared in steps S1 and S6, respectively. Next, in steps S3 and S8, the alignment film 16 on the surface of the element substrate 10 and the alignment film 22 on the surface of the counter substrate 20 are rubbed.
[0053]
Next, a cleaning process is performed in steps S4 and S9. This cleaning process is for removing dust generated by the rubbing process.
[0054]
When the cleaning process is completed, a sealing material 41 and a conductive material 65 (see FIG. 3) are formed in step S5. Next, in step S10, the element substrate 10 and the counter substrate 20 are bonded together, and in step S11, pressure bonding is performed while alignment is performed, and the sealing material 41 is cured. Finally, in step S12, liquid crystal is sealed from a notch provided in a part of the sealing material 41, and the notch is closed to seal the liquid crystal.
[0055]
In FIG. 1, a substrate 112 which is a liquid crystal substrate on which an alignment film is formed is placed on a mounting table 100 with the alignment film facing upward. The mounting table 100 can be conveyed in one direction parallel to the surface of the mounting table 100 by a substrate surface direction moving motor 108. The mounting table 100 can be moved up and down in a direction perpendicular to the surface of the mounting table 100 by a vertical movement motor 107.
[0056]
A rubbing roller 101 is disposed above the horizontal conveyance path of the mounting table 100. The rubbing roller 101 is configured by attaching a rubbing cloth (not shown) on the circumference of a cylindrical roller, and is rotatable in the circumferential direction. The rubbing cloth attached to the rubbing roller 101 sequentially rubs the alignment film of the substrate 112 on the mounting table 100 to perform the rubbing process by conveying the mounting table 100 to the rubbing roller 101 side while rotating the rubbing roller 101. It is like that.
[0057]
The light detection unit 102 detects light from the substrate 112 mounted on the mounting table 100 and outputs a detection result to the plate thickness detection circuit 103. The plate thickness detection circuit 103 detects information related to the plate thickness of the substrate 112 from the light detection result and outputs the detection result to the computer 104.
[0058]
FIG. 2 shows a specific configuration of the light detection unit 102 and the plate thickness detection circuit 103 in FIG. The stage 110 is attached above the mounting table 100. Stage pins 111 are implanted in the stage 110, and the substrate 112 is placed on the stage pins 111. The stage pin 111 can be displaced upward and downward. When the stage pin 111 is displaced downward (stage pin down), the upper end is located below the upper surface of the stage 110 and when it is displaced upward (stage pin up). The upper end is positioned above the upper surface of the stage 110.
[0059]
That is, the stage pin 111 supports the substrate 112 at the upper end in the stage pin-up state, and provides a gap between the bottom surface of the substrate 112 and the upper surface of the stage 110. The substrate 112 is placed on the upper surface of the stage 110 so as to be positioned below the upper surface. The stage 110 can suck and fix the substrate 112 in a stage pin down state. In the stage pin-up state, the bottom surface of the substrate 112 is in contact with air having a large refractive index difference from the substrate 112.
[0060]
A projection beam emitting unit (not shown) is fixed above the stage 110, and the projection beam emitting unit can emit the projection beam obliquely upward from the substrate 112. The projection beam is reflected by the substrate 112. A light receiving lens 113 is provided on the optical path of the reflected light of the projection beam from the substrate 112.
[0061]
The light receiving lens 113 is, for example, a convex lens, and refracts and transmits the reflected light. A light receiving surface of the two-dimensional CCD 114 is disposed on the optical path of the light passing through the light receiving lens 113. The two-dimensional CCD 114 outputs to the computer 104 an output corresponding to the light amount distribution (light reception distribution) of light incident on the light receiving surface.
[0062]
The computer 104 calculates the thickness of the substrate 112 based on the output corresponding to the light reception distribution of the two-dimensional CCD 114. That is, the projected beam projected onto the substrate 112 is reflected on the surface of the substrate 112 and passes through the surface of the substrate 112 due to the difference in refractive index between the substrate 112 and the air around the substrate 112, and the bottom surface of the substrate 112. Reflect on. 2 indicate the reflected light on the surface of the substrate 112 (hereinafter referred to as “surface reflected light”), and the broken arrow indicates the reflected light on the bottom surface of the substrate 112 (hereinafter referred to as “bottom reflected light”).
[0063]
The front surface reflected light and the bottom surface reflected light are incident on the light receiving lens 113 at intervals corresponding to the thickness of the substrate 112. The light receiving lens 113 increases the interval between the surface reflected light and the bottom surface reflected light and makes it incident on the light receiving surface of the two-dimensional CCD 114. Of all the reflected light from the substrate 112, the reflected light amount of the surface reflected light and the bottom surface reflected light is larger than the reflected light amount of the other part, and the reflected light amount of the surface reflected light is larger than the reflected light amount of the bottom surface reflected light. .
[0064]
Accordingly, the two-dimensional CCD 114 obtains a light reception distribution that shows peaks at the incident position of the surface reflected light and the incident position of the bottom surface reflected light. The maximum peak position of the received light distribution of the two-dimensional CCD 114 indicates the position of the surface of the substrate 112, and the second peak position indicates the position of the bottom surface of the substrate 112.
[0065]
The position detection circuit 105 detects the position of the mounting table 100 and outputs the position detection result to the computer 104. The computer 104 grasps the detection area of the light reception distribution of the two-dimensional CCD 114 from the position detection result, and calculates the thickness of the substrate 112 in the detection area based on the output of the two-dimensional CCD 114. The computer 104 outputs vertical position control information for controlling the vertical position of the mounting table 100 to the control circuit 106 based on the calculated plate thickness. Further, the computer 104 outputs to the control circuit 106 an upper horizontal position control for controlling the movement of the substrate 112 in the surface direction.
[0066]
The control circuit 106 drives and controls the substrate surface direction moving motor 108 based on the horizontal position control information from the computer 104, moves the mounting table 100, and conveys the substrate 112 to the rubbing roller 101 side. Yes. Further, the control circuit 106 drives and controls the vertical movement motor 107 based on the vertical position control information to displace the mounting table 100 in the vertical direction, so that the peripheral surface of the rubbing roller 101 and the alignment film of the substrate 112 are aligned. The interval can be maintained at a predetermined optimum value regardless of the thickness of the substrate 112.
[0067]
The detection of the substrate plate thickness and the position control are performed for each substrate.
[0068]
Next, the operation of the embodiment configured as described above will be described with reference to FIGS. FIG. 8 is a flowchart specifically showing the rubbing process in steps S3 and S8 in FIG. 7, and FIG. 9 is an explanatory diagram for explaining the measurement of the plate thickness.
[0069]
A rubbing process for the substrate 112 on which the element substrate 10 is formed will be described. In step S2 in FIG. 7, polyimide to be the alignment film 16 is applied. Next, the rubbing process of step S3 is performed.
[0070]
In step S3, as shown in FIG. 8, first, the stage pin-up state is set (step S21). Thereby, the tip of the stage pin 111 is located above the surface of the stage 111. In this state, the substrate 112 is transferred to the stage 111 side by a transfer device (not shown) and placed on the stage pin 111. FIG. 2 shows this state, and not only the surface of the substrate 112 but also the bottom surface is in contact with air. As a result, not only the surface of the substrate 112 but also the bottom surface of the substrate 112 has a large change in refractive index, and the projected beam is reflected. Further, the influence of reflected light from the stage 110 can be avoided.
[0071]
Next, in step S23, the displacement in the detection region is measured. That is, a projection beam is projected onto the surface of the substrate 112 from a projection beam emitting unit (not shown). FIG. 9 shows the projection of the projection beam in three dimensions. The projected beam is reflected on the surface and bottom surface of the substrate 112, and the surface reflected light and bottom surface reflected light are reflected above the surface of the substrate 112 at intervals corresponding to the thickness of the substrate 112.
[0072]
The front surface reflected light and the bottom surface reflected light pass through the light receiving lens 113 and enter the light receiving surface of the two-dimensional CCD 114. The light receiving lens 113 increases the distance between the surface reflected light and the bottom reflected light and makes it incident on the light receiving surface of the two-dimensional CCD 114.
[0073]
In step S24, the two-dimensional CCD 114 outputs an output corresponding to the received light distribution to the computer 104. The computer 104 calculates the plate thickness in the detection region from the output corresponding to the received light distribution. When the calculation of the plate thickness is completed, the computer 104 controls a drive unit (not shown) to bring the stage pin 111 into a stage pin down state (step S25). As the stage pins 111 are lowered, the bottom surface of the substrate 112 comes into contact with the stage 111. The stage 111 sucks and fixes the substrate 112 in step S26.
[0074]
The computer 104 outputs vertical position control information based on the calculated plate thickness to the control circuit 106. In step S27, the control circuit 106 drives the vertical movement motor 107 to move the stage 111 up and down, thereby setting the interval between the peripheral surface of the rubbing roller 101 and the alignment film 16 of the substrate 112 to a specified value.
[0075]
Next, in step S28, the control circuit 106 drives and controls the substrate surface direction moving motor 108 based on the horizontal position control information from the computer 104, and moves the mounting table 100 to the rubbing roller 101 side at a predetermined speed. As a result, the substrate 112 is conveyed to the lower side of the rubbing roller 101. The alignment film 16 is rubbed with a rubbing cloth by the rotation of the rubbing roller 101 on the substrate 112. Thereby, rubbing is performed. The distance between the peripheral surface of the rubbing roller 101 and the alignment film of the substrate 112 is maintained at a predetermined value regardless of the thickness of the substrate 112, and the rubbing strength is maintained at a predetermined value.
[0076]
When the rubbing process is completed, the substrate 112 is unloaded by a transfer device (not shown) (step S29).
[0077]
Thus, in this embodiment, for each substrate to be rubbed, a projection beam is projected onto the substrate surface, the thickness of the substrate is measured by the reflected light, and the rubbing roller is measured according to the measurement result. The distance between the peripheral surface of the substrate and the alignment film of the substrate is maintained at a specified value, and the rubbing process can always be performed with the optimum rubbing strength regardless of variations in the thickness of the substrate. Thereby, the display quality of the liquid crystal device can be improved. Further, since the plate thickness is detected by a non-contact method using an optical technique, it is possible to prevent the substrate surface from being damaged. Moreover, since the plate thickness is detected by an optical method using a light receiving lens and a two-dimensional CCD, the detection accuracy is extremely high.
[0078]
In this embodiment, the mounting table is moved up and down to control the distance between the peripheral surface of the rubbing roller and the alignment film of the substrate. However, the rubbing roller may be moved up and down. it is obvious. Further, although the mounting table 100 is moved in the horizontal direction for the rubbing process, the rubbing roller 101 side may be moved.
[0079]
【The invention's effect】
As described above, according to the present invention, there is an effect that an optimum rubbing strength can be obtained.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a method for bonding a liquid crystal device according to a first embodiment of the present invention.
2 is a schematic diagram showing a specific configuration of a light detection unit 102 and a plate thickness detection circuit 103 in FIG.
FIG. 3 is an equivalent circuit diagram of various elements and wirings in a plurality of pixels constituting a pixel region of the liquid crystal device.
FIG. 4 is a plan view of an element substrate such as a TFT substrate as viewed from the counter substrate side together with each component formed thereon.
FIG. 5 is a cross-sectional view showing the liquid crystal device after being assembled at the end of the assembly process in which the element substrate and the counter substrate are bonded to each other to enclose the liquid crystal, cut along the line HH ′ in FIG. 4;
FIG. 6 is a cross-sectional view illustrating a liquid crystal device in detail.
FIG. 7 is a flowchart showing a panel assembly process.
FIG. 8 is a flowchart for explaining the operation of the embodiment;
FIG. 9 is an explanatory diagram for explaining the measurement of the plate thickness.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 100 ... Mounting stage 101 ... Rubbing roller 102 ... Light detection part 103 ... Thickness detection circuit 104 ... Computer 106 ... Control circuit 107 ... Vertical movement motor 108 ... Substrate surface direction movement motor

Claims (7)

A mounting table on which the substrate on which the alignment film is formed is transported and placed during transportation;
A rubbing roller for rubbing the alignment film;
A support member that, when transported and placed, supports the substrate on the mounting table via a gap provided with an air layer by a predetermined support member, and then releases the support member;
Plate thickness detection for optically detecting the substrate thickness in a predetermined region of the substrate for each substrate after the substrate is supported on the mounting table via the gap and before the support member is released. Means,
After releasing the support of the support member, suction fixing means for fixing the substrate on the mounting table by suction,
Movement control for controlling movement of at least one of the mounting table and the rubbing roller based on the detection result of the plate thickness detecting means in order to set the distance between the peripheral surface of the rubbing roller and the alignment film of the substrate to a predetermined value. Means,
The plate thickness detecting means detects the thickness of the substrate by detecting an interval between reflected light from the substrate surface and reflected light from the substrate bottom surface of the light projected onto the substrate. Manufacturing equipment for liquid crystal devices.   The apparatus for manufacturing a liquid crystal device according to claim 1, wherein the plate thickness detection unit performs optical detection in a region where no element is formed on the substrate.   The liquid crystal device manufacturing apparatus according to claim 2, wherein the region has transparency. In order to transport and place the substrate on which the alignment film is formed on the mounting table, a procedure for supporting the substrate via an air layer by a predetermined support member;
In a state where the substrate is supported by the support member, the thickness of the substrate in a predetermined region of the substrate is set such that the interval between the reflected light from the substrate surface and the reflected light from the substrate bottom surface of the light projected on the substrate is set. A plate thickness detection procedure to detect optically by detecting;
After the plate thickness detecting means, releasing the support of the support member and sucking and fixing the substrate on the mounting table,
In order to set the distance between the peripheral surface of the rubbing roller that rubs the alignment film and performs the rubbing process and the alignment film of the substrate to a predetermined value, the mounting table and the rubbing roller according to the detection result of the plate thickness detection procedure And a step of moving at least one of the substrate and the rubbing roller in parallel with the substrate surface for rubbing while sequentially controlling at least one of the substrate and the substrate surface. Production method.   The method of manufacturing a liquid crystal device according to claim 4, wherein the plate thickness detection procedure detects a substrate thickness for each substrate.   A liquid crystal substrate, which is rubbed by the method for manufacturing a liquid crystal device according to claim 4.   A liquid crystal device using the liquid crystal substrate according to claim 6.

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