JP4098449B2 - Method for rubbing substrate for liquid crystal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of rubbing for manufacturing a liquid crystal device with excellent display characteristics and to provide a rubbing device. SOLUTION: The warpage of a substrate on which an alignment layer is formed is dissolved by suctionally fixing it to a stage and the thickness of the substrate is measured in the state with no warpage. Rubbing treatment is carried out under the rubbing condition set up on the basis of the result of the measurement. Thereby, the rubbing treatment under a desired rubbing pressure can be carried out and the liquid crystal device with the excellent display characteristics can be obtained.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to the technical field of liquid crystal devices, and particularly to the technical field of rubbing treatment of alignment films.
[0002]
[Prior art]
The liquid crystal device is configured by sandwiching a liquid crystal layer between a counter substrate and a TFT array substrate, and performs display by applying a voltage to the liquid crystal layer to change the optical characteristics of the liquid crystal molecules. Counter substrate and TFT array substrate On the liquid crystal layer An alignment film is disposed on the contact surface, and the alignment of the liquid crystal molecules when no voltage is applied is determined by the alignment film. The alignment film is formed by performing a rubbing method in which the surface of an organic film such as polyimide is rubbed in a predetermined direction with a cloth or the like.
[0003]
A specific rubbing method is as follows. First, a substrate having a polyimide film is placed on the mounting table of the rubbing apparatus with the polyimide film facing up. Next, the rubbing roller with the rubbing cloth attached around the roller was placed in contact with the polyimide film, the rubbing roller or the mounting table was moved in a predetermined direction, and the rubbing treatment was performed by rubbing the polyimide film. An alignment film is formed. In such a rubbing apparatus, the positional relationship between the rubbing roller and the substrate is set to a predetermined value on the basis of the thickness of one substrate, and the other substrate is rubbed with this value fixed at all times. We were processing. In addition, the thickness of the substrate is measured in advance before the substrate is placed on the mounting table.
[0004]
[Problems to be solved by the invention]
However, when measuring the thickness of the substrate, for example, the TFT array substrate has an active region in which a plurality of TFTs are arranged on a quartz substrate, the thermal history of the substrate, the contraction of the laminated film, etc. For this reason, a warp of, for example, 100 μm occurred on the substrate, and it was difficult to accurately measure the substrate thickness. For example, if the rubbing process is performed based on the measurement result of the substrate thickness in a state where the warp has occurred, a desired rubbing pressure cannot be obtained, resulting in a liquid crystal device having a significantly deteriorated display quality. It was. Further, since the thickness differs between 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. For example, when a thin substrate and a thick substrate are compared, 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. For this reason, the orientation of the liquid crystal molecules becomes weak, which causes the occurrence of uneven tilt of the liquid crystal molecules and reverse twist domains. On the other hand, since the rubbing strength increases 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 tilt of the liquid crystal molecules. When TFTs are used as liquid crystal drive devices and polarity inversion drive is performed between pixels or lines, disclination occurs due to the generation of a lateral electric field. Such uneven tilt, reverse twist, and disclination significantly deteriorate the display quality of the liquid crystal device. In particular, when such a liquid crystal device is used as a light valve of a projection type display device, the projection type display device enlarges and projects, so that the uneven alignment of the liquid crystal has become a fatal display defect.
[0005]
Thus, in the conventional rubbing method, a constant rubbing pressure could not be obtained due to the warpage of the substrate for the liquid crystal device and the thickness variation between the substrates, so a liquid crystal device with high display quality could not be obtained, and the production efficiency There was a problem of being bad.
[0006]
The present invention has been made to solve such problems, and a rubbing device capable of obtaining a liquid crystal device with high display quality, a rubbing method, a substrate for a liquid crystal device, and a liquid crystal device manufactured thereby. The purpose is to provide.
[0007]
[Means for Solving the Problems]
In order to solve such a problem, the present invention employs the following configuration.
[0008]
In the rubbing apparatus of the present invention, a substrate having an alignment film formed on one surface is in contact with the mounting table on which the alignment film is attracted and fixed, and from one end of the substrate to the other end. A rubbing roller for rubbing the alignment film by relatively moving, a substrate thickness measuring mechanism for measuring the thickness of the adsorption-fixed substrate,
And a moving mechanism for moving the rubbing roller or the mounting table based on a measurement result by the substrate thickness measuring mechanism.
In the rubbing apparatus of the present invention, the substrate having the alignment film formed on one surface thereof is adsorbed and fixed at a higher adsorbing pressure in the peripheral portion than in the central portion of the substrate with the alignment film facing up. A mounting table having suction holes arranged in a dense state in the region corresponding to the peripheral portion of the substrate and a sparse state distribution in the region corresponding to the central portion, and one end portion to the other end portion of the substrate in contact with the substrate By measuring the position in the vertical direction of the surface of the substrate with a rubbing roller for rubbing the alignment film by relatively moving toward the substrate, and the position of the mounting table as a reference, A substrate thickness measuring mechanism for measuring the thickness of the substrate fixed by suction; and a moving mechanism for moving the rubbing roller or the mounting table based on a measurement result by the substrate thickness measuring mechanism. To.
The method for rubbing a substrate for a liquid crystal device according to the present invention corresponds to a dense state in a region corresponding to the peripheral portion of the substrate for a liquid crystal device with the alignment film facing upward, and a center portion corresponding to the liquid crystal device substrate having an alignment film. In the region to be placed on a mounting table having suction holes arranged in a sparse distribution, and to suck and fix the liquid crystal device substrate to the mounting table by suction from the suction holes; Measuring the thickness of the liquid crystal device substrate in an adsorbed and fixed state by measuring the position of the surface of the liquid crystal device substrate in the vertical direction with a sensor on the basis of the position of the mounting table; Setting a rubbing condition based on the measurement result of the thickness of the substrate for the liquid crystal device, and rubbing the alignment film,
The liquid crystal device substrate is characterized in that the peripheral portion of the substrate for the liquid crystal device is adsorbed and fixed at a higher adsorbing pressure than the central portion.
[0009]
According to such a configuration of the present invention, the warpage of the substrate can be eliminated by attracting and fixing the substrate to the mounting table. By measuring the thickness of the substrate under such a state in which the substrate is not warped, it is possible to accurately detect the thickness of the substrate. In the present invention, since the rubbing conditions are set based on the measurement result, the rubbing process can be performed at a desired rubbing pressure.
[0010]
In the rubbing apparatus of the present invention, a substrate having an alignment film formed on one surface is in contact with the mounting table on which the alignment film is attracted and fixed, and from one end of the substrate to the other end. A rubbing roller for rubbing the alignment film by relatively moving, a rotational torque detection mechanism for detecting a rotational torque value of the rubbing roller on the suction-fixed substrate, and detection by the rotational torque detection mechanism And a moving mechanism for moving the rubbing roller or the mounting table based on the result.
[0011]
According to such a configuration of the present invention, by managing the rotational torque of the rubbing roller corresponding to the rubbing pressure within a desired range, the fluctuation due to the thickness variation between the substrates is eliminated, and the rubbing process is performed at the desired rubbing pressure. It has the effect that it can be done.
[0012]
In the mounting table, the suction holes for sucking and fixing the substrate are arranged in a dense state in a region corresponding to the peripheral portion of the substrate and in a sparse state distribution in a region corresponding to the central portion. And By adopting such a configuration, it is possible to efficiently eliminate the warping of the substrate, particularly when the substrate peripheral portion warps upward when the substrate is placed on the mounting table, and the substrate is kept in a flat state. It has the effect that it can be adsorbed and fixed to the mounting table.
[0013]
Further, the substrate is characterized in that the peripheral portion is adsorbed and fixed at a higher adsorbing pressure than the central portion of the substrate. By adopting such a configuration, it is possible to efficiently eliminate the warping of the substrate, particularly when the substrate peripheral portion warps upward when the substrate is placed on the mounting table, and the substrate is kept in a flat state. It has the effect that it can be adsorbed and fixed to the mounting table.
[0014]
The method for rubbing a substrate for a liquid crystal device according to the present invention includes: (a) a step of placing the substrate for a liquid crystal device having an alignment film on a mounting table having an adsorption hole with the alignment film facing up; and (b) the liquid crystal Sucking and fixing the device substrate to the mounting table by sucking from the suction hole, (c) measuring the thickness of the liquid crystal device substrate in the sucked and fixed state, and (d) the liquid crystal A rubbing condition is set based on a measurement result of the thickness of the device substrate, and the alignment film is rubbed.
[0015]
According to such a configuration of the present invention, the substrate warp is eliminated by adsorbing and fixing the substrate for the liquid crystal device to the mounting table, and the thickness of the substrate is measured in a state without such a substrate warp. Thus, the accurate substrate thickness can be measured. In the present invention, since the rubbing conditions are set by adjusting the position of the rubbing roll and the substrate based on the measurement result, the rubbing process can be performed with a desired rubbing pressure. Thereby, a liquid crystal device with high display quality can be obtained. Here, the rubbing conditions refer to conditions that determine the distance between the stage on which the substrate is placed during rubbing and the rubbing roller, the moving speed of the rubbing roller during rubbing, and the rubbing pressure during rubbing. Note that the mounting table on which the substrate is mounted when measuring the substrate thickness and the mounting table on which the substrate is mounted when the rubbing process is performed may be provided separately or in common.
[0016]
The method for rubbing a substrate for a liquid crystal device according to the present invention comprises: (a) a step of placing a substrate for a liquid crystal device having an alignment film on a mounting table having an adsorption hole with the alignment film facing upward; (C) a rotational torque value of a rubbing roller disposed in contact with the liquid crystal device substrate in the suction-fixed state by sucking and fixing the liquid crystal device substrate to the mounting table by sucking from the hole; A step of controlling a distance between the liquid crystal device substrate and the rubbing roller so as to be within a predetermined range; and (d) rubbing the alignment film in a state where the rotational torque value is set within a predetermined range. And a process.
[0017]
According to such a configuration of the present invention, the warpage of the substrate is eliminated by adsorbing and fixing the substrate for the liquid crystal device to the mounting table, and the rotational torque value of the rubbing roller is measured under such a state where the substrate is not warped. As a result, an accurate rotational torque value can be measured. In the present invention, since the rubbing conditions are set by adjusting the position of the rubbing roll and the substrate based on the measurement result, the rubbing process can be performed with a desired rubbing pressure. Thereby, a liquid crystal device with high display quality can be obtained. Here, the rubbing conditions refer to conditions that determine the distance between the stage on which the substrate is placed during rubbing and the rubbing roller, the moving speed of the rubbing roller during rubbing, and the rubbing pressure during rubbing. Note that the mounting table on which the substrate is mounted when measuring the substrate thickness and the mounting table on which the substrate is mounted when the rubbing process is performed may be provided separately or in common.
[0018]
Further, the liquid crystal device substrate includes an active region and a detection region in which the thickness of the liquid crystal device substrate is measured or the rotational torque value is detected. According to such a configuration, the measurement of the thickness of the substrate or the detection of the rotational torque value is performed in the detection region, so that no trouble due to the measurement occurs in the active region including the display unit. Further, since the positional relationship between the rubbing roller and the substrate is adjusted based on the measurement result, the active region including the display unit can be rubbed with a certain strength.
[0019]
In addition, the active region includes a display pixel region and a peripheral drive circuit region that controls display of the display pixel region. According to such a configuration, it can also be applied to a drive circuit integrated liquid crystal device.
[0020]
The detection area is formed at an end of the liquid crystal device substrate. According to such a configuration, since the detection region is located at one end of the substrate, the rubbing roller moves on the alignment film toward the other end by detecting the rotational torque value in such a region. In the flow of operation, the rotational torque value detection step, the rubbing roller and substrate position adjustment step, and the rubbing treatment step can be performed, so that the rubbing treatment can be performed efficiently and with an appropriate rubbing strength. .
[0021]
Further, the steps (a) to (d) are performed for different substrates for liquid crystal devices. Thereby, a rubbing process with a constant rubbing pressure strength can be performed between different substrates, and the product quality of the substrate for the liquid crystal device, which is the substrate on which the alignment film is formed, is stabilized. For example, even when a plurality of substrates having thickness variations are processed, each substrate can be rubbed with a constant rotational torque value, that is, with a constant rubbing pressure. As a result, there can be obtained a liquid crystal display substrate having no variation in rubbing strength between the substrates and having stable product characteristics, and a liquid crystal device using the substrate.
[0022]
The substrate for a liquid crystal device of the present invention is manufactured using the above-described rubbing method for a substrate for a liquid crystal device. According to such a configuration, there is an effect that it is possible to stably obtain a substrate for a liquid crystal device that is always subjected to appropriate rubbing treatment.
[0023]
A liquid crystal device of the present invention includes the above-described substrate for a liquid crystal device. According to such a configuration, a liquid crystal device having good and stable display quality can be obtained.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0025]
First, the structure of a liquid crystal device in which a substrate that has been rubbed using the rubbing method of the present invention is incorporated will be briefly described with reference to FIGS. FIG. 6 shows a substrate for a liquid crystal device according to the present invention, and is a perspective view of the substrate for a liquid crystal device during a rubbing process. The substrate for the liquid crystal device after the rubbing process may be partially cut off as necessary when the liquid crystal device is assembled. FIG. 7 is an equivalent circuit of various elements, wirings, and the like in a plurality of pixels formed in a matrix constituting the display pixel region of the liquid crystal device when a TFT array substrate is used as the substrate for the liquid crystal device. FIG. 8 is a longitudinal sectional view in the display area of the TFT array substrate on which data lines, scanning lines, pixel electrodes, light shielding films and the like are formed. In each drawing, the scale is appropriately set for each layer and each member so that each layer and each member can be recognized on the drawing.
[0026]
As shown in FIG. 6, the substrate 10 for a liquid crystal device has an active region 100 that forms the liquid crystal device, and a detection region 101 that measures the thickness of the substrate.
[0027]
As shown in FIG. 8, the liquid crystal device 31 includes a TFT array substrate 10 as a substrate for a liquid crystal device, and a counter substrate 20 disposed to face the TFT array substrate 10, and a liquid crystal layer 50 is sandwiched between the two substrates. ing. The TFT array substrate 10 and the counter substrate 20 have alignment films 16 and 22 on the side in contact with the liquid crystal layer 50, respectively. The alignment films 16 and 22 are rubbed in directions intersecting with each other, and the liquid crystal layer 50 is brought into a predetermined alignment state by the alignment films 16 and 22 in a state where an electric field from the pixel electrode 9a is not applied. take.
[0028]
As shown in FIG. 7, the active region 100 forming the liquid crystal device of the liquid crystal device substrate 10 includes a display pixel region and peripheral drive circuit regions 104 and 105 for controlling display of the display pixel region. In the display pixel region, a plurality of scanning lines 3 and a plurality of data lines 6 that intersect with each other are disposed, and a pixel electrode 9a is disposed at each intersection, and a thin film transistor (hereinafter referred to as a thin film transistor) for controlling the pixel electrode 9a. TFT) 30 is disposed, and a capacitor line 3 b is disposed substantially parallel to the scanning line 3. In the peripheral drive circuit area, a scan line drive circuit 104 that supplies scan signals G1, G2,... Gn to the scan line 3, and a data line drive circuit 105 that supplies image signals S1, S2,. Is arranged. As shown in FIG. 8, in the substrate 10 for a liquid crystal device in which the TFT array is formed, the light shielding film 11a disposed on the quartz substrate 60 corresponding to the TFT 30 and the base insulating film 12 disposed on the light shielding film 11a. And a part of the TFT 30 disposed on the base insulating film 12 Semiconductor layer 1 A gate insulating film 2 covering the semiconductor layer 1, a gate electrode 3a and a capacitor line 3b forming part of the scanning line 3 disposed on the gate insulating film 2, and an insulating covering the gate electrode 3a and the capacitor line 3b. A film 4 is formed. Further, a data line 6 is disposed on the insulating film 4, and the data line 6 is electrically connected to the source region 1 d of the semiconductor layer 1 through a contact hole 5 formed in the insulating film 4. Further, an interlayer insulating film 7 is disposed on the data line 6, and the pixel electrode 9 a disposed on the interlayer insulating film 7 is drained from the semiconductor layer 1 by a contact hole 8 formed in the insulating film 4 and the interlayer insulating film 7. It is electrically connected to region 1e. An alignment film 16 made of a polyimide film is disposed on the front surface of the substrate on the pixel electrode 9a. The alignment film 16 is rubbed in the direction along the scanning line 3, and a detailed processing method will be described later. The semiconductor layer 1 has an LDD structure in which low-concentration impurity regions 1b and 1c are disposed on both sides so as to sandwich the channel region 1a, and high-concentration impurity regions 1d and 1e are disposed on both sides. A part of the semiconductor layer 1 functions as a capacitor electrode 1 f, and a storage capacitor 70 is formed through the capacitor line 3 b and the gate insulating film 2. On the other hand, in the detection region 110, the base insulating film 12, the insulating film 4, the interlayer insulating film 7, and the alignment film 16 formed in the display switching element region are arranged to extend, and each film is formed in a solid film shape. Has been.
[0029]
On the other hand, the counter substrate 20 is, for example, disposed on the glass substrate 80, the light shielding layer 23 provided in a lattice shape, the counter electrode 21 disposed so as to cover the light shielding layer 23, and further disposed on the counter electrode 21. Polyimide And an alignment film 22 made of The alignment film 22 is subjected to a rubbing process in a direction substantially orthogonal to the rubbing process direction applied to the alignment film 16 disposed on the TFT array substrate side.
[0030]
The alignment films 16 and 22 formed on the TFT array substrate 10 and the counter substrate 20, respectively, are rubbed using the following rubbing apparatus. Hereinafter, the TFT array substrate 10 is rubbed as an example. explain.
[0031]
As shown in FIG. 1, the rubbing device 48 of the present invention places the liquid crystal device substrate 10 on the vertical direction (arrow direction indicated by A in the figure) and a linear direction parallel to the substrate plane (B in the figure). A stage 40 as a mounting table having a moving mechanism that can move in the direction indicated by the arrow), a rubbing roller 41 in which a rubbing cloth disposed so as to contact the TFT array substrate 10 is wound around the roller, and the rubbing roller. A rotation motor (not shown). As shown in FIG. 2, a plurality of suction holes 49 are formed in the stage 40. The suction holes are formed so that the region corresponding to the peripheral portion of the substrate is dense and the region corresponding to the central portion is sparse so as to absorb warpage of the substrate 10 when the substrate 10 is placed. FIG. 2 is a diagram showing a positional relationship between the substrate 10 and the suction holes 49 in a state where the substrate 10 is disposed on the stage 40. Here, in this embodiment, the position of the rubbing roller 41 is fixed, the rubbing process is performed by moving the stage 40, and the distance between the substrate 10 and the rubbing roller 41 is controlled by the vertical movement of the stage 40. However, it is not limited to such a form. For example, the stage 40 may be fixed, and the rubbing roller 41 itself may be moved in the vertical direction and in the direction parallel to the substrate surface, or both the stage 40 and the rubbing roller 41 may be movable.
[0032]
Next, the operation of the rubbing apparatus will be described with reference to FIGS.
[0033]
First, a substrate 10 for a liquid crystal device shown in FIG. 6 in which a polyimide film to be an alignment film 16 is formed on the entire surface of the substrate is prepared. Next, as shown in step (1) of FIG. 3, the TFT array substrate 10 is conveyed onto the stage 40 of the rubbing apparatus 48 shown in FIG. Placed. At this time, the stage 40 and the rubbing roller 41 are sufficiently separated from each other.
[0034]
Next, as shown in the step (2), the substrate 10 is sucked and fixed to the stage 40 by suction from the suction holes 49 of the stage 40.
[0035]
Next, as shown in step (3), the thickness of the substrate at any one location in the detection region 101 is measured. As a measurement method, for example, the position in the vertical direction of the substrate surface can be measured by a sensor with reference to the position of the stage.
[0036]
Next, the distance between the substrate 10 and the rubbing roller 41 is calculated so as to obtain an appropriate rubbing pressure based on the measurement result of the substrate thickness measured in the step (3). Then, the stage 40 is raised as shown in step (4) so as to be this distance. At this time, the rubbing roller 41 is located on one end portion of the substrate 10, and this one end portion side is a start side of the rubbing process.
[0037]
Next, as shown in step (5), the stage is moved in a direction parallel to the substrate surface at a predetermined speed (a direction indicated by an arrow A in FIG. 1). The movement is performed in one direction from one end portion to the other end portion of the substrate as indicated by an arrow in FIG. 6, whereby the alignment film is rubbed.
[0038]
Next, when the rubbing process is completed, as shown in the steps (6) and (7), the stage is lowered and the adsorption of the substrate is released.
[0039]
Next, as shown in step (8), the rubbed substrate is unloaded from the stage 40.
[0040]
A series of operations related to the rubbing is performed for each substrate. In the present embodiment, since the substrate thickness is measured with the substrate adsorbed, the substrate thickness can be set accurately, and the rubbing process can be performed with a desired rubbing pressure.
[0041]
In this embodiment, the stage on which the substrate is placed when measuring the substrate thickness and the stage on which the substrate is placed when performing the rubbing process are the same stage. However, the rubbing stage and the substrate thickness measurement are performed. A time stage may be provided separately, and a substrate thickness measuring unit may be provided separately from the rubbing apparatus.
[0042]
(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. In the first embodiment, the rubbing condition is set by measuring the substrate thickness and the rubbing process is performed. In the second embodiment, the rubbing process is performed by setting the rotational torque value of the rubbing roller within a predetermined range. Different. In the following description, the same description as in the first embodiment is omitted.
[0043]
In the second embodiment, the liquid crystal device substrate 10 on which the alignment film is formed is rubbed using a rubbing device described below.
[0044]
As shown in FIG. 4, the rubbing device 48 of the present embodiment places the liquid crystal device substrate 10, and a vertical direction (the arrow direction indicated by A in the figure) and a linear direction parallel to the substrate plane (in the figure, A stage 40 as a mounting table having a moving mechanism movable in a direction indicated by an arrow B), a rubbing roller 41 in which a rubbing cloth arranged so as to be in contact with the liquid crystal device substrate 10 is wound around the roller, and a rubbing roller A rotating motor (not shown) for rotation. A suction hole 49 is formed in the stage 40 as in the first embodiment. Further, the rubbing device 48 is detected by a torque detection circuit 42 as a torque detection mechanism for detecting the torque of the rotation motor, a position detection circuit 43 for detecting the position of the stage, and the torque detection circuit 42 and the position detection circuit 43. Is input, and a computer 44 for processing these data, a control circuit 45 for controlling the operation of the stage based on the data processed by the computer 44, and moving the stage up and down as instructed by the control circuit 45 And a substrate surface direction moving motor 47 as a moving mechanism for moving the stage instructed by the control circuit 45 in a linear direction parallel to the substrate plane. In the torque detection circuit 42, torque is detected in the detection region 101 at one end of the substrate 10 on the rubbing process start side. In the present embodiment, the position of the rubbing roller 41 is fixed, the rubbing process is performed by moving the stage 40, and the distance between the substrate 10 and the rubbing roller 41 is controlled by the vertical movement of the stage 40. It is not limited to such a form. For example, the stage 40 may be fixed, and the rubbing roller 41 itself may be moved in the vertical direction and in a direction parallel to the substrate surface, or both the stage 40 and the rubbing roller 41 may be movable.
[0045]
Next, the operation of the rubbing apparatus will be described with reference to FIGS.
[0046]
First, the TFT array substrate 10 shown in FIG. 6 is prepared in which a polyimide film to be the alignment film 16 is formed on the entire surface of the substrate. Next, as shown in step (1) of FIG. 5, the TFT array substrate 10 is conveyed onto the stage 40 of the rubbing device 48 shown in FIG. Placed. At this time, the stage 40 and the rubbing roller 41 are sufficiently separated from each other.
[0047]
Next, as shown in step (2), the substrate 10 is sucked and fixed to the stage 40 by suction from a plurality of suction holes 49 formed on the stage 40 uniformly in the plane.
[0048]
Next, as shown in step (3), the stage 40 is raised to a predetermined position so that the substrate 10 and the rubbing roller 41 are in contact with each other. At this time, the rubbing roller 41 is positioned in the detection region 101 which is one end portion of the substrate 10, and this one end portion side is a start side of the rubbing process.
[0049]
Next, as shown in step (4), Detection area 101 The torque detection circuit 42 measures the torque value of the rotary motor of the rubbing roller. The stage position is detected by a position detection circuit 43.
[0050]
Next, as shown in step (5) and step (6), Detection area 101 The torque value and the stage position data are input to the computer 44, and it is determined whether or not the torque value is adapted to a predetermined torque value range.
[0051]
When the computer 44 determines that the predetermined torque value range is met, the control circuit 45 activates the substrate surface direction moving motor 47, and the stage moves the substrate surface at a predetermined speed as shown in step (7). It is moved in the parallel direction (the direction indicated by arrow A in FIG. 4). As shown by the arrows in FIG. 4, the movement is performed in one direction from one end of the substrate to the other end, whereby the alignment film is rubbed.
[0052]
Next, when the rubbing process is completed, the stage is lowered as shown in step (8), and the suction of the substrate is released as shown in step (9).
[0053]
Next, as shown in step (10), the rubbed substrate is unloaded from the stage 40.
[0054]
On the other hand, if it is determined in step (6) that the predetermined torque value range is not met, the vertical movement motor 46 is operated by the control circuit 45 based on the measured torque value and stage position data, and (11) As shown in the process, the stage is raised or lowered. And it returns to a process (4) again and a torque value is measured. As described above, the process (4), the process (5), the process (6), and the process (11) are repeated in order until the torque value falls within the predetermined torque value range.
[0055]
A series of operations related to the rubbing is performed for each substrate. In this embodiment, since the rotational torque value is measured with the substrate adsorbed, the desired rotational torque value can be set accurately, and the rubbing process can be performed with the desired rubbing pressure. In addition, since the rotational torque can be set in a predetermined range for each different substrate, for example, even when a plurality of substrates having thickness variations are processed, each substrate is always rubbed with a constant rotational torque value. In addition, it is possible to obtain a liquid crystal device in which there is no variation in rubbing pressure between substrates and display quality is always stable. In addition, the torque value is detected in the detection area where the rubbing process is not necessary due to the product configuration, and the rubbing process in the display area is performed with the desired torque value based on the detection of the torque value. It can be performed in a continuous operation, and manufacturing efficiency is good.
[0056]
The liquid crystal device subjected to the rubbing method described in the first embodiment or the second embodiment described above has a good display characteristic because an appropriate rubbing process is performed, and the liquid crystal alignment unevenness greatly affects the display characteristic. Particularly effective when applied to a display device.
[0057]
In the first and second embodiments, the substrate subjected to the rubbing process at the time of rubbing may be a multi-sided substrate capable of forming a plurality of liquid crystal device substrates from one substrate, or one substrate. A single substrate can be obtained in which a single substrate for a liquid crystal device can be taken from the substrate.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a rubbing apparatus according to a first embodiment.
FIG. 2 is a plan view showing a positional relationship between a suction hole of a stage and a substrate in the first embodiment and the second embodiment.
FIG. 3 is a flowchart illustrating a rubbing method according to the first embodiment.
FIG. 4 is a diagram showing a rubbing apparatus in a second embodiment.
FIG. 5 is a flowchart illustrating a rubbing method according to the second embodiment.
FIG. 6 is a schematic perspective view of a TFT array substrate.
FIG. 7 is an equivalent circuit diagram in a display switching element region of the liquid crystal device.
FIG. 8 is a longitudinal sectional view of a liquid crystal device.
[Explanation of symbols]
16, 22 ... Alignment film
10 ... TFT array substrate
20 ... Counter substrate
40 ... Stage
41 ... Rubbing roller
42 ... Torque detection circuit
43. Position detection circuit
44 ... Computer
45 ... Control circuit
46 ... Vertical movement motor
47 ... Motor for moving the substrate direction
48 ... Rubbing device
49 ... Suction hole
100 ... active area
101 ... detection area
104, 105 ... Peripheral drive circuit area

Claims (3)

(A) A liquid crystal device substrate having an alignment film is distributed in a dense state in a region corresponding to the peripheral portion of the liquid crystal device substrate and a sparse state in a region corresponding to the central portion with the alignment film facing upward. A step of mounting on a mounting table having an arranged suction hole;
(B) sucking and fixing the liquid crystal device substrate to the mounting table by sucking from the suction holes;
(C) Using the position of the mounting table as a reference, the position of the surface of the liquid crystal device substrate in the vertical direction is measured by a sensor, thereby measuring the thickness of the liquid crystal device substrate in an adsorbed and fixed state. Process,
(D) setting a rubbing condition based on the measurement result of the thickness of the substrate for a liquid crystal device, and rubbing the alignment film,
The liquid crystal device substrate is adsorbed and fixed at a higher adsorption pressure in the peripheral portion than in the central portion of the liquid crystal device substrate,
The liquid crystal device substrate comprises an active region and a detection region where the thickness of the liquid crystal device substrate is measured,
The method of rubbing a substrate for a liquid crystal device, wherein the detection region is formed at an end of the substrate for the liquid crystal device.   2. The method for rubbing a substrate for a liquid crystal device according to claim 1, wherein the active region includes a display pixel region and a peripheral drive circuit region that controls display of the display pixel region.   The method for rubbing a substrate for a liquid crystal device according to claim 1, wherein the steps (a) to (d) are performed for each different substrate for a liquid crystal device.

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