JP2015087642A - Light alignment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light alignment device that achieves a reduction in the installation area and maintenance space, and has a reduced size, excellent operability, high cleanliness, and improved throughput.SOLUTION: The present invention relates to a light alignment device 1 that irradiates an alignment film formed on a substrate 11 constituting a liquid crystal display element with ultraviolet light to cause the alignment film to be subjected to alignment processing. The light alignment device includes a substrate support 13 that can travel while supporting the substrate vertically or inclined with respect to the horizontal surface, and an ultraviolet light irradiation device 15 including a light source 15s that irradiates the substrate being conveyed by the traveling substrate support with ultraviolet light and is arranged parallel to the substrate and a polarizer 15p.

Description

  The present invention relates to a photo-alignment device used for manufacturing a liquid crystal display element, and more particularly to a photo-alignment device used for photo-alignment processing of an alignment film by ultraviolet irradiation.

  Conventionally, in a liquid crystal display element, the state of the molecular arrangement of liquid crystal is changed by the action of an electric field or the like, and this change is optically used for display. In order to align the liquid crystal in a specific direction, an alignment process is performed. Recently, a photo-alignment process is performed in which an alignment film is irradiated with polarized ultraviolet rays (see, for example, Patent Document 1).

JP 2004-144484 A

  FIG. 5 is a schematic perspective view of a conventional optical alignment apparatus 1. As shown in FIG. 5, in the conventional optical alignment apparatus 1, a substrate support 13 on which a substrate 11 having an alignment film formed on the surface thereof is fixed on the base B on the base B. Then, under the ultraviolet irradiation device 15 composed of the light source and the polarizer, it is caused to travel in the direction MD of the arrow by a known drive mechanism such as a linear motor. As a result, the substrate 11 transported under the ultraviolet irradiation device 15 is subjected to alignment treatment by being irradiated with ultraviolet rays.

  Nowadays, more and more devices are available to allow the substrate 11 to be placed at any angle with respect to the substrate support 13 by requiring the substrate 11 to be larger and the orientation angle to be freely set. The installation area is getting larger. In addition, the light source has a lifetime, and it is necessary to periodically replace the light source. However, the conventional optical alignment apparatus 1 requires a maintenance space for the length of the light source for extracting the light source.

  In addition, since the conventional photo-alignment apparatus 1 has the ultraviolet irradiation device 15 disposed above the substrate 11 to be aligned, it causes air to stay in the apparatus that is required to be cleaned. From the viewpoint of cleaning, the structure was undesirable. In addition, the sublimate generated by the decomposition reaction of the photo-alignment material forming the alignment film due to the irradiation of the ultraviolet rays on the alignment film may adhere to the ultraviolet irradiation device 15 located above and reduce the irradiation intensity. There is.

  Further, in the conventional optical alignment apparatus 1, the substrate support 13 advances only in one direction. Therefore, in order to perform the alignment process on the substrate 11, the substrate support 13 is moved from its original position, that is, from the ultraviolet irradiation apparatus 15 each time. Must be manually returned upstream of direction MD. This was the cause of insufficient throughput (production) of the apparatus. Here, in order to improve the throughput, it is necessary to automatically return the substrate support 13 after the alignment processing of the substrate 11 to the original position. However, for this purpose, for example, a mechanism for returning the substrate support 13 to the original position by, for example, configuring the drive mechanism of the substrate support 13 in a loop shape is required, and for installing the additional mechanism. Since the area is further required, there has been a problem that the installation area is greatly increased.

  Accordingly, an object of the present invention is to provide a photo-alignment apparatus that achieves a reduction in installation area and maintenance space, is compact, has excellent operability, has high cleanliness, and has improved throughput.

In order to achieve the above object, the present invention provides:
A photo-alignment apparatus for aligning the alignment film by irradiating the alignment film formed on the substrate constituting the liquid crystal display element with ultraviolet rays,
A substrate support capable of traveling while supporting the substrate in a state perpendicular or inclined with respect to a horizontal plane;
An ultraviolet irradiation device composed of a light source and a polarizing plate arranged in parallel to the substrate, for irradiating the substrate conveyed by the traveling substrate support with ultraviolet rays;
Characterized by comprising,
A photo-alignment device is provided.

  According to the present invention, since the substrate is supported in a state of being perpendicular or inclined with respect to the horizontal plane, the installation area and the maintenance space can be reduced, which is compact, excellent in operability, and clean. A high optical alignment apparatus can be provided. Further, since the installation area is reduced, even if an additional mechanism for returning the substrate to the original position is provided, the increase in the installation area of the entire apparatus is small as compared with the conventional optical alignment apparatus. For this reason, conventionally, even when the additional mechanism cannot be installed due to the restriction of the installation area, the throughput can be improved by installing the additional mechanism.

1 is a schematic top view of a photo-alignment apparatus according to a first embodiment of the present invention. 1 is a schematic side view of a photo-alignment apparatus according to a first embodiment of the present invention. The schematic top view of the photo-alignment apparatus which concerns on 2nd embodiment of this invention. The model perspective view of the photo-alignment apparatus which concerns on 3rd embodiment of this invention. The model perspective view of the conventional optical orientation apparatus.

(First embodiment)
FIG. 1 is a schematic top view showing a photo-alignment device 1 according to the first embodiment of the present invention, and FIG. 2 is a schematic side view showing the photo-alignment device 1 according to the first embodiment of the present invention. is there. Referring to FIGS. 1 and 2, the photo-alignment apparatus 1 includes two substantially rectangular flat plate-shaped substrate supports 13 including a substrate arrangement surface 2s on which a substantially rectangular flat plate-shaped substrate 11 constituting a liquid crystal display element is disposed. Prepare. The substrate support 13 is moved on the base B by a known drive mechanism such as a linear motor so as to travel in a loop clockwise around the travel route R that is a rounded rectangle in the first embodiment. It is attached to the base B via two legs 13l.

  In FIG. 1, the substrate supports 13 located at various locations are indicated by dotted lines so that the travel trajectory of the substrate support 13 can be understood.

  In the first embodiment, the substrate support 13 is arranged in a so-called vertical orientation, that is, is arranged perpendicular to the horizontal plane. Accordingly, the substrate 11 is supported by the substrate arrangement surface 13s of the substrate support 13 perpendicular to the horizontal plane.

  The substrate support 13 is preferably made of stainless steel (SUS), particularly fluorine-coated stainless steel, or alumina (ceramic). This is because the generation of static electricity can be suppressed.

  In the first embodiment, several grooves (not shown) are formed on the substrate placement surface 13 s of the substrate support 13, and a vacuum line that is evacuated by a vacuum pump or the like is connected to the substrate support 13. The inside of the groove communicates with the inside of the groove. Then, the substrate 11 is vacuum-adsorbed and held by sucking air in the groove located between the substrate arrangement surface 13s and the substrate 11 arranged on the substrate arrangement surface 13s and making the inside of the groove negative pressure. can do.

  At this time, when the substrate 11 cannot be received while the substrate support 13 is placed in a vertical position due to insufficient suction capability by the vacuum line, when the substrate support 13 receives the substrate 11, the substrate placement surface 13s is You may comprise the board | substrate support body 13 so that it may incline and may approach a horizontal surface.

  The photo-alignment device 1 according to the first embodiment includes an ultraviolet irradiation device 15 fixed to the base B on the side of the travel route R of the substrate support 13. The ultraviolet irradiation device 15 irradiates the substrate 11 conveyed on the side with ultraviolet rays, and includes a light source 15 s arranged in parallel to the substrate 11 and a polarizing plate 15 p. In the photo-alignment device 1 according to the first embodiment, the light source 15s used for the ultraviolet irradiation device 15 is a plurality of short arc UV lamps. The light source 15s may be other than the short arc UV lamp, such as a long arc UV lamp or an excimer laser.

  Further, the entire photo-alignment device 1 according to the first embodiment is covered with a cover (not shown). Furthermore, in 1st embodiment, in order to clean the air in a cover, the blower outlet (not shown) to which filters, such as a HEPA filter and a ULPA filter, were attached to the ceiling part of the cover is provided. With such a configuration, the air cleaned through the filter can be blown into the photo-alignment apparatus 1, particularly at an irradiation position PI described later.

  Hereafter, the procedure for aligning the alignment film formed on the substrate 11 by the optical alignment apparatus 1 according to the first embodiment will be described.

  First, the substrate 11 on which the alignment film is formed by applying the photo-alignment material on the surface in the upstream process is introduced into the photo-alignment apparatus 1. And the board | substrate 11 introduced into the optical orientation apparatus 1 can take a desired polarization angle with respect to the polarizing plate 15p by the articulated robot 17a installed beside the base B in the board | substrate receiving position PR. In order to be able to do so, it is arranged by being suction fixed to the substrate arrangement surface 13 s of the substrate support 13. In other words, the substrate 11 can be arranged at any angle α (FIG. 2) with respect to the substrate arrangement surface 13s.

Next, the substrate support 13 on which the substrate 11 is supported travels from the substrate receiving position PR toward the light irradiation position PI. The substrate 11 is subjected to orientation treatment by being irradiated with ultraviolet rays from the light source 15s through the polarizing plate 15p while being transported by the ultraviolet irradiation device 15 at the light irradiation position PI. Here, in the present invention, “being oriented” specifically refers to irradiating polarized ultraviolet rays to a photo-alignment material composed of, for example, an isotropic polymer applied to the substrate 11, It means that a polymer chain is formed only in a direction orthogonal to the polarization direction by decomposing the polymer oriented in the polarization direction. Thereby, in the first embodiment, when the polarization direction of ultraviolet rays is parallel to the traveling direction MD of the substrate support 13, for example, the direction in which the polymer chain is formed (orientation direction) is the traveling direction of the substrate support 13. The direction is perpendicular to the MD, that is, the direction of (90−α) ° with respect to the longitudinal direction of the substrate 11. Here, the traveling speed of the substrate support 13, the wavelength of the irradiation light from the ultraviolet irradiation device 15, the light amount, etc. are determined according to the type and size of the substrate 11 and the alignment film, For example, in the first embodiment, the traveling speed of the substrate support 13 is constant, 10 mm / sec, and the ultraviolet irradiation device 15 irradiates ultraviolet rays having a main wavelength of 254 nm polarized by the polarizing plate 15p. The accumulated light quantity is 800 mJ / cm ² .

  Thereafter, the substrate support 13 that supports the substrate 11 subjected to the alignment treatment travels from the light irradiation position PI toward the substrate payout position PO. The substrate 11 is peeled from the substrate placement surface 13s by the articulated robot 17b installed beside the base B at the substrate dispensing position PI, and sent to the next process.

  Next, the substrate support 13 from which the substrate 11 has been discharged travels from the substrate discharge position PO toward the substrate receiving position PR, and the next substrate 11 can be continuously received at the substrate receiving position PR.

  From this, the effect show | played by the optical orientation apparatus 1 which concerns on 1st embodiment is demonstrated.

  (1) A conventional photo-alignment device in which the substrate support 13 is vertically placed on the base B and the substrate 11 is arranged so as to be horizontal by arranging the substrate 11 so as to be perpendicular to the horizontal plane. Compared with 1, the space for installing the photo-alignment device 1 can be greatly reduced.

(2) Since the substrate support 13 is placed vertically, the ultraviolet irradiation device 15 can also be installed vertically. Thereby, maintenance such as replacement of the light source 15s is easy, and the maintenance space can be greatly reduced. As an example, the initial illuminance of the light source 15s was 450 mJ / cm ² , but the light source 15s was replaced because the irradiance decreased to 70% of the initial illuminance after 700 hours of use. In the conventional optical alignment apparatus 1, a maintenance space corresponding to the length of the light source 15 s for drawing out the light source 15 s is necessary. However, in the optical alignment apparatus 1 according to the first embodiment, the side surface of the ultraviolet irradiation apparatus 15. Thus, the light source 15s can be easily replaced, and the maintenance space can be reduced.

  (3) Moreover, in the conventional photo-alignment apparatus 1, since the ultraviolet irradiation device 15 was positioned on the substrate 11 to be subjected to the alignment treatment as described above, the alignment film is formed by irradiating the alignment film with ultraviolet rays. The ultraviolet irradiation device 15 is contaminated by the sublimate generated by the decomposition reaction of the photo-alignment material forming the. However, in the photo-alignment apparatus 1 according to the first embodiment, since the ultraviolet irradiation device 15 is located beside the substrate 11 to be aligned, the sublimate rises along the substrate 11 and therefore adheres to the light source 15s. Is suppressed. For this reason, it is suppressed that the ultraviolet irradiation device 15 is contaminated by the sublimate. Therefore, in the photo-alignment device 1 according to the first embodiment, the frequency of cleaning the ultraviolet irradiation device 15 is reduced, and as a result, maintenance is easy.

  (4) In addition, in the photo-alignment apparatus 1 according to the first embodiment, as described above, the air outlet having the filter attached to the ceiling portion of the cover is provided, and the air outlet is cleaned from the air outlet. Air can be blown into the photo-alignment apparatus 1, particularly at the irradiation position PI. Accordingly, since there is no ultraviolet irradiation device 15, that is, no obstacle, above the substrate as in the conventional photo-alignment device 1 (FIG. 5), the cleaned air has an ideal flow from the top to the bottom in the device. And air retention is suppressed. As a result, a cleaned device can be provided.

  (5) Moreover, in the optical alignment apparatus 1 which concerns on 1st embodiment, it has a mechanism which returns the board | substrate support body 13 after completion | finish of the alignment process of the board | substrate 11 to an original position using a loop mechanism. A process of receiving the substrate 11 at the receiving position PR, a process of aligning the alignment film formed on the substrate 11 at the irradiation position PI, and a process of discharging the processed substrate 11 to the downstream process at the substrate discharging position PO are continuously performed. Can be repeated. As a result, the photo-alignment apparatus 1 according to the first embodiment has a higher throughput than the conventional photo-alignment apparatus 1.

  In a later step, a liquid crystal display element can be manufactured by sandwiching a liquid crystal material using the substrate 11 prepared as described above. The liquid crystal display element manufactured using the photo-alignment apparatus 1 according to the first embodiment is compared with a liquid crystal display element manufactured by a rubbing method, which is an alignment method of an alignment film that has been generally used. Thus, high-quality orientation quality can be obtained. Furthermore, in the liquid crystal display element produced using the photo-alignment device according to the first embodiment, the retention of air is suppressed as described above, and the inside of the device is cleaned. Since the defect with the dust as the core, which is seen in the liquid crystal display element subjected to the alignment treatment by the alignment apparatus 1, does not occur, the quality of the liquid crystal display element can be further improved.

  In the first embodiment, the substrate support 13 is mounted on the base B so as to travel in a loop on the travel route R. However, the substrate support 13 is the conventional optical alignment apparatus 1. Like, it may be attached to base B so that it may run only in one direction. In this case, although the throughput is sacrificed to some extent, the installation area of the apparatus can be further reduced.

  In addition, the optical alignment apparatus 1 according to the first embodiment is configured such that the substrate support 13 travels. However, the substrate support 13 is fixed, and the ultraviolet irradiation device 15 is the substrate support 13. You may comprise so that it may drive | work around and may irradiate the ultraviolet-ray with respect to the board | substrate 11 currently supported by the board | substrate support body 13. As shown in FIG.

  The photo-alignment apparatus 1 according to the first embodiment includes only one ultraviolet irradiation device 15, but may include a plurality of ultraviolet irradiation devices 15. As a result, the plurality of substrates 11 can be processed while the substrate support 13 goes around the travel route R. Alternatively, the integrated light quantity for one substrate 11 can be increased.

(Second embodiment)
Hereafter, the optical alignment apparatus 1 which concerns on 2nd embodiment of this invention is demonstrated, referring FIG. FIG. 3 is a schematic top view of the optical alignment apparatus 1 according to the second embodiment of the present invention. In addition, about 2nd embodiment, a different point from 1st embodiment is mainly demonstrated. The second embodiment is different from the first embodiment in that the substrate support 13 moves in translation along a substantially rectangular travel route R.

  In the optical alignment apparatus 1 according to the second embodiment, there is a mechanism for rotating the substrate support 13 such as the driving apparatus of the optical alignment apparatus 1 according to the first embodiment by translating the substrate support 13. It becomes unnecessary, and the photo-alignment device 1 can be configured more simply.

  Since the effect exhibited by the photo-alignment device 1 according to the second embodiment is the same as that of the photo-alignment device 1 according to the first embodiment, the description thereof is omitted.

(Third embodiment)
Hereafter, the optical alignment apparatus 1 which concerns on 3rd embodiment of this invention is demonstrated, referring FIG. FIG. 4 is a schematic perspective view of the photo-alignment apparatus 1 according to the third embodiment of the present invention. In addition, about 3rd embodiment, a different point from 2nd embodiment is mainly demonstrated. The third embodiment is different from the second embodiment in that the substrate support 13 includes a substrate arrangement surface 13s that is inclined with respect to a horizontal plane.

  In the third embodiment, since the substrate arrangement surface 13s of the substrate support 13 is inclined with respect to the horizontal plane, the substrate 11 arranged thereon is inclined with respect to the horizontal plane. Supported by

  Referring to FIG. 4, the ultraviolet irradiation device 15 includes a light source 15 s arranged in parallel to the substrate 11, and as a result, is inclined with respect to a horizontal plane similarly to the substrate arrangement surface 13 s of the substrate support 13. .

  In the optical alignment apparatus 1 according to the third embodiment, the substrate arrangement surface 13 s of the substrate support 13 is inclined, so that the substrate arrangement surface 13 s is configured parallel to the horizontal plane, rather than the optical alignment apparatus 1. The installation area can be reduced. Further, since the substrate placement surface 13s is not perpendicular to the horizontal plane but inclined, the substrate placement surface by the articulated robots 17a and 17b is compared with the optical alignment apparatus according to the first and second embodiments. It is easy to transfer the substrate 11 to 13s.

  The inclination angle of the substrate arrangement surface 13s can be arbitrarily determined in consideration of the installation area of the photo-alignment apparatus 1 and the ease of delivery of the substrate 11 to the substrate arrangement surface 13s. Further, in order to make the substrate 11 easier to receive, the substrate support 13 inclines the substrate arrangement surface 13s so that the substrate arrangement surface 13s is parallel to or close to the horizontal plane when receiving the substrate 11, and then formed on the substrate 11. The tilt angle may be changed so that the substrate placement surface 13s is tilted so as to be perpendicular to or close to the horizontal plane when the alignment film is subjected to the alignment treatment.

  Since the effect exhibited by the photo-alignment apparatus 1 according to the third embodiment is the same as that of the photo-alignment apparatus 1 according to the first embodiment, description thereof is omitted.

  In the above-described embodiment, the substrate 11 is supported on the substrate placement surface 13s of the substrate support 13 and the substrate 11 is transported, but instead of the substrate support 13 as described above, for example, driven by a linear motor drive mechanism. A plurality of pins protruding from the base B may be transported by running the substrate 11 while being sucked and fixed by a suction port provided at the tip thereof and communicating with the vacuum line. Thereby, generation | occurrence | production of static electricity can further be suppressed.

DESCRIPTION OF SYMBOLS 1 Optical alignment apparatus 11 Substrate 13 Substrate support 15 Ultraviolet irradiation device 15s Light source 15p Polarizing plate

Claims (2)

A photo-alignment apparatus for aligning the alignment film by irradiating the alignment film formed on the substrate constituting the liquid crystal display element with ultraviolet rays,
A substrate support capable of traveling while supporting the substrate in a state perpendicular or inclined with respect to a horizontal plane;
An ultraviolet irradiation device composed of a light source and a polarizing plate arranged in parallel to the substrate, for irradiating the substrate conveyed by the traveling substrate support with ultraviolet rays;
Characterized by comprising,
Photo-alignment device. Further, the substrate support is provided with a mechanism that travels in a loop shape so as to return from the position after the end of the alignment process to the position before the start of the alignment process.
The photo-alignment apparatus according to claim 1.

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