JP2009053587A - Liquid crystal device manufacturing apparatus and liquid crystal device manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide manufacturing equipment of liquid crystal device and a manufacturing method of liquid crystal device capable of improving the productivity by efficiently removing gas included in liquid crystal in a short time. <P>SOLUTION: The manufacturing equipment of liquid crystal device in which the liquid crystal is interposed between a pair of substrates attached to each other via a sealing material comprises: a stage part of retaining a substrate on which the liquid crystal is dropped down, of a pair of substrates; an ultra-sonic vibrator of irradiating ultrasonic waves onto the stage part; a vacuum chamber capable of making the inner part thereof into the vacuum state; and an attachment device of attaching the pair of substrates to each other via the sealing material in the vacuum chamber. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an apparatus for manufacturing a liquid crystal device in which a liquid crystal is sandwiched between a pair of substrates, and a method for manufacturing the liquid crystal device.

  A liquid crystal device which is an electro-optical device is configured by sandwiching liquid crystal between a pair of substrates made of a glass substrate, a quartz substrate, or the like.

  In a liquid crystal device, for example, a switching element such as a thin film transistor (hereinafter referred to as TFT) and a pixel electrode are arranged in a matrix on one substrate, and a counter electrode is arranged on the other substrate so that the gap between the two electrodes By changing the orientation of the liquid crystal intervening in accordance with the image signal, the transmitted light is modulated to enable image display.

  In such a liquid crystal device, as a method of interposing liquid crystal between a pair of substrates, after dropping the liquid crystal on at least one substrate, the other substrate is sealed in a frame shape so as to sandwich the liquid crystal under vacuum. A liquid crystal dropping method (ODF) in which materials are bonded together is known. This liquid crystal dropping method is disclosed in, for example, Japanese Patent Application Laid-Open Nos. 2004-272086 and 2002-323694.

  Incidentally, gases such as air, oxygen, and nitrogen are dissolved in the liquid crystal sealed in the liquid crystal device. If bubbles generated due to the gas dissolved in the liquid crystal are generated in the liquid crystal device, alignment failure of the liquid crystal and the like may occur, and display failure may occur in the liquid crystal device.

As a degassing method for removing a gas dissolved in a viscous material such as liquid crystal, for example, a method in which a viscous material is left in a vacuum, or as disclosed in JP-A-2002-80005 is disclosed. There is known a method of separating viscous materials having different densities and air by a centrifugal force.
JP 2004-272086 A JP 2002-323694 A Japanese Patent Laid-Open No. 2002-80005

  However, when the liquid crystal is left in a vacuum for a deaeration process, the dissolved gas cannot be removed in a short time, and if an attempt is made to shorten the manufacturing time, bubbles are generated in the liquid crystal. As a result, there is a problem that the yield of the liquid crystal device is deteriorated.

  In addition, when performing a method of separating liquid crystal and gas by centrifugal force, the liquid crystal must be transferred between a device for degassing and a device for bonding the substrates. There is a problem that expectations are dissolved in the liquid crystal.

  The present invention has been made in view of the above problems, and a liquid crystal device manufacturing apparatus and a liquid crystal device capable of improving productivity by efficiently removing gas contained in liquid crystals in a short time. An object is to provide a manufacturing method.

  An apparatus for manufacturing a liquid crystal device according to the present invention is an apparatus for manufacturing a liquid crystal device in which a liquid crystal is sandwiched between a pair of substrates bonded via a sealing material, and the liquid crystal of the pair of substrates is A stage unit for holding the dropped substrate, an ultrasonic transducer for irradiating the stage unit with ultrasonic waves, a vacuum chamber capable of reducing the inside thereof, and the pair of substrates in the vacuum chamber And a bonding means for bonding together through the sealing material.

  In addition, a method for manufacturing a liquid crystal device according to the present invention is a method for manufacturing a liquid crystal device in which a liquid crystal is sandwiched between a pair of substrates bonded via a sealing material, and includes at least one of the pair of substrates. A liquid crystal dropping step of dropping liquid crystal on one substrate, an ultrasonic irradiation step of irradiating the substrate on which the liquid crystal has been dropped with an ultrasonic wave, and a bonding step of bonding the pair of substrates through a sealing material under vacuum It is characterized by comprising.

  According to such a configuration of the present invention, the liquid crystal dropped on the substrate becomes highly fluid when irradiated with ultrasonic waves, and further, the liquid crystal is stirred by vibration, so that it is dissolved in the liquid crystal. The gas is efficiently removed in a short time, and the productivity of the liquid crystal device can be improved. Further, according to the present invention, the stage unit is disposed in the vacuum chamber, and the bonding apparatus is configured so that the liquid crystal held by the stage unit is dropped on the other substrate via the sealing material. It is preferable to bond the substrates.

  In the present invention, it is preferable that the ultrasonic irradiation step is performed under vacuum.

  According to such a configuration, it is possible to perform a deaeration process on the liquid crystal immediately before the liquid crystal is sandwiched between the pair of substrates, and it is possible to bond the pair of substrates in a vacuum state. It is. Therefore, the gas does not dissolve again in the liquid crystal after the deaeration process by ultrasonic irradiation.

  Embodiments of the present invention will be described below with reference to the drawings. The liquid crystal device according to the present embodiment is a tilted vertical alignment type liquid crystal display device that controls liquid crystal having negative dielectric anisotropy so as to be aligned substantially vertically when no voltage is applied, so-called VA mode liquid crystal display device. It is. In each drawing used for the following description, the scale is different for each member in order to make each member a size that can be recognized on the drawing.

  First, the overall configuration of the liquid crystal device 100 of the present embodiment will be described with reference to FIGS. 1 and 2. Here, FIG. 1 is a plan view of the liquid crystal device when the TFT array substrate is viewed from the side of the counter substrate together with each component configured thereon. 2 is a cross-sectional view taken along the line H-H ′ of FIG. 1. In the present embodiment, as an example of the liquid crystal device, a transmissive liquid crystal display device of a TFT active matrix driving method with a built-in driving circuit is taken as an example.

  In the liquid crystal device 100, the liquid crystal 50 is sandwiched between the TFT array substrate 10 made of glass, quartz, or the like and the counter substrate 20, and the alignment state of the liquid crystal 50 is changed, whereby the counter substrate 20 is placed in the image display region 10a. The light incident from the side is modulated and emitted from the TFT array substrate 10 side, whereby an image is displayed in the image display region 10a.

  1 and 2, in the liquid crystal device 100 according to the present embodiment, the TFT array substrate 10 and the counter substrate 20 are arranged to face each other. The TFT array substrate 10 and the counter substrate 20 are bonded to each other by a frame-shaped sealing material 52 provided in a seal region located around the image display region 10a. A liquid crystal 50 is sandwiched between them. Further, in the sealing material 52, gap materials such as glass fibers and glass beads for setting the distance between the TFT array substrate 10 and the counter substrate 20 to a predetermined value are scattered.

  A light-shielding frame light-shielding film 53 that defines the frame area of the image display area 10a is provided on the counter substrate 20 side in parallel with the inside of the seal area where the sealing material 52 is disposed. A part or all of the frame light shielding film 53 may be provided as a built-in light shielding film on the TFT array substrate 10 side.

  In the present embodiment, there is a non-display area located around the image display area 10a. In the non-display area, the data line driving circuit 101 and the mounting terminal 102 are provided along one side of the TFT array substrate 10 in an area located outside the seal area where the seal material 52 is disposed. Although not shown, by connecting a flexible printed circuit board or the like to the mounting terminals 102 exposed on the surface of the TFT array substrate 10, electrical connection between the liquid crystal device 100 and the outside such as a control device of an electronic device can be achieved. Done.

  The scanning line driving circuit 104 is provided along two sides adjacent to one side of the TFT array substrate 10 on which the data line driving circuit 101 and the mounting terminals 102 are provided, and is covered with the frame light shielding film 53. . Further, the TFT array substrate 10 is provided along the remaining side, that is, the side facing the one side of the TFT array substrate 10 on which the data line driving circuit 101 and the mounting terminal 102 are provided, and is provided so as to be covered with the frame light shielding film 53. The two scanning line driving circuits 104 are electrically connected to each other by the plurality of wirings 105.

  Further, at least one corner of the counter substrate 20 is provided with a vertical conductive material 106 that functions as a vertical conductive terminal for electrical connection between the TFT array substrate 10 and the counter substrate 20. On the other hand, the TFT array substrate 10 is provided with vertical conduction terminals in a region corresponding to these vertical conduction members 106. Electrical connection is made between the TFT array substrate 10 and the counter substrate 20 via the vertical conductive member 106 and the vertical conductive terminal.

  In FIG. 2, an inorganic alignment film 16 is formed on the TFT array substrate 10 on the pixel electrode 9a after the formation of pixel switching TFTs, scanning lines, data lines, and the like. On the other hand, on the counter substrate 20, in addition to the counter electrode 21, a lattice-shaped or striped light-shielding film 23 and an inorganic alignment film 22 are formed on the uppermost layer. As will be described in detail later, the inorganic alignment films 16 and 22 formed on the surfaces of the TFT array substrate 10 and the counter substrate 20 that are in contact with the liquid crystal 50 are thin films made of a light-transmitting inorganic material such as SiO 2. . The inorganic alignment films 16 and 22 are films for regulating the alignment of the liquid crystal 50, and the liquid crystal 50 takes a predetermined alignment state between the pair of inorganic alignment films 16 and 22.

  The liquid crystal device 100 according to the present embodiment employs a tilted vertical alignment mode using a liquid crystal having negative dielectric anisotropy, a so-called VA mode. In addition, a polarizing film, a retardation film, and a polarizing film are respectively provided on the side on which the incident light of the counter substrate 20 enters and on the side on which the outgoing light of the TFT array substrate 10 is emitted, depending on the normally white mode / normally black mode. A plate or the like is arranged in a predetermined direction.

  An inorganic alignment film composed of an inorganic material such as SiO2 is superior in light resistance and heat resistance to an alignment film composed of an organic material such as polyimide, so that there is no deterioration over time and display quality does not deteriorate. A liquid crystal device can be realized.

  Next, with reference to FIG. 3 to FIG. 5, the manufacturing method of the liquid crystal device described above, specifically, the bonding process between the TFT array substrate 10 and the counter substrate 20 in the liquid crystal device 100 will be mainly described. FIG. 3 is a flowchart showing a method for manufacturing the liquid crystal device of the present embodiment. Since the manufacturing method of the liquid crystal device other than the bonding step is well known, the description thereof will be omitted or briefly described.

  First, a laminated structure is formed on the TFT array substrate 10 (step S1). As described above, the laminated structure includes data lines, scanning lines, TFTs, pixel electrodes 9a, inorganic alignment films 16, and the like, and is formed by, for example, film formation by CVD or sputtering, patterning by photolithography, heat treatment, or the like. .

  On the other hand, a laminated structure is also formed on the counter substrate 20 (step S2). The laminated structure includes a common electrode, a color filter, a black matrix, an inorganic alignment film 22, and the like, and is formed by, for example, film formation by CVD or sputtering, patterning by photolithography, heat treatment, or the like.

  Next, a frame-shaped sealing material 52 surrounding the image display region 10a is formed on the TFT array substrate 10 (step S3). The sealing material 52 is formed by a dispensing method, a printing method, or the like.

  Next, a predetermined amount of liquid crystal 50 is dropped and supplied into the region surrounded by the sealing material 52 on the TFT array substrate 10 (step S4).

  The TFT array substrate 10 in a state in which the liquid crystal 50 is dropped and the counter substrate 20 are positioned and bonded to each other by a bonding apparatus 200 having a bonding means, which is a liquid crystal device manufacturing apparatus, which will be described in detail later. (Step S5). Thus, the liquid crystal device 100 is completed.

  Hereinafter, the bonding process between the TFT array substrate 10 and the counter substrate 20 in step S5 described above will be described in detail.

  In the bonding step of the present embodiment, the TFT array substrate 10 and the counter substrate 20 are bonded by the bonding apparatus 200 shown in FIG. In FIG. 4, the upward direction is referred to as “upward” as opposed to the paper surface. The bonding apparatus 200 includes bonding means that is a mechanism for bonding the TFT array substrate 10 and the counter substrate 20 in a vacuum.

  The laminating apparatus 200 includes an airtight vacuum chamber 210 configured by being divided into a canopy portion 201 and a bottom surface portion 202, a vacuum pump 207 that discharges gas from the vacuum chamber 210 through a discharge port 205, A valve 206 for opening and closing the discharge port 205 is provided.

  The vacuum chamber 210 includes a fixed disk-shaped metal bottom part 202, and a dome-shaped canopy part 201 that is moved vertically relative to the bottom part by a vacuum chamber opening / closing mechanism part 203. It is comprised and comprises.

  When the canopy 201 is moved downward by the vacuum chamber opening / closing mechanism 203 and the bottom surface of the canopy 201 is in close contact with the top surface of the bottom 202, an airtight space is formed in the vacuum chamber 210. A resin O-ring 204 for keeping the inside of the vacuum chamber 210 airtight is disposed in a region where the canopy 201 and the bottom 202 are in contact with each other.

  When the inside of the vacuum chamber 210 is kept airtight, by opening the valve 206, the gas in the vacuum chamber 210 is discharged from the discharge port 205 by the vacuum pump 207, and the inside of the vacuum chamber 210 is around the bonding apparatus 200. The pressure is reduced with respect to the atmospheric pressure.

  On the other hand, when the canopy 201 is moved upward by the vacuum chamber opening / closing mechanism 203 and the canopy 201 is separated from the bottom 202, the substrate is carried into and out of the vacuum chamber 210 by a transfer device (not shown). Is possible.

  In the vacuum chamber 210, there are disposed a lower substrate holding stage 211 and an upper substrate holding stage 212, which are stage portions for positioning and holding the TFT array substrate 10 and the counter substrate 20 with their bonding surfaces facing each other. . The lower substrate holding stage 211 and the upper substrate holding stage 212 are made of a hard material such as metal or ceramic, and have a mechanism for holding a substrate such as a vacuum chuck, a mechanical chuck, or an electrostatic chuck.

  The lower substrate stage 211 is closely fixed on the bottom surface portion 202 of the vacuum chamber 210 by, for example, bolt fastening.

  On the other hand, the upper substrate stage 212 is configured to be movable in the vertical and vertical directions independently of the canopy unit 201 by the stage moving mechanism unit 214. In the present embodiment, the upper substrate stage 212 is supported by a slide shaft portion 213 that penetrates the central portion of the canopy portion 201 in the vertical direction.

  The slide shaft portion 213 is a cylindrical shaft that is driven in the vertical vertical direction by the stage moving mechanism portion 214, and the inside of the vacuum chamber 210 is kept airtight by a vacuum seal 215 provided at a portion that penetrates the canopy portion 201. It can be moved in the vertical direction relative to the canopy 201.

  That is, the upper substrate stage 212 can be moved vertically in the vertical direction even when the vacuum chamber 210 is in a vacuum state.

  And in the bonding apparatus 200 which is the manufacturing apparatus of the liquid crystal device of this embodiment, the ultrasonic transducer unit 220 is fixed to the lower side of the bottom surface part 220 by bolt fastening. The ultrasonic transducer unit 220 is an apparatus that is electrically connected to an oscillator (not shown) and transmits ultrasonic waves having a predetermined frequency and output.

  The ultrasonic transducer unit 220 is disposed so that the ultrasonic wave to be transmitted is irradiated to the bottom surface portion 202 and the lower substrate stage 211 fixed on the bottom surface portion.

  The bonding apparatus 200 is also provided with a mechanism for relatively moving and positioning the TFT array substrate 10 and the counter substrate 20, which is a known bonding process used in the manufacturing process of the liquid crystal device. Since it is the same as that of the aligning apparatus, the description thereof will be omitted in this embodiment.

  Details of the bonding process performed in the bonding apparatus 200 having the above-described configuration will be described with reference to the flowchart of FIG.

  In the bonding process, first, in step S11, the TFT array substrate 10 and the counter substrate 20 are carried into the vacuum chamber 210 of the bonding apparatus 200 by the transfer device.

  Specifically, the TFT array substrate 10 in a state where the sealing material 52 is applied and the liquid crystal 50 is dropped onto the lower substrate stage 211 in the vacuum chamber 210 where the canopy 201 is lifted upward and opened is carried in. To be fixed. The counter substrate 20 is also fixed to the upper substrate stage 212 so as to oppose the TFT array substrate 10 by the transfer device.

  Next, in step S <b> 12, an ultrasonic oscillator (not shown) is operated, and ultrasonic waves having a predetermined frequency and output are transmitted from the ultrasonic transducer unit 220. Here, the ultrasonic wave sent out from the ultrasonic transducer unit 220 travels through the bottom surface part 202 and the lower substrate stage 211 made of a hard material such as metal and is irradiated onto the TFT array substrate 10.

  Next, in step S13, the canopy 201 is lowered to bring the vacuum chamber 210 into an airtight state, the valve 206 is opened, and vacuuming is performed until the inside of the vacuum chamber 210 reaches a predetermined degree of vacuum.

  When the inside of the vacuum chamber 210 reaches a predetermined degree of vacuum, transmission of ultrasonic waves by the ultrasonic transducer unit 220 is stopped, and then the upper substrate stage 212 is lowered to face the TFT array substrate 10 in step S14. The substrate 20 is bonded.

Next, in step S15, the inside of the vacuum chamber 210 is opened to the atmosphere. In step S16, the canopy 201 and the upper substrate stage 212 are raised, and the TFT array substrate 10 and the counter substrate 20 in a bonded state are carried out by the transfer device. To do.
This is the end of the bonding process of the present embodiment.

  In the present embodiment described above, ultrasonic waves are applied to the TFT array substrate 10 fixed on the lower substrate stage 211 for a period until the inside of the vacuum chamber 210 reaches a predetermined degree of vacuum. Here, since the TFT array substrate 10 is made of hard glass, quartz, or the like, the irradiated ultrasonic waves are also applied to the liquid crystal 50 dropped on the TFT array substrate 10.

  The liquid crystal 50 becomes more fluid when irradiated with ultrasonic waves, and the liquid crystal 50 is agitated by vibration. Therefore, the gas dissolved in the liquid crystal 50 is compared with the case where the gas is left in a vacuum. It is efficiently removed (degassed) in a shorter time. That is, the yield of the liquid crystal device 100 can be improved.

  Further, the period of irradiating the ultrasonic waves for degassing the liquid crystal 50 is performed during a waiting time until the inside of the vacuum chamber 210 reaches a predetermined degree of vacuum, thereby extending the processing time of the conventional manufacturing process. The deaeration process of the liquid crystal 50 can be performed without this.

  In addition, the deaeration process of the liquid crystal 50 is performed immediately before the liquid crystal 50 is sealed between the TFT array substrate 10 and the counter substrate 20, and at the end of the deaeration process, a predetermined degree of vacuum is obtained. Therefore, the gas does not dissolve again in the liquid crystal 50 after the deaeration process.

  Therefore, according to the present embodiment, it is possible to efficiently remove the gas contained in the liquid crystal in a short time and improve productivity.

  In the above-described embodiment, the liquid crystal 50 is described as being dropped on the TFT array substrate 10, but the liquid crystal may be dropped on the counter substrate 20. In FIG. 4, the TFT array substrate 10 is supported with the surface on which the liquid crystal 50 is dropped facing upward, but the position of the TFT array substrate 10 and the counter substrate 20 is switched to drop the liquid crystal 50. The structure may be such that the surface faces downward. In this case, it goes without saying that the vibrator unit 220 is disposed so as to be able to irradiate the upper substrate stage 212 with ultrasonic waves.

  In addition, the ultrasonic transducer unit 220 is disposed outside the vacuum chamber 220 in the present embodiment. For example, the transducer unit 220 is arranged in the vacuum chamber 210 so as to directly contact the lower substrate stage 211. It may be provided.

  Further, in the present embodiment, the ultrasonic wave irradiation to the liquid crystal 50 is performed only during the vacuuming period. However, for example, the ultrasonic wave irradiation may be performed until the bonding of the substrates is completed. In addition, the timing of starting the irradiation with ultrasonic waves is not limited to the present embodiment as long as the substrates are not bonded to each other.

  In the above-described embodiment, the VA mode active matrix driving type transmissive liquid crystal panel using TFTs has been described as a liquid crystal device. However, the present invention is not limited to this, and other types of liquid crystal devices are used. The present invention can also be applied to the manufacturing apparatus and the manufacturing method.

  The liquid crystal device may be a display device for forming an element on a semiconductor substrate, for example, LCOS (Liquid Crystal On Silicon). In LCOS, a single crystal silicon substrate is used as an element substrate, and a transistor is formed on a single crystal silicon substrate as a switching element used for a pixel or a peripheral circuit. In addition, a reflective pixel electrode is used for the pixel, and each element of the pixel is formed below the pixel electrode.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. A manufacturing apparatus and a manufacturing method are also included in the technical scope of the present invention.

FIG. 3 is a plan view of the electro-optical device when the TFT array substrate is viewed from the counter substrate side together with the components configured thereon. It is H-H 'sectional drawing of FIG. It is a flowchart which shows the manufacturing method of a liquid crystal device. It is a figure explaining schematic structure of a bonding apparatus. It is a flowchart of a bonding process.

Explanation of symbols

10 TFT array substrate, 20 counter substrate, 50 liquid crystal, 52 sealing material, 200 bonding apparatus, 201 canopy section, 202 bottom surface section, 203 vacuum chamber opening / closing mechanism section, 204 O-ring, 205 discharge port, 206 valve, 207 vacuum pump , 210 vacuum chamber, 211 lower substrate stage, 212 upper substrate stage, 213 slide shaft, 214 stage moving mechanism, 215 vacuum seal, 220 ultrasonic transducer unit

Claims (4)

An apparatus for manufacturing a liquid crystal device, wherein a liquid crystal is sandwiched between a pair of substrates bonded via a sealing material,
A stage unit for holding a substrate on which the liquid crystal is dropped from the pair of substrates;
An ultrasonic transducer for irradiating the stage part with ultrasonic waves;
A vacuum chamber capable of depressurizing the inside;
An apparatus for manufacturing a liquid crystal device, comprising: a bonding unit that bonds the pair of substrates through the sealant in the vacuum chamber. The stage portion is disposed in the vacuum chamber,
The apparatus for manufacturing a liquid crystal device according to claim 1, wherein the bonding unit bonds the other substrate to the substrate on which the liquid crystal held by the stage unit is dropped via the sealing material. . A method for manufacturing a liquid crystal device in which a liquid crystal is sandwiched between a pair of substrates bonded via a sealing material,
A liquid crystal dropping step of dropping liquid crystal on at least one of the pair of substrates;
An ultrasonic irradiation step of irradiating the substrate on which the liquid crystal is dropped with an ultrasonic wave;
And a bonding step of bonding the pair of substrates through a sealing material under vacuum.   The method of manufacturing a liquid crystal device according to claim 3, wherein the ultrasonic wave irradiation step is performed under vacuum.

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