JP4413214B2 - Manufacturing method and manufacturing apparatus for liquid crystal display device - Google Patents

Description

  The present invention relates to a manufacturing method and a manufacturing apparatus for a liquid crystal display device.

  The liquid crystal display device includes first and second substrates and liquid crystal inserted between these substrates. For example, one of the first and second substrates is a TFT substrate on which TFTs are formed, and the other substrate is a color filter substrate on which color filters are formed. A peripheral seal made of a photocurable sealant is formed on the first substrate, and the peripheral seal is cured by irradiating with ultraviolet rays after the first and second substrates are bonded together. The liquid crystal is inserted into the area surrounded by the peripheral seal.

  In the conventional method for manufacturing a liquid crystal display device, an injection hole is provided in the peripheral seal, and after the first and second substrates are bonded together, the liquid crystal is injected from the injection hole provided in the peripheral seal in the vacuum chamber. . Thereafter, the injection hole of the peripheral seal is closed, the liquid crystal panel composed of the first and second substrates is taken out of the vacuum chamber, and the peripheral seal is pressurized so as to form an appropriate cell gap. The peripheral seal is cured by irradiation with ultraviolet rays.

Patent Document 1 and Patent Document 2 disclose a method of manufacturing a liquid crystal display device called a dropping injection method. In the dropping injection method, a peripheral seal is formed on a first substrate and liquid crystal is dropped. Then, the first substrate and the second substrate are bonded together by applying pressure in a vacuum chamber. Then, the pressurization of the first substrate and the second substrate is released, and the first substrate and the second substrate are released to the atmosphere. The peripheral seal is cured by irradiation with ultraviolet rays. According to the dropping injection method, the manufacturing process is shortened, and the manufacturing cost of the liquid crystal display device can be reduced.
JP-A-8-190099 JP 2000-66163 A

  In the dropping injection method, the first substrate and the second substrate are pressed and bonded in a vacuum chamber. Therefore, the first substrate and the second substrate are supported in the vacuum chamber by the respective support members. These supporting members are called an upper surface plate and a lower surface plate, and the first substrate on which the liquid crystal is dropped is fixed to the lower surface plate, and the second substrate is fixed to the upper surface plate. The upper surface plate is movable, and the first substrate and the second substrate can be pressed and bonded in a vacuum chamber by moving the upper surface plate toward the lower surface plate.

  The first substrate and the second substrate are respectively fixed to the upper surface plate and the lower surface plate by an electrostatic chuck. The electrostatic chuck is generally used as a substrate holding means in a semiconductor manufacturing process. However, the electrostatic chuck may not have sufficient adsorption force to attract a glass substrate used as a substrate of a liquid crystal display device. For example, if the surface of the glass substrate is not in close contact with the surface of the electrostatic chuck, the electrostatic chuck may not sufficiently hold the glass substrate. Thus, attempts have been made to sufficiently hold the glass substrate on the upper and lower surface plates by using both electrostatic chucking and vacuum suction.

  When both electrostatic chucking holding and vacuum chucking holding are used together, pressurize and bond the first substrate and the second substrate in a vacuum, and then move the upper platen away from the lower platen in the vacuum chamber. Move to release pressure and then open the vacuum chamber to atmosphere. However, in this case, when the pressure applied to the substrate is released in a vacuum, the peripheral seal is changed from the compressed state to the extended state by releasing the compression force, and the shape of the peripheral seal becomes uneven. There was a problem that a liquid crystal leak or a gap defect occurred.

  The objective of this invention is providing the manufacturing method and manufacturing apparatus of a liquid crystal display device which can hold | maintain a board | substrate appropriately at the time of bonding of a board | substrate.

  An apparatus for manufacturing a liquid crystal display device according to the present invention includes a first substrate, a second substrate, a liquid crystal inserted between the first substrate and the second substrate, and the first and second substrates surrounding the liquid crystal. An apparatus for manufacturing a liquid crystal display device having a seal provided between substrates, wherein a liquid crystal is dropped into a chamber into which a vacuum and atmospheric pressure can be introduced, and a region defined by the seal in the chamber. A first support member for supporting the first substrate; a second support member for supporting the second substrate in the chamber; the first support member and the second support member; An electrostatic chuck for fixing one of the first substrate and the second substrate to the one support member, a vacuum suction passage provided in the electrostatic chuck, and the vacuum Supply vacuum to adsorption passage It includes a vacuum suction line, and a circulation line connecting the can flow and the interior of the vacuum suction passage and the chamber that.

  In one embodiment, a groove is provided in the periphery of the surface of the electrostatic chuck so as to straddle the edge of the corresponding substrate. In one embodiment, the groove is provided on three or more sides. In one embodiment, the distribution line is connected to a vacuum suction line.

  According to the above configuration, after the first substrate and the second substrate are pressed and bonded together in a vacuum chamber, the chamber is brought to the atmosphere while the first substrate and the second substrate are pressed. Since it is opened, the pressure applied to the substrate can be released at atmospheric pressure, and the shape of the peripheral seal does not become uneven.

  According to the present invention, a liquid crystal display device can be reliably and inexpensively manufactured by a dropping injection method.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a perspective view showing one substrate of a liquid crystal display device of one embodiment, and FIG. 2 is a schematic cross-sectional view of the liquid crystal display device including the substrate of FIG.

  In FIG. 2, the liquid crystal display device 10 includes first and second substrates 12 and 14, a liquid crystal 16 inserted between the first and second substrates 12 and 14, and a first liquid crystal 16 so as to surround the liquid crystal 16. And a seal (peripheral seal) 18 provided between the second substrates 12 and 14. The liquid crystal display device 10 is an active matrix liquid crystal display device. One substrate is a TFT substrate on which TFTs are formed, and the other substrate is a color filter substrate on which color filters are formed. The liquid crystal display device 10 is manufactured by a dropping injection method.

  In FIG. 1, the liquid crystal 16 is dropped on the second substrate 14 from the dispenser 20 in the form of droplets. The dispenser 20 drops the liquid crystal 16 in a region surrounded by the peripheral seal 18 while moving as indicated by an arrow in FIG. The sealing agent that forms the peripheral seal 18 is made of a UV curable adhesive resin or an adhesive resin that is cured by the combined use of UV and heat. Such a sealant is applied to the second substrate 14 and cured later. An adhesive spacer obtained by coating the spacer with an adhesive is applied to the first substrate 12. It is also possible to provide a support instead of a space and omit the space spraying process.

  FIG. 3 is a cross-sectional view showing a method and apparatus for manufacturing a liquid crystal display according to the present invention. 4 is a cross-sectional view showing the manufacturing apparatus of FIG. 3 in a state where the upper housing of FIG. 3 is moved toward the lower housing, and FIG. 5 is a diagram in a state where the upper surface plate of FIG. 4 is moved toward the lower surface plate. It is sectional drawing which shows the manufacturing apparatus of 4.

  3 to 5, the liquid crystal display manufacturing apparatus 22 includes a chamber 24. The chamber 24 includes a movable upper housing 26 and a fixed lower housing 28. The packing 30 is disposed between the upper housing 26 and the lower housing 28, and the interior 32 of the chamber 24 becomes a sealed space.

  The chamber 24 has a vacuum passage 36 connected to a vacuum pump 34 for introducing a vacuum, and a purge passage 40 for introducing atmospheric pressure. A valve 38 is disposed in the vacuum passage 36 and a valve 42 is disposed in the purge passage 40. The purge passage 40 introduces an inert gas such as nitrogen into the chamber 24.

  The lower surface plate 44 is provided in the lower housing 28, the peripheral seal 18 is formed, and supports the second substrate 14 on which the liquid crystal 16 is dropped in a region defined by the peripheral seal 18. The lower surface plate 44 includes an electrostatic chuck 46, and the electrostatic chuck 46 has a vacuum suction passage 48. The electrostatic chuck 46 has a known electrode (not shown), and the second substrate 14 disposed on the electrostatic chuck 46 is fixed by an electrostatic force generated by energizing the electrode. The vacuum suction passage 48 opens to the surface of the electrostatic chuck 46, and fixes the second substrate 14 disposed on the electrostatic chuck 46 by a vacuum force supplied from a vacuum source.

  The upper surface plate 50 is movably provided on the upper housing 26 and supports the first substrate 12. The upper surface plate 50 includes an electrostatic chuck 52, and the electrostatic chuck 52 has a vacuum suction passage 54. The electrostatic chuck 52 has a known electrode (not shown), and the first substrate 12 disposed under the electrostatic chuck 52 is fixed by an electrostatic force generated by energizing the electrode. The vacuum suction passage 54 opens to the surface of the electrostatic chuck 52, and fixes the second substrate 14 disposed under the electrostatic chuck 52 by a vacuum force supplied from a vacuum source.

  Further, the vacuum suction line 56 is connected to the vacuum suction passage 48 of the electrostatic chuck 46 of the lower surface plate 44 and supplies a vacuum to the vacuum suction passage 48. The vacuum suction line 56 has a valve 58. A vacuum suction line 56 extends through the interior 32 of the chamber 24. A vacuum suction line 60 is connected to the vacuum suction passage 54 of the electrostatic chuck 52 of the upper surface plate 50 and supplies a vacuum to the vacuum suction passage 54. The vacuum suction line 60 has a valve 62. A vacuum suction line 60 extends through the interior 32 of the chamber 24.

  Further, the same pressure line 64 is connected to the vacuum suction line 56 on the downstream side of the valve 58 of the vacuum suction line 56 and is connected to the inside 32 of the chamber 24. The same pressure line 64 has a valve 66. The same pressure line 68 is connected to the vacuum suction line 60 on the downstream side of the valve 62 of the vacuum suction line 60 and to the inside 32 of the chamber 24. The same pressure line 68 has a valve 70.

  In FIG. 3, the movable upper housing 26 is separated from the lower housing 28 and the chamber 24 is open. In this state, the first and second substrates 12 and 14 are attached to the electrostatic chuck 52 of the upper surface plate 50 and the electrostatic chuck 46 of the lower surface plate 44, respectively. At this time, the valves 58 and 62 of the vacuum suction lines 56 and 60 are both opened, and the valves 66 and 70 of the same pressure lines 64 and 68 are closed.

  A vacuum is introduced into the vacuum suction passages 48 and 54 of the electrostatic chucks 46 and 52, and the first and second substrates 12 and 14 are tightly attracted to the electrostatic chucks 46 and 52, respectively, by the vacuum suction force. At the same time or thereafter, an electric current is applied to the electrodes of the vacuum chucks 46 and 52, and the first and second substrates 12 and 14 are attracted to the electrostatic chucks 46 and 52 by electrostatic attraction force. When there is no vacuum suction force, the action of the electrostatic suction force is weakened if the surfaces of the first and second substrates 12 and 14 are not flat. The first and second substrates 12 and 14 are securely held by the electrostatic chucks 46 and 52.

  In FIG. 4, the movable upper housing 26 is pressed against the lower housing 28 and the chamber 24 is closed. After the first and second substrates 12 and 14 are electrostatically attracted to the electrostatic chucks 46 and 52, or when the state shown in FIG. 4 is reached, the valves 58 and 62 of the vacuum suction lines 56 and 60 are both closed. The valves 66 and 70 of the same pressure lines 64 and 68 are opened. Thus, the pressure or vacuum in the interior 32 of the chamber 24 does not escape to the outside through the vacuum suction lines 56, 60, and the vacuum suction passages 48, 54 of the electrostatic chucks 46, 52 and the interior 32 of the chamber 24 Are connected to each other so that fluid can flow therethrough, and these portions have the same pressure. After the first and second substrates 12 and 14 are electrostatically attracted to the electrostatic chucks 46 and 52, even if the pressure in the vacuum suction passages 48 and 54 of the electrostatic chucks 46 and 52 decreases, the first and second substrates The two substrates 12 and 14 are securely held by the electrostatic chucks 46 and 52 by the electrostatic attraction force.

  Here, the valve 38 of the vacuum passage 36 is opened, and a vacuum is introduced into the interior 32 of the chamber 24. For example, the interior 32 of the chamber 24 is evacuated to about 1 Pa. This vacuum acts on the surfaces of the first and second substrates 12 and 14 and is also introduced into the vacuum suction passages 48 and 54 of the electrostatic chucks 46 and 52 through the same pressure lines 64 and 68. Therefore, the first and second substrates 12 and 14 are applied to the electrostatic chucks 46 and 52 by electrostatic attraction force in the state where the same vacuum pressure is applied to the upper and lower sides of the first and second substrates 12 and 14. Retained. If the same pressure lines 64 and 68 are not provided, the vacuum introduced into the interior 32 of the chamber 24 from the vacuum passage 36 acts strongly on the surfaces of the first and second substrates 12 and 14, and electrostatic adsorption force. As a result, a phenomenon was observed in which the first and second substrates 12 and 14 were detached from the electrostatic chucks 46 and 52.

  Next, in FIG. 5, the upper surface plate 50 is moved relative to the upper housing 26 and is moved toward the lower surface plate 44. The first substrate 12 is pressed toward the second substrate 14, the surface of the first substrate 12 contacts the peripheral seal 18 of the second substrate 14, and the spacer of the first substrate 12 is the second substrate. 14 contacts. After first performing rough bonding, fine bonding is performed while pressing the upper surface plate 50 toward the lower surface plate 44 at a pressure of about 10 to 500 kg.

  When the peripheral seal 18 is compressed and the cell gap between the first substrate 12 and the second substrate 14 is appropriate, the movement toward the lower surface plate 44 of the upper surface plate 50 is stopped. In this way, the first substrate 12 and the second substrate 14 are bonded together in a vacuum, and the liquid crystal 16 in the form of droplets is added to the second substrate 14 so that air does not enter the liquid crystal 16 therebetween. It spreads along the surface.

  When the bonding of the first substrate 12 and the second substrate 14 is completed, the energization to the electrostatic chuck 52 is stopped and the pressurization of the first substrate 12 and the second substrate 14 is maintained. The valve 42 of the purge passage 40 is opened. An inert gas such as nitrogen is introduced into the chamber 24 through the purge passage 40 and the chamber 24 is opened to the atmosphere. At this time, the valve 70 of the same pressure line 68 is opened, and the valve 66 of the same pressure line 64 is closed. However, the valves 66 and 70 of the same pressure lines 64 and 68 can be both opened.

  The inert gas acts on the surfaces of the first and second substrates 12 and 14 and is also introduced into the vacuum suction passage 54 of the electrostatic chuck 52 through the same pressure line 68. A vacuum acts on the vacuum suction passage 54 of the electrostatic chuck 52. Further, the energization to the electrostatic chuck 46 is stopped.

  Therefore, the upper surface plate 50 is moved away from the lower surface plate 44. Since the same body pressure is acting on the upper side and the lower side of the first substrate 12 via the same pressure lines 64 and 68, the electrostatic chuck 52 that rises together with the upper surface plate 50 smoothly moves from the first substrate 12. You can leave. If a vacuum is applied to the upper side of the first substrate 12, the first substrate 12 may be pulled by the electrostatic chuck 52, resulting in poor bonding. Since the valve 66 of the same pressure line 64 is closed while the upper surface plate 50 is raised, a vacuum acts on the lower side of the second substrate 14, and the second substrate 14 (that is, the liquid crystal panel) It is held by the electrostatic chuck 46 of the lower surface plate 44.

  When the movement of the upper surface plate 50 is completed, the valve 66 of the same pressure line 64 is opened. Then, the upper housing 26 is moved away from the lower housing 28, and the chamber 24 is opened. Thereafter, the peripheral seal 18 is irradiated with ultraviolet rays to cure the peripheral seal 18.

  Note that, as described above, when the chamber 24 is in a vacuum state after the bonding of the first substrate 12 and the second substrate 14 is completed, the first substrate 12 and the second substrate 14 When the pressure is released, the shape of the peripheral seal 18 becomes non-uniform, and there is a problem that liquid crystal leaks or a gap defect occurs. FIG. 6 is a view showing an example of the peripheral seal 18 in this case. Ends A and B of the peripheral seal 18 are normal, but an intermediate portion C of the peripheral seal 18 is in a state in which the peripheral seal 18 is in a compressed state. The part which became thin locally is seen. In the present invention, the pressure on the first substrate 12 and the second substrate 14 is maintained, the pressure is returned to the atmospheric pressure, and the pressure is released in the state of the atmospheric pressure. Can be prevented.

  FIG. 7 is a diagram showing an example of another example of the electrostatic chuck. A groove 72 is provided on the periphery of the surface of the electrostatic chuck 52 so as to straddle the end of the corresponding first substrate 12. In FIG. 7, the grooves 72 are formed in rows in a direction perpendicular to the sides of the square electrostatic chuck 52 and parallel to the sides of the electrostatic chuck 52. By so doing, it is possible to eliminate an air pocket between the electrostatic chuck 52 and the first substrate 12 during evacuation. In addition, since an inert gas enters between the electrostatic chuck 52 and the first substrate 12 at the time of purging (releasing to the atmosphere), the separation of the first substrate 12 from the electrostatic chuck 52 can be assisted.

  As described above, according to the present invention, the liquid crystal display device can be reliably and inexpensively manufactured by the dropping injection method.

It is a perspective view which shows one board | substrate of the liquid crystal display device of one Example. It is a schematic sectional drawing of the liquid crystal display device containing the board | substrate of FIG. It is sectional drawing which shows the manufacturing method and manufacturing apparatus of the liquid crystal display device by this invention. FIG. 4 is a cross-sectional view showing the manufacturing apparatus of FIG. 3 in a state where the upper housing of FIG. 3 is moved toward the lower housing. It is sectional drawing which shows the manufacturing apparatus of FIG. 4 in the state which moved the upper surface plate of FIG. 4 toward the lower surface plate. It is a figure which shows the example of the periphery seal | sticker in which the shape became non-uniform | heterogenous. It is a figure which shows the example of the electrostatic chuck of another example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Liquid crystal display device 12, 14 Board | substrate 16 Liquid crystal 18 Peripheral seal 22 Manufacturing apparatus 24 Chamber 36 Vacuum passage 38 Purge passage 44 Lower surface plate 46 Electrostatic chuck 48 Vacuum adsorption passage 50 Upper surface plate 52 Electrostatic chuck 54 Vacuum adsorption passage 56 Vacuum adsorption Line 60 Vacuum suction line 64 Same pressure line 68 Same pressure line 72 Groove

Claims (4)

A first and second substrate; a liquid crystal inserted between the first and second substrates; and a seal provided between the first and second substrates so as to surround the liquid crystal. An apparatus for manufacturing a liquid crystal display device,
A chamber capable of introducing vacuum and atmospheric pressure;
A first support member for supporting a first substrate in which liquid crystal is dropped in an area defined by a seal in the chamber;
A second support member for supporting the second substrate in the chamber;
An electrostatic chuck provided on at least one of the first support member and the second support member for fixing one of the first substrate and the second substrate to the one support member, and the static A vacuum suction passage provided in the electric chuck;
A vacuum suction line for supplying a vacuum to the vacuum suction passage;
An apparatus for manufacturing a liquid crystal display device, comprising: a distribution line that connects the vacuum suction passage and the inside of the chamber so as to allow distribution. Wherein the peripheral portion of the surface of the electrostatic chuck, Ru Tei groove is provided so as to straddle the edge of the corresponding substrate, an apparatus for manufacturing a liquid crystal display device according to claim 1. The groove Ru Tei provided in three or more sides, an apparatus for manufacturing a liquid crystal display device according to claim 2. The flow line is connected to the vacuum suction line, an apparatus for manufacturing a liquid crystal display device according to claim 1.

Images