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  Apparatus and method for fabricating bonded substrateUSPTO Application #: 20060037707Title: Apparatus and method for fabricating bonded substrate Abstract: A bonded-substrate fabricating apparatus capable of reducing defective bonded substrates fabricated. A transfer robot sucks the outer edge area of the bottom surface of a substrate and spouts gas toward the bottom surface of the substrate to carry the substrate into a vacuum process chamber of a press machine while keeping the substrate horizontally. A press plate holds the substrate, which is held by the transfer robot, by suction. (end of abstract) Agent: Staas & Halsey LLP - Washington, DC, US Inventors: Takanori Muramoto, Takuya Ohno, Tsukasa Adachi, Koji Hashizume, Yosimasa Miyajima, Takao Kojima USPTO Applicaton #: 20060037707 - Class: 156382000 (USPTO) The Patent Description & Claims data below is from USPTO Patent Application 20060037707. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a divisional of application Ser. No. 10/347,625, filed Jan. 22, 2003, now pending. [0002] This application is based upon and claims the priority of Japanese application no. 2002-076173, filed Mar. 19, 2002, and U.S. patent application Ser. No. 10/347,625, filed Jan. 22, 2003, the contents being incorporated herein by reference. BACKGROUND OF THE INVENTION [0003] The present invention relates to an apparatus and method for fabricating bonded substrate (panel). More particularly, the present invention relates to an apparatus and method for fabricating bonded substrate for a liquid crystal display (LCD), which is provided by bonding two substrates at a predetermined gap. [0004] Nowadays, there are demands for large and thin liquid crystal display (LCD) panels capable of providing fine display on a large display area, and apparatus which fabricates such LCD panels have been developed. An LCD panel is fabricated by arranging two glass substrates to face each other at an extremely narrow gap (several micrometers) and filling a liquid crystal between the two glass substrates. The two glass substrates are, for example, an array substrate on which a plurality of TFTs (Thin Film Transistors) are formed in a matrix form and a color filter substrate on which color filters (red, green and blue), a light shielding film, etc. are formed. The light shielding film contributes to improving contrast and shields light toward the TFTs to prevent generation of an optical leak current. The array substrate is bonded to the color filter substrate by a sealing material (adhesive) containing a thermosetting resin. [0005] A method of fabricating an LCD panel includes a liquid crystal sealing step of sealing a liquid crystal between two glass substrates. The conventional liquid crystal sealing step is carried out by the following vacuum injection method. First, the TFT-formed array substrate is bonded to the color filter substrate (opposing substrate) via a sealing material. The sealing material is cured. The bonded substrates and a liquid crystal are placed in a vacuum tank and an inlet port provided in the sealing material is dipped in the liquid crystal. The pressure in the tank is set back to the atmospheric pressure so that the liquid crystal is sucked from the inlet port Finally, the inlet port of the sealing material is sealed. [0006] Recently, attention has been paid to the following dropping method instead of the vacuum injection method. First, the frame of a sealing material is formed in such a way as to enclose the outer periphery of the array substrate. A predetermined dose of a liquid crystal is dropped on the surface of the array substrate within the frame of the sealing material. Finally, the array substrate is bonded to the color filter substrate in vacuum. The dropping method can reduce the amount of a liquid crystal in use significantly and can shorten the time needed for the liquid crystal sealing step, thus resulting in a reduction in panel fabrication cost. It is therefore expected that mass production will be improved. [0007] A bonded-substrate fabricating apparatus which operates according to the dropping method has the following problems. [0008] 1. Improper Chuck Originated from the Bending of Substrate [0009] Normally, a substrate is held by suction by vacuum chuck or chucking by electrostatic chuck. In the vacuum-chuck holding, a holding plate which can hold a substrate by vacuum suction is used. The array substrate is held by the holding plate and the frame of the sealing material is formed on the array substrate. The adequate amount of a liquid crystal is dropped on the surface of the array substrate from a dispenser. Finally, the array substrate is bonded to the color filter substrate in a vacuum atmosphere. [0010] In the electrostatic-chuck holding, a holding plate which has an electrode is used. A voltage is applied between the electrode of the holding plate and a conductive film formed on a glass substrate to generate Coulomb's force between the glass and the electrode. The Coulomb's force electrostatically holds the glass substrate on the holding plate. [0011] In the vacuum-chuck holding, when the degree of vacuum in the process chamber becomes as high as a certain level, vacuum chuck does not work. In this respect, the substrate is electrostatically held by electrostatic chuck before suction by vacuum chuck stops working. [0012] Normally, two substrates are separately held by an upper holding plate and a lower holding plate and are bonded together. Specifically, to prevent transfer of dust on the bonded surfaces or contamination thereof, the outer edge areas (portions outward of the frame of the sealing material) of the substrates are held by a transfer robot and are moved into the process chamber. However, the large and thin substrates are likely to curve (bend) due to their dead loads. The holding plates cannot stably hold the bent substrates. If the process chamber is depressurized for the purpose of bonding the substrates, therefore, the misalignment of the substrates or separation of the substrates from the holding plates may occur. [0013] In a case where the holding plate (electrostatic chuck) electrostatically holds a bent substrate, glow discharge occurs during depressurization of the process chamber. This case brings about a problem such that a circuit or TFT devices formed on the substrate are damaged, resulting in generation of defects. In addition, as air remains between the holding plate and the substrate, the substrate may be released tom the electrostatic chuck while depressurizing the process chamber. [0014] 2. Improper Bonding Originated from the Bending of Substrate [0015] In the bonding step, two substrates are pressed while keeping a predetermined substrate gap. The important factors in the bonding step are to keep the two substrates parallel to each other and to press the two substrates with a uniform load. If the substrates are bent, however, the frame of the sealing material is pressed unevenly in the bonding step, so that the liquid crystal may be pushed out of the frame of the sealing material. If the pressing pressure is uneven, the pressing pressure needed to seal the liquid crystal increases so that the influence on the substrates becomes greater. This makes it difficult to fabricate stable products. [0016] 3. Dust Oriented Improper Chuck [0017] The holding plates that hold the two substrates separately have chuck surfaces which are planarized at a high precision. In a case where dust or glass pieces are adhered to the chuck surfaces, the dust is transferred onto the substrates, causing the misalignment of the substrates or separation of the substrates from the holding plates. As minute dust is adhered to the holding plates by electrostatic force, however, it is difficult to remove the dust from the holding plates. [0018] 4. Defects Originated from Variation in Cell Thickness [0019] It is necessary to properly adjust the amount of a liquid crystal to be sealed in an extremely narrow substrate gap (cell thickness). The gap between the two substrates is determined by placing spacers between the substrates or forming poles on one of the substrates. However, the spacers and poles have a slight height variation. This results in a change in the substrate gap, so that the amount of the liquid crystal sealed may become too much or too little locally. This would bring about a problem such that the cell thickness would vary after the substrates were bonded. The variation in cell thickness cause uneven display of the LCD panel. SUMMARY OF THE INVENTION [0020] Accordingly, it is an objective of the present invention to provide a bonded-substrate fabricating apparatus and fabricating method which can suppress fabrication of defective bonded substrates. [0021] To achieve the above object the present invention provides an apparatus for fabricating a bonded substrate by bonding a first substrate and a second substrate, each of the first substrate and the second substrate having an inner surface to be bonded and an outer surface opposite to the inner surface. The apparatus includes a first holding plate for holding the first substrate, a second holding plate arranged to face the first holding plate for holding the second substrate by chucking the outer surface of the second holding plate, and a transfer machine which transfers the first and second substrates to the first and second holding plates respectively and includes a holding member for holding the second substrate horizontally by chucking the second substrate and spouting gas onto the inner surface of the second substrate. Continue reading... Full patent description for Apparatus and method for fabricating bonded substrate Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Apparatus and method for fabricating bonded substrate patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Apparatus and method for fabricating bonded substrate or other areas of interest. ### Previous Patent Application: Beverage bottle labeling apparatus configured to label beverage bottles in a beverage bottling plant Next Patent Application: Method for pressure bonding of a breaker-tread assembly with a carcass assembly by means of stitching in the manufacture of green tyres and device for accomplishment of such method Industry Class: Adhesive bonding and miscellaneous chemical manufacture ### FreshPatents.com Support Thank you for viewing the Apparatus and method for fabricating bonded substrate patent info. IP-related news and info Results in 0.3635 seconds Other interesting Feshpatents.com categories: Computers: Graphics , I/O , Processors , Dyn. Storage , Static Storage , Printers |
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