LINEAR DEPOSITION APPARATUS FOR FORMING

ORGANIC THIN LAYER Technical Field [1] The present invention relates to a linear deposition apparatus suitable for mass production of organic light emitting diode (OLED) devices and linear transfer units thereof to enable the linear transfer of a substrate and a metal mask. Background Art [2] Currently used representative methods, for mass production of organic light emitting diode (hereinafter referred to as OLED) devices, include a substrate UV cleaning process, heating process, cooling process, organic matter deposition process, plasma etching process, metal thin-film process, substrate transfer process, substrate stacking process, a process of supplying and removing a substrate, and a metal mask deposition process. To perform the above enumerated processes, there have been used apparatuses designed such that a plurality of vacuum chambers or containers are connected to one another to supply or remove a substrate and metal mask. In general, an ink-jet printing process that is performed at atmospheric pressure and other methods have been conventionally used in the use of high-molecular weight organic matter, but, in the case of deposition apparatuses for mass production of low-molecular weight organic thin film devices, a vacuum deposition method, that utilizes one or more vacuum chambers to keep a high vacuum degree, has been most widely used. Disclosure of Invention Technical Problem [3] The prior art as described above provides a polygonal cluster-type deposition apparatus for the mass production of OLED devices in which a plurality of OLED device process vacuum chambers are circularly arranged around and connected to a single polygonal substrate transfer chamber. A large-scale vacuum robot is located within the substrate transfer chamber to transfer a substrate, especially, a large-area substrate, to the respective process chambers under operation of robot arms. During a substrate deposition process in a selected one of the process chambers, the robot transfers another substrate into another selected one of the process chambers to perform a mass production process of OLED devices. In the prior art deposition apparatus, however, the plurality of process chambers are densely arranged, making it difficult to gain a space required for the operation of the respective process chambers as well as the repair and maintenance thereof. Moreover, if the size of the process chamber increases or the polygonal shape of the apparatus is complicated due to an increase in the total number of the process chambers, the vacuum robot should have lengthy arms. Such lengthy arms tend to droop at their distal end portions, thereby causing poor accuracy in the transfer of a substrate, and also restrict a weight range of the substrate to be transferred thereby. As a result, in the case of a metal mask process, the lengthy arms have a difficulty to transfer a heavy metal mask, causing a dete¬ rioration in the mass production efficiency of OLED devices. Such a difficulty is worsened, especially, in a deposition process of large-area OLED devices. Technical Solution [4] The present invention has been made in view of the above mentioned problems, and an aspect of the present invention is to provide a linear deposition apparatus for the mass production of OLED devices and transfer units thereof, the linear deposition apparatus comprising a plurality of OLED device process chambers 10, a plurality of substrate transfer chambers 40, a plurality of small-scale vacuum robots 60, a plurality of substrate transfer units 50 and metal mask transfer units 70, a plurality of gate valves 30, an upper linear rail 90, and a lower linear rail 80, thereby being capable of simultaneously transferring a plurality of substrates horizontally along the substrate transfer chambers 40 as well as vertically from the substrate transfer chambers 40 to the OLED device process chambers 10 to simultaneously perform several different processes, such as OLED device deposition, cleaning, etc. The linear deposition apparatus of the present invention is easy to gain a space required for the repair and maintenance thereof, and especially, has the effect of considerably enhancing the pro¬ ductivity of large-area OLED devices. Brief Description of the Drawings [5] The above aspect, and other features and advantages of the exemplary embodiments of the present invention will become more apparent after reading the following detailed description when taken in conjunction with the drawings, in which: [6] FIG. 1 is a schematic diagram of deposition process chambers for the production of organic thin film devices consistent with the prior art; [7] FIG. 2 is a schematic diagram of a linear deposition apparatus for the mass production of organic thin film devices consistent with the present invention; [8] FIG. 3a is a schematic diagram illustrating a linear transfer unit, for use in the transfer of organic thin film device substrates, consistent with the present invention; [9] FIG. 3b is a schematic diagram similar to FIG. 3a, illustrating a displaced state of the linear transfer unit; [10] FIG. 4 is a schematic diagram of a metal mask transfer unit consistent the present invention; [11] FIG. 5 is an enlarged schematic sectional view illustrating the interior configuration of a substrate transfer chamber consistent with the present invention; [12] FlG. 6 is an enlarged diagram of the substrate transfer unit consistent with an exemplary embodiment of the present invention; and [13] FlG. 7 is an enlarged diagram of the metal mask transfer unit consistent with an exemplary embodiment of the present invention. Best Mode for Carrying Out the Invention [14] As described above, the present invention provides a linear deposition apparatus for the mass production of OLED devices and linear transfer units thereof, the linear deposition apparatus comprising a plurality of OLED device process chambers 10, a plurality of substrate transfer chambers 40, vacuum robot containers 41 provided at the respective substrate transfer chambers 40, a plurality of small-scale vacuum robots 60, a plurality of substrate transfer units 50 and metal mask transfer units 70, an upper linear rail 90, and a lower linear rail 80, and a plurality of gate valves 30 interposed between the OLED device process chambers 10 and the substrate transfer chambers 40. [15] An exemplary embodiment of the present invention will now be described in detail with reference to the annexed drawings. [16] FIG. 1 is a schematic diagram illustrating the arrangement of deposition process chambers for the mass production of OLED devices consistent with the prior art. Referring to FIG. 1, a plurality of OLED device process chambers 10 are circularly arranged around a single substrate transfer chamber 11 and connected thereto by in¬ terposing gate valves 30, respectively, thereby constructing a polygonal, so-called "cluster type", deposition apparatus for the mass production of organic devices. The cluster type mass production apparatus allows a substrate 35 to be transferred to the respective process chambers 10 under the operation of a large-scale vacuum robot 20 contained in the substrate transfer chamber 11. During a substrate deposition process performed in a selected one of the process chambers, the robot 20 is also able to transfer another substrate into another selected one of the process chambers to perform a certain process. In this manner, the deposition apparatus of the prior art can simul¬ taneously perform several processes of a plurality of substrates. [17] However, in the above described deposition apparatus of the prior art, the plurality of process chambers are densely arranged, making it difficult to gain a space required for the operation of the respective process chambers and the repair and maintenance thereof. Moreover, if the size of the process chamber increases or the polygonal shape of the apparatus is complicated, the vacuum robot should have lengthy arms. Such lengthy arms restrict a weight range of an object, i.e. substrate, to be transferred thereby. For example, in the case of a metal mask process, the lengthy arms have a difficulty to transfer a heavy metal mask, deteriorating the mass production efficiency of organic devices. Such a difficulty is worsened, especially, in a deposition process of large-area OLED devices. [18] FIG. 2 is a schematic diagram of a linear deposition apparatus for the mass production of OLED devices consistent with an exemplary embodiment of the present invention. The linear deposition apparatus of the present invention is designed to hor¬ izontally and linearly transfer a substrate in order to continuously perform several deposition processes for the mass production of OLED devices, and is easy to gain a space therearound to facilitate the repair and maintenance thereof. Referring to FIG. 2, the linear deposition apparatus consistent with the exemplary embodiment of the present invention is configured in such a manner that a plurality of rectangular box- shaped substrate transfer chambers 40 are linearly connected to one another in an interior communicatable manner and have vacuum robot containers 41 protruding downward therefrom, respectively. The respective substrate transfer chambers 40 are connected to respective OLED device process chambers 10 by interposing the vacuum robot containers 41 and gate valves 30 therebetween. In the exemplary embodiment of the present invention, the process chambers 10 and the gate valves 30 of the linear deposition apparatus are similar to those of the prior art and thus are designated by the same reference numerals as those of the prior art. The gate valves 30 serve to prevent the substrate transfer chambers 40 from being contaminated by organic matter, etc. during an OLED device deposition process, and to continuously maintain a high vacuum degree inside the substrate transfer chambers 40 even if the process chambers 10 are released from a vacuum state for the repair and maintenance of the apparatus. [19] With such a configuration, a plurality of substrates are able to be transferred hor¬ izontally and linearly through the interior of the aligned substrate transfer chambers 40 under operation of transfer units and also transferred vertically between the substrate transfer chambers 40 and the OLED device process chambers 10 under operation of small-scale robots. Thereby, the substrates undergo various processes, for example, deposition, cleaning, etc. for the mass production of OLED devices. Differently from the prior art cluster type mass production apparatus, the deposition apparatus of the present invention has a linear structure, referred to as an "in-line cross type" structure. This structure is advantageous to gain a space for the operation and repair of the apparatus, and especially, advantageous to considerably enhance the productivity of OLED devices having a large area (730mm in width and 920mm in length). [20] FIG. 3a is a schematic diagram illustrating the interior configuration of the linear deposition apparatus for the mass production of OLED devices. Referring to FIG. 3a, the vacuum robot containers 41 contain small-scale vacuum robots 60, respectively. The vacuum robots 60 transmit substrates 35 from the process chambers 10 to substrate transfer units 50 located in the rectangular box-shaped substrate transfer chambers 40. Each of the substrate transfer units 50 has a pair of U-shaped substrate grippers, which are provided at opposite ends of the transfer unit 50 and connected to each other by means of a linear connector, and is coupled to a linear rail 90 located in an upper region of the substrate transfer chambers 40 to horizontally move along the linear rail 90. Thereby, each of the substrate transfer units 50 is able to linearly and horizontally transfer two substrates at a time by using the substrate grippers. In the exemplary embodiment of the present invention, a plurality of the substrate transfer units 50 are provided to simultaneously transfer a plurality of substrates for the mass production of OLED devices. In this case, a respective one of the substrate transfer units 50 reciprocates in only three adjacent process chambers 10 to simultaneously transfer two substrates from two process chambers 10 to the connected adjacent two process chambers 10. After the plurality of substrates are processed in the respective process chambers 10, the substrates are simultaneously shifted to the vacuum robots 60, respectively, to be transferred to the associated process chambers 10. [21] The vacuum robots 60 function to simply transfer the substrates vertically by a relatively short distance and thus have short arms. The short arms are effective to con¬ siderably enhance their loading capacity, i.e. the weight of an object to be transferred thereby. The number of the process chambers 10 and the number of the connected substrate transfer chambers 40 are adjustable in consideration of the number of processes to be performed for the mass production of OLED devices. In the mass production of OLED devices, it is generally the case that the respective process chambers perform different processes from one another in order to minimize in¬ terference between the different processes. Alternatively, certain OLED device research equipment may often perform several processes in a single process chamber at a time. [22] FIG. 3b is similar to FIG. 3a, but illustrating a state wherein a substrate, which was processed in a first process chamber 12, is transferred to an entrance of a second process chamber 13 by means of a first substrate transfer unit 55. The substrate, disposed on the first substrate transfer unit 55, is vertically shifted to the second process chamber 13 by means of the small-scale vacuum robot 60. After that, the first substrate transfer unit 55 is returned to its original position to ready the transfer of the next substrate. In the exemplary embodiment of the present invention as stated above, the first substrate transfer unit 55 has the two substrate grippers at opposite ends thereof. Thereby, both the grippers of the first substrate transfer unit 55 are able to si¬ multaneously transfer two substrates, which were processed in the first process chamber 12 and the second process chamber 13, to the second process chamber 13 and a third process chamber 14. In this manner, the first substrate transfer unit 55 re- ciprocates in the first to third process chambers 12 to 14, and an adjacent second substrate transfer unit 56 reciprocates in the third to fifth process chambers. [23] FlG. 4 illustrates a U-shaped metal mask transfer unit 70 located under the substrate transfer units 50 in the linearly aligned substrate transfer chambers 40. The metal mask transfer unit 70 is coupled to a linear rail 80 located in a lower region of the substrate transfer chambers 40 to horizontally move along the linear rail 80 to transfer a metal mask 71 into a selected one of the process chambers 10. In the exemplary embodiment of the present invention, the small-scale vacuum robots 60 are adjustable in their vertical height. Thereby, the vacuum robots 60 receive the metal mask 71 from the metal mask transfer unit 70 at their lowered position to transfer the metal mask 71 from the substrate transfer chamber 40 to the process chamber 10. [24] The metal mask transfer unit 70 serves to remove a damaged substrate from the apparatus, thereby facilitating the repair and maintenance of the apparatus, and also serves to return a specific substrate into the previous process chamber for the repetition of a specific process. [25] FlG. 5 is an enlarged sectional view illustrating the substrate transfer unit 50, the metal mask transfer unit 70 and the small-scale vacuum robot 60 mounted in the substrate transfer chamber 40. To prevent collision between the robot arm and the metal mask transfer unit 70 when the robot 60 separates a substrate from the substrate transfer unit 50, a height adjustor 61 is mounted at an upper end of the robot arm to adjust a height of an end effecter 62 from the robot arm. The small-scale vacuum robot 60 is vertically movable to adjust a height of its body from the bottom of the robot container 41. A height of the end effecter 62, connected to the end of the robot arm, is adjusted to assist the robot 60 to separate the metal mask or substrate from the metal mask transfer unit 70 located in the lower region of the substrate transfer chamber 40 or the substrate transfer unit 50 located in the upper region of the substrate transfer chamber 40. [26] FlG. 6 is an enlarged view of the substrate transfer unit 50. In an exemplary embodiment of the present invention, the substrate transfer unit 50 has a pair of U- shaped substrate grippers 52 connected to each other by means of a center connector 53. A respective one of the U-shaped substrate grippers 52 centrally defines a substrate seating recess 51 in an upper region thereof to achieve safe or stable substrate transfer without a shaking risk. [27] FlG. 7 is an enlarged diagram of the U-shaped metal mask unit 70. Similar to the U- shaped substrate gripper 52, the metal mask unit 70 also centrally defines a metal mask seating recess 72 to achieve safe or stable transfer of the metal mask 71 without a shaking risk. [28] Although the exemplary embodiment of the invention have been disclosed for il- lustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and sprit of the invention as disclosed in the accompanying drawings. Industrial Applicability [29] As apparent from the above description, the present invention provides a linear deposition apparatus for mass production of OLED devices, which can horizontally transfer a plurality of substrates within substrate transfer chambers thereof in a horizontal direction as well as can vertically transfer the substrates between the substrate transfer chambers and OLED device process chambers, thereby being capable of simultaneously performing several different processes, such as OLED device deposition, cleaning, etc. The linear deposition apparatus consistent with the present invention is easy to gain a space required for the repair and maintenance of the apparatus. Especially, in the case of the mass production of large-area substrates (730mm in width and 920mm in length) and super large-area substrates (2000mm in width and length), the present invention achieves a considerably enhanced mass pro¬ ductivity as compared to the prior art. [30] [31]