Patent Document

BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a plasma display panel, and more particularly, to a plasma display panel, apparatus for fabricating the same, and fabrication process thereof.  
           [0003]    2. Background of the Related Art  
           [0004]    This is the age of multimedia, which requires a display enabling to give expression to colors almost the same of the nature as well as fine and large image. For a wide display over 40 inches, it is difficult to introduce the present CRT cathode ray tube) and LCD(liquid crystal display) structures. Instead, a plasma display panel attracts public attention in a field of a next generation display.  
           [0005]    Such a plasma display panel, as shown in FIG. 1A, is constructed with upper and lower plates  10  and  20  confronting and combined each other. FIG. 1B shows a cross-sectional structure of the plasma display panel in FIG. 1A, in which a face of the lower plate  20  is rotated by 90□ for the convenience of explanation.  
           [0006]    The upper plate  10  is constructed with scan electrodes  16  and  16 ′ and sustain electrodes  17  and  17 ′ which are parallel each other, a dielectric layer  11  formed on the upper plate  10  including the scan electrodes  16  and  16 ′ and sustain electrodes  17  and  17 ′, and a passivation layer  12  on the dielectric layer  11 . And, the lower plate  20  is constructed with address electrodes  22 , a dielectric body layer  21  formed on an a front face of the plate including the address electrodes  22 , partition walls  23  formed on the dielectric body layer  21  between the address electrodes  22 , and a fluorescence material  24  formed on surfaces of the partition walls and dielectric body layers  21  in the respective discharge cells. And, mixed inert gas such as He, Xe and the like fills up a space between the upper and lower plates  10  and  20  so as to form a discharge area.  
           [0007]    Operation of the above-constructed plasma display panel follows.  
           [0008]    First, when a driving voltage is applied thereto, a confronting discharge occurs between the address and scan electrodes, whereby portions of electrons discharged from the inert gas in the discharge cells collide with a surface of the passivation layer. Subsequently, secondary electrons are discharged from the surface of the passivation layer by the collision of the electrons. Then, the discharged secondary electrons collide with plasma gas so as to spread the discharge. After the confronting discharge between the address and scan electrodes finishes, wall charges having opposite polarities are generated from the surface of the passivation layer on the address and scan electrodes.  
           [0009]    When the driving voltage being applied to the address electrodes is cut off while the discharge voltage having opposite polarities is continuously applied to the scan and sustain electrodes, plane discharge occurs in the discharge area of the surfaces of the dielectric layer and passivation layer by a potential difference between the scan and sustain electrodes. Such confronting and plane discharges make the electrons in the discharge cell collide with the inert gas in the discharge cell. As a result of this, the inert gas in the discharge cell becomes excited and produces an ultraviolet ray having a wave of 147 nm in the discharge cell. Such an ultraviolet ray collides with the fluorescence material surrounding the address electrode, thereby realizing an image.  
           [0010]    In order to make the plasma display panel exhibit its performance and elongate its durability, the layers inside the panel should be built solid and no impurity gas except the discharge gas should exist.  
           [0011]    A process of fabricating such a plasma display panel may be divided into three parts such as a former process, a latter process, and a module process.  
           [0012]    First, the former process is a process of forming various layers on the upper and lower plates  10  and  20 . The latter process includes combination of the upper and lower plates  10  and  20 , exhaust, discharge gas injection and tip-off, aging, and inspection. In this case, the tip-off is a process comprising the steps of completing the exhaust and discharge gas injection through an exhaust pipe and cutting and sealing the exhaust pipe. And, the aging is a process for removing impurities finally by driving electrodes for a predetermined time by applying a voltage thereto so as to attain a discharge voltage drop.  
           [0013]    Finally, the module process is the last process of mounting circuits and assembling parts so as to complete a plasma display panel.  
           [0014]    An apparatus for fabricating a plasma display panel and a method of fabricating a plasma display panel according to a related are explained as follows by referring to the attached drawings.  
           [0015]    FIG. 2  illustrates a latter process for a plasma display panel and a process condition thereof according to a related art, FIGS. 3A to FIGS. 3C illustrate layouts for explaining a combining process in FIG. 2, FIG. 4 illustrates a cross-sectional view of an exhaust pipe, FIG. 5 illustrates a layout of a combination/exhaust separate type apparatus for a display panel according to a related art, and FIG. 6 illustrates a cart structure in FIG. 5.  
           [0016]    The latter process for a plasma display panel (hereinafter abbreviated PDP) according to related art, as shown in FIG. 2, includes combination of the upper and lower plates  10  and  20 , exhaust, discharge gas injection and tip-off, aging, and inspection.  
           [0017]    First, the upper and lower plates  10  and  20  are transferred to a combination apparatus. And, an edge of the upper plate  10 , as shown in FIG. 3A, is coated with a sealing material  31 , i.e. frit, to the uniform thickness using a dispenser. In this case, the frit consists of glass, SiO 2 , and an additive for improving adhesiveness.  
           [0018]    And, they are dried at about 120° and thermally treated at a high temperature over 400° C. in order to remove impurities remaining in the frit.  
           [0019]    Then, the thermally-treated upper and lower plates are transferred to a combination apparatus. In this case, the upper plate  10  is transferred to the combination apparatus by being exposed to the atmosphere.  
           [0020]    AS shown in FIG. 3B, the upper and lower plates  10  and  20  are aligned to each other in the combination apparatus. And, the upper and lower plates  10  and  20  are fixed by combination clamps  32 . Then, the upper and lower plates  10  and  20 , as shown in FIG. 3C, are combined with each other by melting the frit.  
           [0021]    When carrying out the combination process, an exhaust pipe  40  consisting of a long-straw type glass is attached to an exhaust hole  42  of the lower plate  20  using a frit ring.  
           [0022]    Then, a panel of which combination is finished is transferred to an exhaust and gas injection apparatus.  
           [0023]    The exhaust and gas injection apparatus carries out an exhaust process exhausting impurities sticking to a layer and impurity gas generated from the layer outside using the exhaust pipe  40  formed in the combination process.  
           [0024]    Then, discharge gas is injected through the exhaust pipe  40 . And, a tip of the exhaust pipe  40  is tipped off by applying a heat thereto, thereby preventing the leakage of the injected discharge gas.  
           [0025]    Subsequently, the process is completed by inspecting a state of the panel after the aging.  
           [0026]    Thus, a separate type fabrication apparatus, which carries out the combination and the exhaust and gas injection separately in exhaust pipe type fabrication apparatuses, is divided into the combination apparatus and the exhaust and gas injection apparatus. The exhaust and gas injection apparatus, as shown in FIG. 5, includes a hot-wind heating furnace  51  to establish an exhaust and discharge gas injection condition and a cart  52  loading a panel and unloading the panel on which the exhaust and discharge gas injection has been carried out in the hot-wind heating furnace  51 .  
           [0027]    The cart  52 , as shown in FIG. 6, is constructed complicatedly with a vacuum pump  61  to make vacuum inside the panel, a vacuum pipe system including an exhaust manifold  62 , valves and pipes, a bombe  65  for discharge gas injection, a gas injection pipe system including a gas injection manifold  63 , valves and pipes, and a tip-off unit  64  to tip off the exhaust pipe  40 .  
           [0028]    Unfortunately, the above-constructed pipe type PDP fabrication apparatus and fabrication process thereof contains the following problems.  
           [0029]    First, impurity gas in a gap between the upper and low plates, which are combined with each other and leave an interval of several microns, of the panel over 40 inches wide has to be sucked through a long and narrow exhaust pipe, which takes at least several hours in a high vacuum state of 10 −7  Torr. Thus, the bottleneck of a product process is resulted. Therefore, the number of apparatuses increases for mass production, thereby failing to avoid increasing a space for the apparatuses.  
           [0030]    Second, an intense heat is applied thereto in a high vacuum state, which carries a massive load on the panel. And, the panel is formed of glass vulnerable to heat deviation and pulling intensity, thereby failing to avoid panel damage or panel characteristic degradation.  
           [0031]    Third, the exhaust pipe also made of glass may be broken by an impact on transference or temperature variance on exhaust, whereby automation of the panel fabrication is hardly achieved.  
           [0032]    Fourth, the plastic process is carried out to remove the impurities of the frit. Yet, energy loss is increased due to heating and cooling of the plastic process. And, a great deal of impurities is generated again from the frit due to the high heat applied thereto during the combination process. Thus, the exhaust time is increased and the frit fragile to external impact may cause the panel breakage due to the external impact.  
           [0033]    Fifth, the passivation layer of the upper plate is formed to play an important role for the prevention of the damage on the electrodes during discharge. But, the passivation layer exposed to the atmosphere is transferred to the combination process and then the exhaust and discharge gas injection process is carried out. ‘Mg’ widely used as a material for the passivation layer is easy to be contaminated by being combined with the atmospheric components such as H 20  and the like. Therefore, degradation of product performance and reduction of product durability are brought about.  
           [0034]    Sixth, an intense heat is applied thereto in the high vacuum state on combining the upper and lower plates so as to carry a massive load on the panel formed of glass vulnerable to heat deviation and pulling intensity, thereby failing to avoid panel damage or panel characteristic degradation.  
           [0035]    Seventh, the plastic process is carried out to remove the impurities of the frit. Yet, energy loss is increased due to heating and cooling of the plastic process. And, a great deal of impurities is generated again from the frit due to the high heat applied thereto during the combination process. Thus, the exhaust time is increased and the frit fragile to external impact may cause the panel breakage due to the external impact.  
           [0036]    Besides, in order to overcome the above problems, proposed are a tip-less process using no exhaust pipe and a semi-tip-less process injecting discharge gas through an additional hole instead of filling in the chamber with discharge gas. However, theses processes fail to prevent the generation of impurity gas penetrating into the panel, thereby causing the discharge gas contamination which is the fatal defect of the no-pipe process. Thus, both of the tip-less and semi-tip-less fail to be applied to the product production practically.  
         SUMMARY OF THE INVENTION  
         [0037]    Accordingly, the present invention is directed to a plasma display panel, apparatus for fabricating the same, and fabrication process thereof that substantially obviates one or more problems due to limitations and disadvantages of the related art.  
           [0038]    An object of the present invention is to provide a plasma display panel, apparatus for fabricating the same, and fabrication process thereof enables to reduce the time for a product process and prevent panel characteristic reduction and panel damage by preventing the generation of impurity gas and achieving the plates-combination at a room temperature.  
           [0039]    Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.  
           [0040]    To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, an apparatus for fabricating a plasma display panel according to the present invention includes a passivation layer formation means for forming a MgO passivation layer on a first substrate, a substrate transfer means for receiving the first substrate from the passivation layer formation means, the substrate transfer means transferring the received first substrate and a second substrate inserted therein to a next fabrication stage, a cleaning means for removing impurities existing on the first or second substrate transferred through the substrate transfer means, a sealing material coating means for coating a sealing material on the first substrate transferred through the cleaning means, and a discharge gas injection/combination means for injecting discharge gas inside, the discharge gas injection/combination means for aligning precisely the first substrate transferred through the sealing material coating means and the second substrate with each other using an alignment robot, the discharge gas injection/combination means for combining the first and second substrates with each other.  
           [0041]    In another aspect of the present invention, a process for fabricating a plasma display panel using an ultraviolet ray producing means according to the present invention includes the steps of coating a predetermined area of a first substrate with a sealing material having elasticity and hardened by ultraviolet rays, aligning a second substrate with the first substrate, and combining/attaching the first and second substrates with/to each other by applying the ultraviolet rays to the sealing material with the ultraviolet ray producing means.  
           [0042]    In a further aspect of the present invention, a plasma display panel includes a first substrate, a sealing material coated on a predetermined area of an effective image circumference of the first substrate, the sealing material having predetermined width and height, a second substrate aligned over the first substrate, the second substrate adhering closely to a surface of the sealing material, and a plurality of pressurization means for applying a predetermined pressure so as to maintain a combination/attachment state between the first and second substrates, the pressurization means mounted along the circumference of the first substrate and a circumference of the second substrate with a predetermined interval therebetween.  
           [0043]    It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0044]    The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:  
         [0045]    [0045]FIG. 1A and FIG. 1B illustrate bird&#39;s-eye and cross-sectional views of a general plasma display, respectively  
         [0046]    FIG. 2  illustrates a latter process for a plasma display panel and a process condition thereof according to a related art;  
         [0047]    [0047]FIGS. 3A to FIGS. 3C illustrate layouts for explaining a combining process in FIG. 2;  
         [0048]    [0048]FIG. 4 illustrates a cross-sectional view of an exhaust pipe;  
         [0049]    [0049]FIG. 5 illustrates a layout of a combination/exhaust separate type apparatus for a display panel according to a related art;  
         [0050]    [0050]FIG. 6 illustrates a cart structure in FIG. 5;  
         [0051]    [0051]FIG. 7 illustrates a construction of a fabrication apparatus for PDP according to the present invention;  
         [0052]    [0052]FIG. 8 illustrates a PDP fabrication process and process conditions thereof according to the present invention;  
         [0053]    [0053]FIG. 9A and FIG. 9B illustrate a PDP combination process according to a first embodiment of the present invention;  
         [0054]    [0054]FIG. 10A and FIG. 10B illustrate a PDP combination process according to a second embodiment of the present invention;  
         [0055]    [0055]FIG. 11A and FIG. 11B illustrate a PDP combination process according to a third embodiment of the present invention;  
         [0056]    [0056]FIG. 12A and FIG. 12D illustrate a PDP combination process according to a fourth embodiment of the present invention; and  
         [0057]    [0057]FIG. 13A and FIG. 13C illustrate a PDP combination process according to a first embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0058]    Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.  
         [0059]    [0059]FIG. 7 illustrates a construction of a PDP fabrication apparatus according to the present invention.  
         [0060]    A PDP fabrication apparatus according to the present invention, as shown in FIG. 7, is constructed with an upper plate passivation layer formation chamber  71  to form a MgO passivation layer on an upper plate  100 , a substrate transfer chamber  72  constructed with two stories and transferring the upper plate  100  received from the upper plate passivation layer formation chamber  71  and a lower plate  120  inserted therein without being exposed to the atmosphere to a next fabrication apparatus, a pre-alignment chamber  73  carrying out temporary alignment to combine the upper and lower plates with each other transferred through the substrate transfer chamber  72  using a first alignment robot, a cleaning chamber  74  removing impurities existing in the upper and lower plates  100  and  120  aligned by the pre-alignment chamber  73  and carrying out vacuum exhaust, a sealing material coating chamber  75  coating the upper plate  100  with a sealing material, a discharge gas injection/combination and discharge gas refinement chamber  76  injecting discharge gas in a chamber, carrying out precision alignment on the upper and lower plates  100  and  120  using a second alignment robot, combining the upper and lower plates  100  and  120 , recovering the discharge gas inside after finishing the combination and refining the recovered discharge gas, and a panel unloading chamber  77  unloading a finished panel and transferring the unloaded panel to a panel holder  78 .  
         [0061]    In this case, the present invention is an atmosphere-proof apparatus built in one body so as have the upper plate having the passiavtion layer not to be exposed to the atmosphere until the combination of the upper plate  100  is finished.  
         [0062]    The first and second alignment robots introduce a vision system used for a part handling industrial robot and the like which carry out image recognition and measurement/control on the upper and lower plates of the panel and align an object to a corresponding position in accordance with the result of the measurement.  
         [0063]    The discharge has injection/combination and discharge gas refinement chamber  76  is constructed with a discharge gas injection/combination unit  76 - 1  discharge gas is injected therein, aligning the upper and lower plates  100  and  120  using the second alignment robot, and combining the upper and lower plates  100  and  120  with each other and a discharge gas refinement unit  76 - 2  recovering the remaining discharge gas after the completion of the combination and extracting and storing the discharge gas having a wanted quality by removing impurities and refining the recovered discharge gas.  
         [0064]    A material enables to be used for the combination at a room temperature as the sealing material for combining the upper and lower plates  100  and  120  such as a material hardened by ultraviolet rays. Therefore, the present invention may have the discharge gas injection/combination unit  76 - 1  equipped with an ultraviolet ray producing means.  
         [0065]    The above-constructed PDP fabrication process according to the present invention is described as follows be referring to FIG. 8.  
         [0066]    Referring to FIG.8, a MgO passivation layer is formed on the upper plate  100  at a temperature of 200° C. at 10 −7  Torr in the upper plate passivation layer formation chamber  71 , which is then transferred to the substrate transfer chamber  72  without being exposed to the atmosphere.  
         [0067]    The substrate transfer chamber  72  receives the upper plate  100  having the passivation layer at the same state, i.e. at 200° C. and 10 −7  Torr, of the upper plate passivation layer formation chamber  71 . And, the lower plate  120  is inserted into the substrate transfer chamber  72 . Then, the upper and lower plates  100  and  120  are transferred to the pre-alignment chamber  73  by the substrate transfer chamber  72  without being exposed to the atmosphere.  
         [0068]    The pre-alignment chamber  73  carries out temporary alignment for the combination between the upper and lower plates  100  and  120  transferred from the substrate transfer chamber  72  using the first alignment robot having the vision system under the same condition as the substrate transfer chamber  72 .  
         [0069]    Subsequently, the temporarily-aligned upper and lower plates  100  and  120  are sent to the cleaning chamber  74  without being exposed to the atmosphere, and then undergo a cleaning process comprising four steps at a predetermined temperature and pressure condition(200° C. and a variable inner pressure) in the cleaning chamber  74 .  
         [0070]    First, impurity gas is primarily removed by an initial vacuum state, 10 −7  Torr, in the cleaning chamber  74 .  
         [0071]    Subsequently, the cleaned panel is coated with the sealing material enabling a room temperature combination/attachment in he sealing material coating chamber  75 . And, the combination/attachment between the upper and lower plates  100  and  120  are carried out at a room temperature in the discharge gas injection/combination unit  76 - 1 , in which discharge gas is injected, of the discharge gas injection/combination and discharge gas refinement chamber  76 .  
         [0072]    In this case, the sealing material for combination/attachment uses a material enabling the hardening and combination not by heat but by ultraviolet rays without producing impurities. Thus, the upper and lower plates  100  and  120  are combined/attached to each other by irradiating ultraviolet rays to the sealing material using the UV producing means at a room temperature.  
         [0073]    After the combination between the upper and lower plates  100  and  120  has been completed, the panel is transferred to the panel unloading chamber  77 .  
         [0074]    Then, the panel unloading chamber  77  transfers and mounts the panel to and on the panel holder  78 . In this case, the panel transfer to the panel holder  78  is carried out through a roller hearth.  
         [0075]    On the other hand, after the panel, which has undergone the discharge gas injection and combination in the discharge gas injection/combination unit  76 - 1  of the discharge gas injection/combination and discharge gas refinement chamber  76 , is transferred to the panel unloading chamber  77 , the discharge gas refinement unit  76 - 2  recovers the discharge gas remaining in the discharge gas injection/combination unit  76 - 1 , removes the impurities therein, and refines the recovered discharge gas so as to extract and store the discharge gas having a predetermined quality in a storage tank. Thus, the discharge gas is recycled for a next discharge gas injection.  
         [0076]    Reference will now be made in detail to first to fifth embodiments of sealing material coating and combination processes in the above-described PDP fabrication process according to the present invention, examples of which are illustrated in the accompanying drawings.  
         [0077]    [First Embodiment] 
         [0078]    In a first embodiment of the PDP combination process according to the present invention, as shown in FIG. 9A, an elastomer based sealing material  101  is coated on an effective image area circumference of the upper plate  100  to surround.  
         [0079]    In this case, the elastomer based sealing material  101  is a rubber different from the conventional sealing material such as the frit has a characteristic of being hardened by UV rays at a room temperature without being heated, and specifically, discharges no impurity gas in accordance with heating or pressurization, and has its own elasticity enough to reduce the external impact applied to the upper and lower plates  100  and  120 .  
         [0080]    Referring to FIG. 9B, after the lower plate  120  is aligned to the upper plate  100 , the sealing material  101  is hardened by being irradiated with UV rays using a UV producing apparatus(not shown in the drawing) so as to combine/attach the upper and lower plates  100  and  120  with/to each other.  
         [0081]    [Second Embodiment] 
         [0082]    In a second embodiment of the PDP combination process according to the present invention, as shown in FIG. 10A, an elastomer based sealing material  102  is coated on an effective image area circumference of the upper plate  100  to surround.  
         [0083]    In this case, the elastomer based sealing material  102 , despite having no adhesiveness, is a rubber different from the conventional sealing material such as the frit, produces no impurity gas in accordance with heating or pressurization, and has its own elasticity enough to reduce the external impact.  
         [0084]    Referring to FIG. 10B, after the lower plate  120  is aligned to the upper plate  100 , the upper and lower plates  100  and  120  are combined and attached each other using at least a pressurizing means such as a clip  103 .  
         [0085]    In this case, the clip  103  having a restoring force toward a direction of fastening the upper and lower plates  100  and  102  applies a predetermined pressure to the upper and lower plates  100  and  120  so as to seal up the upper and lower plates  100  and  102 .  
         [0086]    Moreover, the sealing material  102  having elasticity buffs the force of the clip  103  fastening the upper and lower plates  100  and  120  as well as the external impact.  
         [0087]    [Third Embodiment] 
         [0088]    In a third embodiment of the PDP combination process according to the present invention, as shown in FIG. 11A, an elastomer based sealing material  104  is coated on a circumference of an effective image area of the upper plate  100  to surround.  
         [0089]    In this case, the elastomer based sealing material  104 , despite having no adhesiveness, is a rubber different from the conventional sealing material such as the frit, produces no impurity gas in accordance with heating or pressurization, and has its own elasticity enough to reduce the external impact.  
         [0090]    And, a circumference of the sealing material  104  is coated with an adhesive agent  105  tending to coagulate at a room temperature.  
         [0091]    In this case, the adhesive agent  105  is a material enabling to coagulate immediately at a room temperature, pressurize the sealing material  104  inside, and endure compression/pulling forces.  
         [0092]    Referring to FIG. 11B, after the upper and lower plates  100  and  120  are aligned to each other precisely, the upper and lower plates  100  and  120  maintains to combined each other by applying a predetermined pressure thereto.  
         [0093]    Then, the compressed state of the upper and lower plates  100  and  120  are maintained as the adhesive agent  105  coagulates.  
         [0094]    [Fourth Embodiment] 
         [0095]    In a fourth embodiment of the PDP combination process according to the present invention, as shown in FIG. 12A, an elastomer based sealing material  106  is coated on a circumference of an effective image area of the upper plate  100  to surround and the sealing material  106  is also coated on a predetermined area of the lower plate  120  corresponding to the sealing material coated area of the upper plate  100 . And, an adhesive agent  107  is coated on the sealing material  106  coated on the upper plate  100 .  
         [0096]    In this case, the elastomer based sealing material  106 , despite having no adhesiveness, is a rubber different from the conventional sealing material such as the frit, produces no impurity gas in accordance with heating or pressurization, and has its own elasticity enough to endure the external impact. And, the adhesive agent  107  is a material enabling to coagulate immediately at a room temperature, pressurize the sealing material  106  outside, and endure compression/pulling forces.  
         [0097]    Referring to FIG. 12B, after the lower plate  120  is aligned to the upper plate  100 , the upper and lower plates  100  and  120  are combined and attached each other by applying a predetermined pressure thereto.  
         [0098]    Referring to FIG. 12C, a circumference of the sealing material  106  of the combined/attached upper and lower plates  100  and  120  is coated with a silicon or polymer based second sealing material  108  so as to carry out a second sealing process.  
         [0099]    [0099]FIG. 12D shows a cross-sectional view of the PDP bisected along a cutting line A-A′ in FIG. 12C so as to describe the structure according to the fourth embodiment of the present invention, in which the adhesive agent  107  is coated between the sealing material  106  and the second sealing material  108  is coated on the circumference of the sealing material  106 .  
         [0100]    [Fifth Embodiment] 
         [0101]    In a fifth embodiment of the PDP combination process according to the present invention, as shown in FIG. 13A, an elastomer based sealing material  109  is coated on a circumference of an effective image area of the upper plate  100  to surround. And, a frit  110  is coated on an area of the lower plate  120  corresponding to the area coated with the sealing material  109 . Then, a plasticizing process is carried out thereon.  
         [0102]    In this case, the elastomer based sealing material  109 , despite having no adhesiveness, is a rubber producing no impurity gas in accordance with heating or pressurization and has its own elasticity enough to reduce the external impact.  
         [0103]    Referring to FIG. 13B, the lower plate  120  is aligned to the upper plate  100 .  
         [0104]    Referring to FIG. 13C, the upper and lower plates  100  and  120  are combined and attached each other using at least a pressurizing means such as a clip  111 .  
         [0105]    In this case, the clip  111  having a restoring force toward a direction of fastening the upper and lower plates  100  and  102  applies a predetermined pressure to the upper and lower plates  100  and  120  so as to seal up the upper and lower plates  100  and  102  by the sealing material  109 .  
         [0106]    Moreover, the sealing material  109  having elasticity buffs the force of the clip  111  fastening the upper and lower plates  100  and  120  as well as the external impact.  
         [0107]    The above-described combination processes according to the first to fifth embodiment of the present invention are carried out at a room temperature, thereby requiring no cooling and heating processes after combining the upper and lower plates by melting the frit. Therefore, the present invention enables to prevent energy loss as well as reduce a process time.  
         [0108]    Using the elastomer based sealing material enabling a room-temperature combination/attachment produces no impurity gas, the present invention enables to produce a real product having no exhaust pipe, i.e. tip-less, by preventing the fatal discharge gas contamination of the ‘tip-less’. Nevertheless, using an exhaust pipe, the present invention enables to decrease the exhaust time by reducing the impurity gas content in the combined panel so as to be applied to the real product fabrication.  
         [0109]    Specifically, the present invention enables to overcome the discharge gas contamination fatal to the ‘tip-less’, thereby more preferable to be applied to the ‘tip-less’ system having such advantages as process equipment simplification, process time reduction and the like instead of the system using an exhaust pipe.  
         [0110]    Discharge gas is injected inside the panel in the system using an exhaust pipe after the combination/attachment, while the other combination/attachment is carried out in a chamber filled up with discharge gas in the ‘tip-less’ system. In both cases, the pressure inside the panel becomes about 500 Torr, which is lower than the atmospheric pressure. Therefore, the adhesiveness/combination force between the upper and lower plates  100  and  120  is more increased by both of the atmospheric pressure to which the upper and lower plates are exposed to after the fabrication and the combination processes according to the first to fifth embodiments of the present invention.  
         [0111]    Accordingly, a PDP fabrication process according to the present invention has the following advantages and effectiveness.  
         [0112]    First, the major processes are carried out in the equipments in one body which is isolated from external environment and maintains a vacuum state therein so as to block the generation or entrance of impurities. Thus, the MgO passivation layer of the upper plate is not exposed to the atmosphere so as to prevent the generation of impurity gas as well as minimize the time for exhausting the impurity gas. Therefore, the total fabrication process time is reduced to increase the product yield and the space for equipments is reduced.  
         [0113]    Second, the upper plate having the MgO passivation layer thereon is transferred to a next stage without being exposed to the atmosphere, thereby preventing the degradation of the panel characteristic due to the passivation contamination generated from the reaction between the MgO passivation layer and atmosphere.  
         [0114]    Third, impurities remaining in the panel are removed using a cleaning chamber, thereby preventing the degradation of the panel characteristic due to the remaining impurities after the fabrication of the panel.  
         [0115]    Fourth, the combination/attachment process is carried out at a room temperature, thereby enabling to prevent the degradation of the panel characteristic by the fewer burdens applied to the panel unlike the conventional high pressure/temperature condition.  
         [0116]    Fifth, the combination/attachment process is carried out at a room temperature, thereby enabling to minimize energy loss.  
         [0117]    Sixth, the combination/attachment process is carried out while maintaining the same state as discharge gas is injected, thereby enabling to prevent a panel damage caused by the breakage of an exhaust pipe unnecessary for the discharge gas injection.  
         [0118]    Seventh, the combination/attachment process is carried out at a room temperature, thereby enabling to prevent the degradation of the panel characteristic by the fewer burdens applied to the panel unlike the conventional high pressure/temperature condition.  
         [0119]    Eighth, the combination/attachment process is carried out at a room temperature, thereby enabling to minimize energy loss without the heating/cooling process required for the combination process using the conventional frit.  
         [0120]    Ninth, an elastomer based rubber instead of a glass based sealing material is used as a sealing material so as to be from impurity gas exhaustion, thereby enabling to prevent the degradation of the panel characteristic due to the discharge gas contamination.  
         [0121]    Tenth, an elastomer based rubber instead of a glass based sealing material is used as a sealing material, thereby enabling to prevent the panel damage, which is caused by an external shock, by elasticity of the sealing material.  
         [0122]    The forgoing embodiments are merely exemplary and are not to be construed as limiting the present invention. The present teachings can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art.

Technology Category: 5