Patent Abstract:
A laser irradiation apparatus is disclosed. In one embodiment, the apparatus includes i) an X-axis location control board configured to move a plurality of drivers in an X-axis direction and ii) a plurality of output heads cooperatively arranged with the drivers and configured to move with movement of the drivers, wherein the output heads are configured to receive laser beams. The apparatus may further include a Z-axis location control board cooperatively arranged with the X-axis location control board and configured to move the X-axis location control board in an Z-axis direction, wherein the output heads alternatively protrude with different lengths along an Y-axis direction.

Full Description:
RELATED APPLICATION 
       [0001]    This application claims priority to and the benefit of Korean Patent Application No. 10-2010-0090614 filed in the Korean Intellectual Property Office on Sep. 15, 2010, the entire contents of which are incorporated herein by reference. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    The described technology generally relates to a laser irradiation apparatus and a sealing method of an organic light emitting display element using the same. 
         [0004]    2. Description of the Related Technology 
         [0005]    In general, an organic light emitting display element is most widely used among organic semiconductor elements, and has a relatively simple structure. The organic display element is self-emissive unlike a liquid crystal display (LCD), and thus it does not require an additional back light so that an organic light emitting diode (OLED) display has advantages of a slim thickness and a reduced weight. Thus, recently, the OLED display has been actively developed as a display panel of portable data terminals such as mobile computers, portable cellular phones, portable game devices, electronic books. 
       SUMMARY 
       [0006]    One aspect is a laser irradiation apparatus that can shorten a sealing process time of the organic light emitting display element and a sealing method of the organic display element using the same. 
         [0007]    Another aspect is a laser irradiation apparatus that can easily correspond to variation of a cell size of an organic light emitting display element by arranging output heads of the laser irradiation apparatus in a zigzag form, and a sealing method of the organic display element using the same. 
         [0008]    Another aspect is a laser irradiation apparatus which includes: an X-axis location control board configured to move a plurality of drivers in an X-axis direction; a plurality of output heads cooperatively arranged with the drivers and configured to move with movement of the drivers, wherein the output heads are configured to receive laser beams; and a Z-axis location control board cooperatively arranged with the X-axis location control board and configured to move the X-axis location control board in an Z-axis direction. The output heads alternatively protrude with different lengths along an Y-axis direction. 
         [0009]    The output heads are arranged in a zigzag form in the X-axis location control board along the Y-axis direction. 
         [0010]    The drivers and the output heads may be respectively connected with each other by brackets, and the brackets may protrude toward the Y-axis direction with different lengths for each alternation corresponding to the plurality of output heads. 
         [0011]    The brackets and the drivers may be fixed by a holder assembly. The holder assembly may include a first holder connected to the bracket and a second holder combined to the first holder and fixing the output heads. 
         [0012]    The first holder may be mounted in the shape of a plate extended along the Z-axis direction, and one side thereof may be connected with the bracket and the second holder may be mounted on the other side. 
         [0013]    The second holder may protrude to the first holder and a penetration hole may be formed in the second holder for insertion fixing of the output heads. 
         [0014]    Another aspect is a sealing method of an organic light emitting diode (OLED) display which includes: (a) providing a first substrate including a pixel area where an organic electric field light emitting element is formed and a non-pixel area; (b) providing a second substrate attached on one area including the pixel area of the first substrate; (c) forming frits arranged in a plurality of rows and columns along the periphery area of the second substrate corresponding to the non-pixel area of the first substrate; (d) forming a sealant in the second substrate of an external side of the frit; (e) attaching the first and second substrates to each other and hardening the sealant; (e) attaching the first and second substrates to each other and hardening the sealant; (g) applying the laser beam to the next row of the frit by changing a direction to a vertical direction of the frit when laser beam irradiation to the row direction of the frit in step of (f) is terminated. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a diagram of a laser irradiation apparatus according to an embodiment. 
           [0016]      FIG. 2  schematically shows an output head portion of  FIG. 1  in the mounted state. 
           [0017]      FIG. 3  shows a protruded state of the output head portion of  FIG. 1  to a length direction of a bracket. 
           [0018]      FIG. 4  is a flowchart of a sealing method of an organic light emitting diode (OLED) display according to an embodiment. 
           [0019]      FIG. 5  shows a laser beam irradiation to organic light emitting display elements arranged in a plurality of rows and a plurality of columns. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    When moisture or oxygen is introduced into an organic light emitting element, the life span of the element is reduced due to oxidation or exfoliation of an electrode material, light efficiency is deteriorated, and color fidelity degrades. 
         [0021]    Therefore, a sealing treatment is typically performed to isolate an element and prevent moisture from being introduced in the organic light emitting display element in the manufacturing process. For sealing treatment of the display element, a sealing method that coats a frit on a glass substrate is used. 
         [0022]    When the display element is sealed using the frit, the frit is coated on a sealing portion of each of the organic display elements, a laser beam is irradiated to the sealing portion of the element using an output head of a laser irradiation apparatus, and then the frit is hardened. 
         [0023]    Here, when the cell size of the display element is increased, output heads of the laser irradiation apparatus should maintain a large gap therebetween corresponding to the cell size. 
         [0024]    However, the output heads of the laser irradiation apparatus are arranged in one line and thus interference may be generated when the gap between the output heads is increased more than a predetermined distance, and therefore it is difficult to increase the gap between the output heads greater than a predetermined distance. Accordingly, when the cell size of the organic light emitting display element becomes greater than a predetermined size, the hardening of the frit using the laser irradiation apparatus cannot be smoothly performed. 
         [0025]    Hereinafter, embodiments will be described with reference to the accompanied drawings. As those skilled in the art would realize, the described embodiments may be modified in various different ways. 
         [0026]    In addition, the size and thickness of each component shown in the drawings may be arbitrarily shown for understanding and ease of description. In the drawings, the thickness of layers, films, panels, regions, etc. may be exaggerated for clarity. 
         [0027]      FIG. 1  schematically shows a laser irradiation apparatus according to an embodiment. 
         [0028]    Hereinafter, the present embodiment is applied to a sealing process of an organic light emitting diode (OLED) display, but it may be applied to other display devices that use sealing of a plurality of glass plates. 
         [0029]    As shown in  FIG. 1 , a plurality of organic light emitting display elements  17  are disposed on a first substrate  11  and a second substrate  13 . In addition, a sealing member  15  seals the first and second substrates  11  and  13  to prevent foreign particles from being introduced into the display elements  17 . In one embodiment, the sealing member  15  is doped with one or more transition metal and thus an absorption characteristic with respect to a specific wavelength is enforced so that it can be easily softened. In the present embodiment, the sealing member  15  may be formed with a frit. Hereinafter, the sealing member and the frit use the same reference numeral  15 . 
         [0030]    A plurality of output heads  30  are disposed on the substrates  11  and  13  to irradiate laser beams to the sealing member  15  such that the first substrate  11  and the second substrate  13  are sealed. Hereinafter, a configuration of the laser irradiation apparatus  100  according to the embodiment will be described in further detail. 
         [0031]    As shown in  FIG. 1 , the laser irradiation apparatus  100  includes an X-axis location control board  20  on which a plurality of driving units  10  are slidably mounted, the output heads  30  coupled to the driving units  10  and slid with movement of the driving units  10  and to which laser beams are irradiated, and a Z-axis location control board  21  coupled with the X-axis location control board  20  and moving the X-axis location control board  20  to the Z-axis direction. 
         [0032]    The X-axis location control board  20  is formed extending along the X-axis direction, and enables the driver  10  to move a length direction thereof. In addition, the Z-axis location control board  21  is coupled to the X-axis location control board  20  using a ball screw. The Z-axis location control board  21  controls a location of the X-axis location control board  20 , and the plurality of output heads  30  are substantially simultaneously focused such that laser beams with substantially uniform density can be irradiated. 
         [0033]      FIG. 2  shows the output heads of  FIG. 1  in the mounted state. 
         [0034]    As shown in  FIG. 2 , the output head  30  receives an output for irradiation of a laser beam  31   a  through a laser oscillation unit  31  and irradiates the laser beam  31   a.    
         [0035]    Hereinafter, irradiation of the laser beam  31   a  through the output head  30  will be described in further detail. 
         [0036]    The laser beam  31   a  is irradiated from the laser oscillation unit  31 . 
         [0037]    In addition, the irradiated laser beam  31   a  is incident on flexible channels  33 . The flexible channels  33  refer to beam path members, and the laser beam  31   a  is input to one end and output operation is performed through the other end. In one embodiment, the laser beam  31   a  is passed through a plurality of lenses (not shown) before being incident on the flexible channels  33  to make the laser beam  31   a  enter to the flexible channel  33  by substantially uniforming the density of the laser beam  31   a . The laser beam  31   a  output from the flexible channel  33  is finally irradiated in the output head  30 . 
         [0038]    The output head  30  irradiates the laser beam  31   a  to a region to which the substrates  11  and  13  of the OLED display are to be sealed. A condenser lens  35  is mounted on the output head  30  so that the laser beam  31   a  output from the flexible channels  33  can be substantially uniformly condensed. For this, the condenser lens  35  may include a convex lens. The output heads  30  can be movably mounted on the X-axis location control board  20 . 
         [0039]    Combination of the output head  30  and the X-axis location control board  20  will now be described in further detail. 
         [0040]    In one embodiment, the driver  10  is sildably mounted on the X-axis location control board  20  by motor driving. In one embodiment, the driver  10  is mounted as a linear motor for movement on the X-axis location control board  20  without vibration. The driver  10  can be individually driven for distance control between the output heads  30 . In addition, a holder assembly  50  is connected to the driver  10  using brackets  40  and  40   a.    
         [0041]      FIG. 3  shows the output head of  FIG. 1  in the protruding state along a length change of the bracket. 
         [0042]    As shown in  FIG. 2  and  FIG. 3 , the holder assembly  50  includes a first holder  51  connected with the brackets  40  and  40   a  and a second holder  53  coupled to the first holder  51  and fixing the output head  30 . The first holder  51  is directly connected to the brackets  40  and  40   a  forms a plate shape. The second holder  53  is mounted on the first holder  51  and fixes the output head  30 . In one embodiment, the second holder  53  includes a penetration hole (not shown) and the condenser lens  35  is inserted to the penetration hole such that the output head  30  can be fixed. 
         [0043]    Protruded lengths of the holder assemblies  50  in the respective drivers  10  may be different from each other through the length adjustment of the brackets  40  and  40   a . In one embodiment, as shown in  FIG. 1 , the length of an even-numbered bracket  40   a  among the brackets  40  and  40   a  is longer by a predetermined length than that of an odd-numbered bracket  40 . In this embodiment, an even-numbered output head  30  protrudes further to the Y-axis direction than an odd-numbered output head  30  among the output heads  30 . In one embodiment, as shown in  FIG. 1 , the output heads  30  are disposed in a substantially zigzag form. As the output heads  30  are arranged in the zigzag form, the distance between the output heads  30  may be freely set. That is, when the output heads  30  are disposed in one line as in a typical alignment, interference is generated between adjacent output heads  30  so that a gap greater than a predetermined distance cannot be maintained therebetween. However, as in the present embodiment, the distance between the output heads  30  can be easily controlled when the output heads  30  are arranged in substantially the zigzag form. Thus, the distance between the output heads  30  can be controlled substantially corresponding to the size of a cell in the organic light emitting display element so that the sealing time of the substrates  11  and  13  can be shortened, thereby shortening a manufacturing time of the OLED display. 
         [0044]      FIG. 4  is a flowchart of a sealing method of an organic light emitting diode (OLED) display according to an embodiment, and  FIG. 5  schematically shows irradiation of a laser beam to organic light emitting display elements arranged in a plurality of rows and a plurality of columns. 
         [0045]    Referring to  FIG. 4  and  FIG. 5 , a sealing method of the OLED display will now be described in further detail. 
         [0046]    First, a first substrate  11  including a pixel area where an organic light emitting element  17  is formed and a non-pixel area is provided (S 10 ). The pixel area is a portion where a display screen is displayed, and the non-pixel area is all the portions excluding the pixel area. 
         [0047]    Next, a second substrate  13  attached on an area including the pixel area is provided (S 20 ). Here, the first substrate  11  is a lower substrate and the second substrate  13  is an upper substrate. 
         [0048]    Frits  15  arranged in a plurality of rows and columns are formed along a periphery area of the second substrate  13  substantially corresponding to the non-pixel area of the first substrate  11  (S 30 ). The frits  15  prevent foreign particles from being introduced into the organic light emitting display element  17 . 
         [0049]    A sealant is formed in the second substrate  13  at an external side of the frit  15  (S 40 ). 
         [0050]    Next, the first substrate  11  and the second substrate  13  are attached to each other and the sealant is hardened (S 50 ). 
         [0051]    Subsequently, a plurality of output heads  30  of a laser irradiation apparatus  100  are arranged in a substantially zigzag direction corresponding to the frits  15  in step of S 30 , and a laser beam is irradiated to the row direction of the frit  15  (S 60 ). 
         [0052]    Step S 60  will be described in further detail with reference to  FIG. 5 . In  FIG. 5 , organic light emitting display elements  17  are arranged in a plurality of rows and a plurality of columns in the substrates  11  and  13 . 
         [0053]    First, the output heads  30  of the laser irradiation apparatus  100 , arranged in the substantially zigzag shape are placed corresponding to the organic light emitting display elements of  FIG. 5 , arranged in the rows and columns. 
         [0054]    The output heads  30  of the laser irradiation apparatus  100  move along the row direction and irradiate laser beams to the frits of the organic light emitting display elements. Here, since the output heads  30  are arranged in the substantially zigzag direction according to the present embodiment, locations of the output heads  30  can be smoothly controlled without generating interference between the output heads  30  when controlling distances between the output heads  30  corresponding to the size of the organic light emitting display element. 
         [0055]    When the irradiation of the laser beam to the row direction of the frit  15  is terminated (S 60 ), the laser beam is irradiated to the next row of the frit  15  by changing the irradiation direction to a substantially vertical direction of the frit  15  (S 70 ). Accordingly, a laser beam  31   a  can be irradiated to the frit  15  without an influence depending on the size of a cell of the organic light emitting display element so that a manufacturing time of the OLED display can be shortened. In the above-stated embodiments, the output heads  30  can move and irradiate the laser beam to the frits  15  while the substrates  11  and  13  are fixed, and the substrates  11  and  13  can move and the laser beam  31   a  can be irradiated to the frits  15  while the output heads  30  are fixed. When the substrates  11  and  13  are moving, a stage (not shown) for the movement may be mounted on a lower portion of the substrates  11  and  13 . 
         [0056]    According to at least one of the disclosed embodiments, the output heads of the laser irradiation apparatus are arranged in a substantially zigzag form so that the gap between the output heads can be controlled without an interference of the output heads, and accordingly hardening of the frit can be smoothly performed corresponding to a cell size of the organic light emitting display element. 
         [0057]    Embodiments have been described with reference to the accompanied drawings. It is to be understood that the disclosed embodiments are not considered limiting, and are intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Technology Classification (CPC): 1