Abstract:
A bonding apparatus bonds one member to another member by using the pressure difference between the pressure between the two members and the ambient pressure. After aligning two members close to each other on a chuck and a supporting member in a vacuum chamber, the chamber is vacuumed to form vacuum between the two members. Then, air is supplied to the vacuum chamber to increase the ambient pressure to normal. The increased ambient pressure pushes the one member on the supporting member to the other member on the chuck, bonding both members together.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims priority from and the benefit of Korean Patent Application No. 10-2014-0148128, filed on Oct. 29, 2014, which is hereby incorporated by reference for all purposes as if fully set forth herein. 
     BACKGROUND 
     1. Field of the Invention 
     The present invention relates to a bonding apparatus and a method for manufacturing a display device using the same. 
     2. Discussion of the Background 
     Various kinds of display devices, such as an organic light emitting display device and a liquid crystal display device, have been used in a computer, a portable terminal, and monitors of various kinds of information devices. 
     Such a display device may include a panel member, such as a display panel, for displaying an image and an optical member, such as an optical film, bonded to the display panel in an image emission direction to perform an optical function. The optical member may include an adhesive layer to be bonded to the panel member. 
     Conventionally, the optical member is bonded to the panel member by pressing using a roller or a drum. 
     SUMMARY 
     Exemplary embodiments of the present invention provide a method for manufacturing a display device, comprising arranging a movement portion of a support member connected to a contact portion of the support member and horizontally and vertically movable, on a side portion of a chuck arranged in an inner space of a chamber such that the contact portion of the support member overlaps an edge portion of a panel member seated on the chuck, attaching an edge portion of an optical member facing the panel member to the contact portion. Exemplary embodiments also provide forming a first pressure, and making the contact portion contact with the edge portion of the panel member through vertically moving the movement portion, forming a second pressure that is higher than the first pressure, and making the panel member and the optical member come in contact with each other due to a difference between the second pressure on the outside of the optical member and the first pressure between the optical member and the panel member, and detaching the contact portion from the edge portion of the panel member and the edge portion of the optical member through horizontally moving the movement portion. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention, and together with the description serve to explain the principles of the invention. 
         FIG. 1  is a cross-sectional view of a bonding apparatus according to exemplary embodiments of the present invention. 
         FIG. 2  is a plan view of a support member according to exemplary embodiments of the present invention. 
         FIGS. 3 through 22  are cross-sectional views and plan views illustrating various examples of a support member according to exemplary embodiments of the present invention. 
         FIGS. 23 through 28  are cross-sectional views explaining processes of manufacturing a display device using a bonding apparatus according to exemplary embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     The invention is described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure is thorough, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity. Like reference numerals in the drawings denote like elements. 
     It will be understood that when an element or layer is referred to as being “on” or “connected to” another element or layer, it can be directly on or directly connected to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on” or “directly connected to” another element or layer, there are no intervening elements or layers present. It may also be understood that for the purposes of this disclosure, “at least one of X, Y, and Z” can be construed as X only, Y only, Z only, or any combination of two or more items X, Y, and Z (e.g., XYZ, XYY, YZ, ZZ). 
     It will be understood that, although the terms first, second, third etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention. 
     Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. 
       FIG. 1  is a cross-sectional view of a bonding apparatus according to an embodiment of the present invention, and  FIG. 2  is a plan view of a support member. 
     Referring to  FIG. 1 , a bonding apparatus may  100  include a chamber  110 , a chuck  120 , and a plurality of support members  130 . The bonding apparatus  100  may bond a panel member M 1  and an optical member M 2  using the plurality of support members  130 . 
     The chamber  110  may be formed to have an inner space. Although not illustrated, on one side of the chamber  110 , a gateway may be formed so that the panel member M 1  and the optical member M 2  may be drawn into or out of the inner space of the chamber  110  through the gateway. A vacuum pump for discharging air may be connected to the other side of the chamber  110  to make the inner space of the chamber  110  in a vacuum state. When the inner space of the chamber  110  is in a vacuum state, a first pressure may be formed in the inner space of the chamber  110 . A vent means for air injection may be connected to a region of a side portion of the chamber  110  except for a region of the side portion where the gateway and the vacuum pump may be installed to make the inner space of the chamber  110  in an atmospheric state. When the inner space of the chamber  110  is in an atmospheric state, a second pressure that is higher than the first pressure may be formed in the inner space of the chamber  110 . 
     The chuck  120  may be arranged on a bottom side of the inner space of the chamber  110  to provide a space where the panel member M 1  may be seated. The chuck  120  may be a vacuum chuck that may be configured to fix the panel member M 1  using vacuum adsorption or an electrostatic chuck that may be configured to fix the panel member M 1  using an electrostatic force. 
     The panel member M 1  may include a substrate for a display, such as an organic light emitting display device or a liquid crystal display device. The substrate for a display may be a bare substrate or a substrate in which switching elements are formed. In the case of the organic light emitting display device, the substrate for a display may be a substrate in which switching elements and a light emitting layer are formed. 
     The panel member M 1  may be a display panel that may include two substrates which may be bonded through the medium of a light emitting layer or a liquid crystal layer. The substrate may be a glass substrate or a flexible substrate that is formed of plastic, for example, polyethyleneterephthalate, polyethylenenaphthalate, polycarbonate, polyarylate, polyetherimide, polyethersulfone, or polyimide. The flexible substrate may be provided as a flexible film. 
     The plurality of support members  130  may be installed in the inner space of the chamber  110 . The plurality of support members  130  may support the optical member M 2  that is drawn into the inner space of the chamber  110 , and may adjust the tension of the optical member M 2  so that the optical member M 2  does not droop downward. 
     The optical member M 2  may be a film having an optical function. For example, in the case where the panel member M 1  of the display device is a substrate for a display in which switching elements are formed, the optical member M 2  may be a protection film that protects the panel member M 1 . The protection film may be temporarily attached to the panel member M 1  in the process of manufacturing a display device, and is separated from the panel member M 1  in the completed display device. In the case where the panel member M 1  is a substrate for a display in which switching elements and a light emitting layer are formed, the optical member M 2  may be an encapsulation film that encapsulates the switching elements and the light emitting layer. In the case where the panel member M 1  is a display panel that includes two substrates which are bonded through the medium of the light emitting layer or the liquid crystal layer, the optical member M 2  may be a polarizing film or an OCA (Optical Clear Adhesive) film. The optical member M 2  may include a base film layer B that is formed of polyimide or polyethyleneterephthalate and an adhesive layer A that is formed of thermosetting resin, such as acrylic resin, on the base film layer B. The base film layer B may further include configurations for implementing the optical function. 
     Each of the plurality of support members  130  may include a movement portion  132  and a contact portion  135 . The support member  130  may further include a connection portion  136 . 
     The movement portion  132  may perform vertical movement to make the contact portion  135 , to which an edge portion of the optical member M 2  may be attached, may come in contact with an edge portion of the panel member M 1 , and an edge portion of the panel member may come in contact with each other, and may move the optical member M 2  close to the side of the panel member M 1  before the optical member M 2  starts to come in close contact with the panel member M 1  due to a difference between the second pressure on the outside of the optical member M 2  and the first pressure that is formed between the optical member M 2  and the panel member M 1  (see  FIGS. 26 and 27 ). As described above, the first pressure may be a pressure in a vacuum state that may be formed through discharging air out of the inner space of the chamber  110  before the contact portion  135  comes in contact with the edge portion of the panel member M 1 . As described above, the second pressure may be a pressure in an atmospheric state that may be formed through injecting air into the inner space of the chamber  110  using the vent means. The second pressure may be higher than the first pressure, and may be formed after the contact portion  135  comes in contact with the edge portion of the panel member M 1 . Accordingly, after the contact portion  135  comes in contact with the edge portion of the panel member M 1 , the pressure between the optical member M 2  and the panel member M 1  may become the first pressure, and the pressure outside the optical member M 2  may become the second pressure. The movement portion  132  may move horizontally to adjust a tension of the optical member M 2  of which the edge portion may be attached to the contact portion  135 , and thus may prevent the optical member M 2  from drooping downward (see  FIG. 25 ). The movement portion  132  may perform horizontal movement so as to detach the contact portion  135  that may be interposed between the edge portion of the panel member M 1  and the edge portion of the optical member M 2  when the panel member M 1  and the optical member M 2  come in close contact with each other (see  FIG. 28 ). 
     The movement portion  132  may be formed in a “           ” shape, but is not limited thereto. The movement portion  132  may be made of a stainless steel material which is durable enough to withstand a small amount of particles, but is not limited thereto.
     The contact portion  135  may be connected to the movement portion  132  to provide a space in which the edge portion of the optical member M 2  that is arranged on the upper portion of the panel member M 1  may be substantially attached. For example, the edge portion of the adhesive layer A of the optical member M 2  may be attached to the contact portion  135 . 
     The contact portion  135  may be formed of a material that does not generate static electricity with the adhesive layer A. This may prevent internal elements of the panel member M 1  from being damaged by static electricity that the touch of the contact portion  135  with the adhesive layer A of the optical member M 2  may generate. For example, when the adhesive layer A of the optical member M 2  is formed of acrylic resin, the contact portion  135  may be formed of a silicon or Teflon™ material. 
     The connection portion may be integrally formed with the contact portion  135 , and may be coupled to the movement portion  132 . The coupling of the connection portion  136  to the movement portion  132  may be performed using, for example, a bolt, but the engagement means is not limited thereto. 
     On the other hand, in the case where the optical member M 2  is in a rectangular shape, the plurality of support members  130  may be divided along sides of the optical member M 2  as illustrated in  FIG. 2 , and may correspond to the sides of the optical member M 2 . The movement portions  132  of the support members  130  may be independently driven, and the contact portions  135  may be formed with a width that becomes narrower in a direction from an outside to an inside of the chuck  120  as illustrated in  FIG. 2  so that the contact portions  135  may not interfere with the movement portions  132  when the movement portion  132  performs horizontal movement. 
     A driver  140  may be connected to the movement portion  132  of the support member  130 , and may include a driving device, such as a motor, to drive the movement portion  132 . 
     A controller  150  may control the driver  140  to enable the movement portion  132  to perform vertical movement and horizontal movement. The controller  150  may control the overall processes for bonding the panel member M 1  and the optical member M 2  to each other. For example, the controller  150  may control a process of fixing the panel member M 1  to the chuck  120 , a process of drawing the optical member M 2  into or out of the inner space of the chamber  110 , and a process of making the inner space of the chamber  110  in a vacuum state or in an atmospheric state. 
     As described above, according to the bonding apparatus  100 , the optical member M 2  and the panel member M 1  may be bonded by making the optical member M 2  and the panel member M 1  come in close contact with each other due to the difference between the second pressure on the outside of the optical member M 2  and the first pressure between the optical member M 2  and the panel member M 1 , rather than the pressing method using a roller or a drum, using the plurality of support members  130  each of which may include the movement portion  132  that may perform the horizontal movement and the vertical movement and the contact portion  135  to which the edge of the optical member M 2  may be attached. 
     According to the bonding apparatus  100  of the exemplary embodiment, the problems of the chopping inferiority, bubbles, wrinkles, detachment phenomenon, and contact inferiority that may occur on the optical member M 2  and the panel member M 1  may be reduced when bonding the optical member M 2  and the panel member M 1 . 
     According to the bonding apparatus  100 , the deterioration of the display quality of the display device that is manufactured by the bonding of the optical member M 2  and the panel member M 1  may be reduced. 
     Various examples of the support member will be described. 
       FIGS. 3 through 22  are cross-sectional views and plan views illustrating various examples of a support member. 
       FIG. 3  illustrates that a support member  230  may include a movement portion  132 , a contact portion  235 , and a connection portion  136 , and the thickness of the contact portion  235  may become thinner as going from the outside to the inside of the chuck  120  shown in  FIG. 1 . The upper surface  235   a  of the contact portion  235  may be an inclined flat surface. As illustrated in  FIG. 4 , by reducing the attachment area between the contact portion  235  and the optical member M 2 , the support member  230  may facilitate the detachment of the contact portion  235  when the optical member M 2  and the panel member M 1  come in close contact with each other to be bonded together due to the difference between the second pressure on the outside of the optical member M 2  and the first pressure between the optical member M 2  and the panel member M 1 . 
       FIG. 5  illustrates that a support member  330  may include a movement portion  132 , a contact portion  335 , and a connection portion  136 , and the thickness of the contact portion  335  may become thinner as going from the outside to the inside of the chuck  120  shown in  FIG. 1 . The upper surface  335   a  of the contact portion  335  may be a curved surface that may be inclined and may be upwardly convex. As illustrated in  FIG. 6 , by reducing the attachment area between the contact portion  335  and the optical member M 2 , the support member  330  may facilitate and smooth the detachment of the contact portion  335  when the optical member M 2  and the panel member M 1  come in close contact with each other to be bonded together. 
       FIG. 7  exemplifies that a support member  430  may include a movement portion  132 , a contact portion  435 , and a connection portion  136 , and the thickness of the contact portion  435  becomes thinner as going from the outside to the inside of the chuck  120  shown in  FIG. 1 . The upper surface  435   a  of the contact portion  435  may be a curved surface that is inclined and may be downwardly concave. As illustrated in  FIG. 8 , by reducing the attachment area between the contact portion  435  and the optical member M 2 , the support member  430  may facilitate and smooth the detachment of the contact portion  435  when the optical member M 2  and the panel member M 1  come in close contact with each other to be bonded together. The support member  430  may enable the optical member M 2  to naturally come in close contact with the panel member M 1  through the contact portion  435  having the concave curved surface. 
       FIG. 9  illustrates that a support member  530  may include a movement portion  132 , a contact portion  535 , and a connection portion  136 , and the contact portion  535  may include grooves  535   a  formed on the upper surface. As illustrated in  FIG. 10 , the grooves  535   a  may be arranged to be spaced apart from each other along predetermined lines. As illustrated in  FIG. 11 , the contact portion  535  may include lattice type grooves  535   b . As illustrated in  FIG. 12 , by reducing the attachment force through heightening a frictional force between the contact portion  535  and the optical member M 2 , the support member  530  may facilitate and smooth detachment of the contact portion  535  when the optical member M 2  and the panel member M 1  come in close contact with each other to be bonded together due to the difference between the second pressure on the outside of the optical member M 2  and the first pressure between the optical member M 2  and the panel member M 1 . 
       FIG. 13  illustrates that a support member  630  may include a movement portion  132 , a contact portion  635 , and a connection portion  136 , and the contact portion  635  may include projections  635   a  formed on the upper surface. The projections  635   a  may be arranged in the same pattern as the pattern of the grooves  535   a  illustrated in  FIG. 10 . As illustrated in  FIG. 14 , by reducing the attachment force through heightening, a frictional force between the contact portion  635  and the optical member M 2  through the projections  635   a , the support member  630  may facilitate and smooth the detachment of the contact portion  635  when the optical member M 2  and the panel member M 1  come in close contact with each other to be bonded together. 
       FIG. 15  illustrates that a support member  730  may include a movement portion  732  and a contact portion  734  that may be integrally formed. The support member  730  may be similar to the support member  130  of  FIG. 1 , and may support the optical member M 2  through the contact portion  734  as shown in  FIG. 16 . Since the support member  730  may include the movement portion  732  and the contact portion  734  that are integrally formed, it may be simply formed without any separate assembling process. The movement portion  732  and the contact portion  734  may be formed of a material that does not generate static electricity with the adhesive layer A of the optical member M 2 , for example, silicon or Teflon™. 
       FIG. 17  illustrates that a support member  830  may include a movement portion  832  and a contact portion  834  that may be integrally formed, and a coating layer  835  formed on the contact portion  834 . The movement portion  832  and the contact portion  834  may be formed of a stainless steel material having durability, and the coating layer  835  may be formed of a material that does not generate static electricity, for example, silicon or Teflon™. The support member  830  may be similar to the support member  130  of  FIG. 1 , and may enable the optical member M 2  to be attached to the coating layer  835  with durability without being affected by the static electricity through the movement portion  832  and the contact portion  834  as illustrated in  FIG. 18 . 
       FIG. 19  illustrates that a support member  930  may include a movement portion  932 , a contact portion  934 , and a rotatable holding portion  935 . The support member  930  may be similar to the support member  130  of  FIG. 1 , and may make it possible to adjust a tension of the optical member M 2  in a state where the optical member M 2  is firmly fixed by attaching the optical member M 2  on the contact portion  934  and fixing the optical member M 2  through the holding portion  935  as illustrated in  FIG. 20 . 
       FIG. 21  illustrates that a support member  1030  may include a movement portion  1032 , a contact portion  1034 , and a holding portion  1035  having magnetism. The support member  1030  may be similar to the support member  130  of  FIG. 1 , and may make it possible to fix the optical member M 2  through the holding portion  1035  having magnetism after the optical member M 2  is attached to the contact portion  1034  as illustrated in  FIG. 22 . For example, the movement portion  1032  may be formed of a material that may form magnetic force with the holding portion  1035 . 
     A method for manufacturing a display device using a bonding apparatus  100  according to exemplary embodiments of the present invention will be described. 
       FIGS. 23 through 28  are cross-sectional views explaining processes of a method for manufacturing a display device using a bonding apparatus. 
     Referring to  FIG. 23 , a movement portion  132 , which may be connected to a contact portion  135  so that the contact portion  135  overlaps an edge portion of a panel member M 1  that is seated on a chuck  120  arranged inside a chamber  110 , and may move horizontally and vertically, may be arranged on a side portion of the chuck  120 . The contact portion  135  may be arranged on the edge portion of the panel member M 1  to be spaced apart. On the other hand, in the case where the contact portion  135  does not overlap the panel member M 1  even though the movement portion  132  is arranged on the side portion of the chuck  120 , the movement portion  132  may perform horizontal movement or vertical movement to make the contact portion  135  overlap the edge portion of the panel member M 1 . 
     The panel member M 1  may include a substrate for a display of a display device, such as an organic light emitting display device or a liquid crystal display device. The substrate for a display may be a bare substrate or a substrate in which switching elements are formed. In the case of the organic light emitting display device, the substrate for a display may be a substrate in which switching elements and a light emitting layer are formed. 
     The panel member M 1  may be a display panel that may include two substrates which are bonded through the medium of a light emitting layer or a liquid crystal layer. The substrate may be a glass substrate or a flexible substrate that is formed of plastic, for example, polyethyleneterephthalate, polyethylenenaphthalate, polycarbonate, polyarylate, polyetherimide, polyethersulfone, or polyimide. The flexible substrate may be provided as a flexible film. 
     Referring to  FIG. 24 , the edge portion of the optical member M 2  that is drawn into the inner space of the chamber  110  may be attached to the contact portion  135 . The optical member M 2  may include a base film layer B and an adhesive layer A that may be formed on the base film layer B. The adhesive layer A of the optical member M 2  may be covered by a release paper before the optical member M 2  is drawn into the inner space of the chamber  110 . 
     The optical member M 2  may be a film having an optical function. For example, if the panel member M 1  of the display device is a substrate for a display in which switching elements are formed, the optical member M 2  may be a protection film that protects the panel member M 1 . The protection film may be temporarily attached to the panel member M 1  in the process of manufacturing a display device, and may be separated from the panel member M 1  in the completed display device. In the case where the panel member M 1  is a substrate for a display in which switching elements and a light emitting layer are formed, the optical member M 2  may be an encapsulation film that encapsulates the switching elements and the light emitting layer. In the case where the panel member M 1  is a display panel that includes two substrates which are bonded through the medium of the light emitting layer or the liquid crystal layer, the optical member M 2  may be a polarizing film or an OCA (Optical Clear Adhesive) film. The optical member M 2  may include a base film layer B that may be formed of polyimide or polyethyleneterephthalate and an adhesive layer A that may be formed of thermosetting resin, such as acrylic resin, on the base film layer B. The base film layer B may further include configurations for implementing the optical function. 
     Although not illustrated, the optical member M 2  may be drawn into the inner space of the chamber  110  in a state where it may be fixed to a separate chuck, and after the optical member M 2  is attached to the contact portion  135 , the separate chuck may be separated from the optical member M 2  to be discharged out of the chamber  110 . 
     Referring to  FIG. 25 , the tension of the optical member M 2  may be adjusted by horizontally moving the movement portion  132 . Accordingly, the optical member M 2  may be maintained to be flat. 
     Referring to  FIG. 26 , a first pressure may be formed by making the inner space of the chamber  110  in a vacuum state, and the contact portion  135  may be made to come in contact with the edge portion of the panel member M 1  by vertically moving the movement portion  132 . The vacuum state may be formed by discharging air out of the inner space of the chamber  110  using a vacuum pump (not illustrated) under the control of the controller  150 . The vertical movement of the movement portion  132  may be performed by the driver  140  that is controlled by the controller  150 . 
     Referring to  FIG. 27 , a second pressure that may be higher than the first pressure may be formed in the chamber  110  by making the outside of the optical member M 2  in an atmospheric state through ventilation of the chamber  110 , and thus the panel member M 1  may come in close contact with the optical member M 2  due to the difference between the second pressure on the outside of the optical member M 2  and the first pressure between the optical member M 2  and the panel member M 1 . The ventilation of the chamber  110  may be performed by injecting air into the inner space of the chamber  110  using a vent means (not illustrated) under the control of the controller  150 . 
     Referring to  FIG. 28 , the contact portion  135  may be detached from the edge portion of the panel member M 1  and the edge portion of the optical member M 2  by horizontally moving the movement portion  132 . Accordingly, the edge portion of the panel member M 1  and the edge portion of the optical member M 2  may come in close contact with each other to complete the bonding of the panel member M 1  to the optical member M 2 . The horizontal movement of the movement portion  132  may be performed by the driver  140  that is controlled by the controller  150 . 
     The bonding of the panel member M 1  to the optical member M 2  as described above may be bonding of a protection film to the substrate for a display. The bonding of the panel member M 1  to the optical member M 2  may be bonding of an encapsulation film to the substrate for a display on which switching elements and a light emitting layer may be formed. The bonding of the panel member M 1  to the optical member M 2  may be bonding of a polarizing film to a display panel that may include two substrates bonded together by the medium of the light emitting layer or the liquid crystal layer. The bonding of the panel member M 1  to the optical member M 2  may be bonding of an OCA (Optical Clear Adhesive) film to the display panel. In this case, a window may be attached onto the OCA film. Through the bonding of the panel member M 1  and the optical member M 2 , a display device may be manufactured. 
     It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.