Patent Publication Number: US-2007120468-A1

Title: Display apparatus and method of manufacturing the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application claims priority from and the benefit of Korean Patent Application No. 2005-0115884, filed on Nov. 30, 2005, which is hereby incorporated by reference for all purposes as if fully set forth herein.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a display apparatus and a method of manufacturing the same, and more particularly, to a display apparatus that may prevent an insulating substrate from sagging in a manufacturing process, and a method of manufacturing the same.  
      2. Discussion of the Background  
      There are various display apparatuses such as liquid crystal displays (LCD), plasma display panels (PDP), etc. Among various display apparatuses, an organic light emitting diode (OLED) has recently attracted attention because it is driven with a low voltage, is thin and light, has a wide viewing angle, has a relatively short response time, etc.  
      Such an OLED may be a passive matrix or an active matrix device according to its driving method. Further, the OLED may be a low molecular weight OLED or a polymer OLED according to the molecular weight of an organic layer, such as a hole injecting layer (HIL) and an emission layer (EML).  
      Meanwhile, a thermal evaporation method may be employed to form an organic layer of the low molecular weight OLED. Before forming the organic layer, a manufacturing process may be performed in which the parts of the display apparatus where the organic layer is to be deposited face upward. On the other hand, while the organic layer is being formed by the thermal evaporation method, the display apparatus is placed above a deposition source, and the parts where the organic layer is to be deposited face down toward the deposition source. For this, the display apparatus is turned upside down.  
      Nowadays, large display apparatuses are much in demand. However, when a large display apparatus is turned upside down, the center of the insulating substrate may sag. Therefore, the organic layer is not uniformly deposited throughout the insulating substrate, so that the display apparatus may be defective. Further, when a plastic substrate is utilized as the insulating substrate, the sagging problem may be worse. Likewise, this problem may arise when a common electrode is formed on the organic layer by thermal evaporation.  
      To solve the sagging problem, a display apparatus may be disposed and fastened between a substrate supporter, made of a magnetic substance, and a magnet attracting the substrate supporter and is then turned upside down to thereby form the organic layer or/and the common electrode. However, sagging of the insulating substrate may still occur when using the magnet and the substrate supporter.  
     SUMMARY OF THE INVENTION  
      The present invention provides a display apparatus that may effectively prevent an insulating substrate from sagging in a manufacturing process.  
      The present invention also provides a display apparatus manufacturing method that may effectively prevent an insulating substrate from sagging in the manufacturing process.  
      Additional aspects and/or advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present invention.  
      The present invention discloses a display apparatus including an insulating substrate, a metal film formed on a first surface of the insulating substrate, a thin film transistor formed on a second surface of the insulating substrate, a first passivation film formed on the thin film transistor, a pixel electrode formed on the passivation film electrically connected with the thin film transistor and forming a pixel region, an organic layer formed on the pixel electrode, and a common electrode formed on the organic layer.  
      The present invention also discloses a method for manufacturing including preparing a display apparatus having an insulating substrate, a metal film formed on a first surface of the insulating substrate, and a thin film transistor formed on a second surface of the insulating substrate, seating the display apparatus in a seating unit having an accommodating part to accommodate the display apparatus therein and a magnet provided in the accommodating part while the metal film faces the magnet, placing a substrate supporter having a magnetic substance on the display apparatus, rotating the display apparatus upside down in the state that the display apparatus and the substrate supporter are both attracted by a magnetic force to the magnet, and depositing a deposition material on the display apparatus.  
      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 and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and together with the description serve to explain the principles of the invention.  
       FIG. 1  is an equivalent circuit diagram illustrating a pixel of a display apparatus according to a first exemplary embodiment of the present invention.  
       FIG. 2  is a sectional view of the display apparatus according to the first exemplary embodiment of the present invention.  
       FIG. 3A ,  FIG. 3B ,  FIG. 3C ,  FIG. 3D , and  FIG. 3E  are sectional views sequentially showing a method of fabricating the display apparatus according to the first exemplary embodiment of the present invention.  
       FIG. 4  and  FIG. 5  are a sectional view and a rear view of a display apparatus, respectively, according to a second exemplary embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF 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 embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, 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.  
      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.  
       FIG. 1  is an equivalent circuit diagram of a display apparatus according to a first exemplary embodiment of the present invention.  
      Referring to  FIG. 1 , one pixel includes a plurality of signal lines. The signal lines include a gate line to transmit a scan signal, a data line to transmit a data signal, and a driving voltage line to apply a driving voltage. The data line and the driving voltage line are arranged adjacent to and in parallel with each other. Further, the gate line crosses both the data line and the driving voltage line.  
      Each pixel includes an organic light emitting device LD, a switching transistor Tsw, a driving transistor Tdr, and a capacitor C.  
      The driving transistor Tdr has a control terminal connected to the switching transistor Tsw, an input terminal connected to the driving voltage line, and an output terminal connected to the organic light emitting device LD.  
      The organic light emitting device LD has an anode connected to the output terminal of the driving transistor Tdr, and a cathode connected to a common voltage Vcom. The organic light emitting device LD emits light with brightness varying according to the intensity of a current from the driving transistor Tdr, thereby displaying an image. Here, the intensity of the current from the driving transistor Tdr varies according to voltage applied between the control terminal and the output terminal of the driving transistor Tdr.  
      The switching transistor Tsw has a control terminal connected to the gate line, an input terminal connected to the data line, and an output terminal connected to the control terminal of the driving transistor Tdr. The switching transistor Tsw transmits the data signal from the data line to the driving transistor Tdr in response to the scan signal applied to the gate line.  
      The capacitor C is connected between the control terminal and the input terminal of the driving transistor Tdr. The capacitor C stores and maintains the data signal to be inputted to the control terminal of the driving transistor Tdr.  
      Below, the display apparatus according to the first exemplary embodiment will be described in more detail with reference to  FIG. 2 . In  FIG. 2 , a thin film transistor  20  is the driving transistor and the display apparatus is top-emission type.  
      The display apparatus  1  according to the first exemplary embodiment includes an insulating substrate  10 , a metal film  15  formed on a first surface  10   a  of insulating substrate  10 , and a metal passivation film  18  for protecting the metal film  15 . Further, the display apparatus  1  comprises the thin film transistor  20 , a passivation film  31 , a pixel electrode  32 , a partition wall  40 , an organic layer  50 , and a common electrode  61 , which are formed on a second surface  10   b  of the insulating substrate  10 .  
      The insulating substrate  10  includes a dielectric material such as glass, quartz, ceramic, plastic or the like. Typically, a glass substrate or a plastic substrate is used as the insulating substrate  10 .  
      A magnetic film such as the metal film  15 , is arranged on the first surface  10   a  of the insulating substrate  10 . The metal film  15  may be formed on the entire insulating substrate  10 . The metal film  15  may have a thickness of 50 μm through 1000 μm depending on a raw material of the metal film  15  and the magnetic force of a magnet  280  provided in a manufacturing apparatus  100  (to be described later) for the display apparatus but is not limited thereto. The metal film  15  includes one of iron, nickel, and cobalt, or an alloy thereof and may be formed by a sputtering method. Here, iron, nickel, and cobalt are ferromagnetic substances which have good attraction to the magnet  280  of the manufacturing apparatus  100 .  
      The metal film  15 , which is formed on the first surface  10   a  of the insulating substrate  10 , is closely attached to the magnet  280  by the attractive force of the magnet  280  when the display apparatus  1  is turned upside down during manufacturing so as to form the organic layer  50  or/and the common electrode  61  by a thermal evaporation method. Thus, the metal film  15  may prevent the insulating substrate  10  from sagging while forming the organic layer  50  or/and the common electrode  61 .  
      The metal passivation film  18  is arranged on the metal film  15  to protect the metal film  15 . Like the passivation film  31 , the metal passivation film  18  comprises silicon nitride (SiNx) or/and an organic material. In this embodiment, silicon nitride (SiNx) is formed as the metal passivation film  18  by chemical vapor deposition (CVD). When organic material is used as the metal passivation film  18 , a slit coating method or a spin coating method can be used to form the metal passivation film  18 .  
      The metal passivation film  18  is formed to prevent the metal film  15  from being damaged (e.g., corroded). The metal passivation film  18  may be formed directly after forming the metal film  15 . Alternatively, the metal passivation film  18  may be formed after the organic layer  50  or/and the common electrode  61  are completed by the thermal evaporation method.  
      The thin film transistor  20  includes a gate electrode  21 , a gate insulating film  22 , a semiconductor layer  23 , an ohmic contact layer  24 , a source electrode  25  and a drain electrode  26 .  
      The gate insulating film  22  may include silicon nitride (SiNx) or the like and is formed on the gate electrode  21 . The gate electrode  21  branches from a gate line (not shown) and may be a single layer or a multi layer.  
      The semiconductor layer  23 , including amorphous silicon, and the ohmic contact layer  24 , including hydrogenated n+ amorphous silicon highly doped with an n-type dopant, may be formed in sequence on the gate insulating film  22  corresponding to the gate electrode  21 . Here, the ohmic contact layer  24  is separated into two parts with respect to the gate electrode  21 .  
      The source electrode  25  and the drain electrode  26  are formed on the ohmic contact layer  24  and the gate insulating layer  22 . Further, the source electrode  25  and the drain electrode  26  are separated into with respect to the gate electrode  21 .  
      In the drawing, the thin film transistor  20  includes amorphous silicon but may alternatively include polysilicon.  
      The passivation film  31  is formed on the source electrode  25 , the drain electrode  26 , and the exposed portion of the semiconductor layer  23  between the source electrode  25  and drain electrode  26 . The passivation film  31  may include silicon nitride (SiNx) or/and the organic material. The passivation film  31  includes a contact hole  27  to expose the drain electrode  26 .  
      The pixel electrode  32  is formed on the passivation film  31 . The pixel electrode  32  may be an anode, and in this case, it supplies holes to the emission layer  52 . The pixel electrode  32  may include a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO), etc., and may be formed by sputtering. Here, the pixel electrode  32  may be patterned to have an approximately rectangular shape from a plan view.  
      A partition wall  40  is formed between the pixel electrodes  32 . The partition wall  40  is shaped like a mesh and divides the pixel electrodes  32 , thereby defining a pixel region. Further, the partition wall  40  is formed on the thin film transistor  20  and the contact hole  27 . Here, the partition wall  40  prevents the source electrode  25  and the drain electrode  26  of the thin film transistor  20  from short-circuiting with the common electrode  61 . The partition wall  40  may include a photosensitive material such as an acrylic resin, a polyimide resin, etc., which has heat resistance and solvent resistance and an inorganic material such as SiO 2  and TiO 2 . Further, the partition wall  40  may be a double-layered structure including an organic layer and an inorganic layer. The partition wall  40  can be formed by photolithography or an inkjet method.  
      The organic layer  50  is formed on the pixel electrode  32  uncovered by the partition wall  40 . The organic layer  50  includes the hole injecting layer  51  and the emission layer  52 .  
      The hole injecting layer  51  includes a hole injecting material, which is a low molecular weight organic material and may be formed by the thermal evaporation method.  
      The emission layer  52  includes sub-layers such as a red emission layer  52   a , a green emission layer  52   b  and a blue emission layer  52   c , which are alternately formed. The emission layer  52  includes an emission material, which is a low molecular weight organic material and may be formed by the thermal evaporation method.  
      A hole from the pixel electrode  32  and an electron from the common electrode  61  combine into an exciton in the emission layer  52 , and light is emitted while the exciton is deactivated.  
      The hole injecting layer  51  and the emission layer  52  of the display apparatus  1  according to the first exemplary embodiment of the present invention are formed by the thermal evaporation method in the state that the metal film  15  prevents the insulating substrate  10  from sagging, thereby making the substrate  10  flat. Therefore, the hole injecting layer  51  and the emission layer  52  may have uniform thickness regardless of positions of the insulating substrate  10 . Thus, it may be possible to prevent a short-circuit between the pixel electrode  32  and the common electrode  61  in the pixel region, which occurs when the organic layer  50  is not uniformly formed due to the sagging insulating substrate  10 .  
      The common electrode  61  is provided on the partition wall  40  and the emission layer  52 . The common electrode  61  may be a cathode, and in this case, it supplies electrons to the emission layer  52 .  
      The common electrode  61  may include a transparent conductive material such as ITO or IZO, an alloy of magnesium and silver, or an alloy of calcium and silver. The common electrode  61  may be a double-layered structure including a lower layer of a metal alloy and an upper layer of ITO or IZO. The common electrode  61  may be formed by the sputtering method. Alternatively, the common electrode  61  can be formed by the thermal evaporation method like the organic layer  50 . The thickness of the common electrode  61  may vary according to the materials but should be uniform throughout the insulating substrate  10 . In the case where the thickness of the common electrode  61  is not uniform, thin parts may cause an excessively large resistance, and thus a common voltage is not efficiently applied while thick parts may cause the common electrode  61  to be opaque, and thus brightness noticeably decreases while light passes through the common electrode  61 .  
      The common electrode  61  of the display apparatus  1  according to the first exemplary embodiment of the present invention is formed in the state that the insulating substrate  10  is prevented from sagging by the metal film  15  and is flat, so that the common electrode  61  may be formed with a uniform thickness regardless of the positions of the insulating substrate  10 .  
      Further, the display apparatus  1  may include an electron transfer layer (not shown) and an electron injecting layer (not shown) between the emission layer  52  and the common electrode  61 . Also, the display apparatus  1  may include an additional passivation film for protecting the common electrode  61 , and an encapsulating member (not shown) to prevent water and air permeating into the organic layer  50 . Here, the encapsulating member may include an encapsulating resin and/or an encapsulating can.  
      In the display apparatus  1  with this configuration according to the first exemplary embodiment, when the insulating substrate  10  is turned upside down to form the organic layer  50  or/and the common electrode  61 , the magnetic force of the magnet  280  attracts the metal film  15 . As the metal film  15  is attached to the magnet  280 , the insulating substrate  10  may be prevented from sagging while the organic layer  50  or/and the common electrode  61  are formed, thereby preventing the insulating substrate  10  from being damaged. Further, the pixel electrode  32  and the common electrode  61  may be prevented from being short-circuited in the pixel region where the organic layer  50  is not uniformly formed by the sagged insulating substrate  10 , and thus the common electrode  61  is uniformly formed, thereby enhancing the performance of the display apparatus  1 .  
      Below, a method of manufacturing the display apparatus according to the first exemplary embodiment of the present invention will be described with reference to  FIG. 3A ,  FIG. 3B ,  FIG. 3C ,  FIGS. 3D , and  3 E.  
      Before describing the method of fabricating the display apparatus according to the first exemplary embodiment, the manufacturing apparatus  100  used herein will be described with reference to  FIG. 3D  and  FIG. 3E .  
      The manufacturing apparatus  100  for the display apparatus includes a seating unit  200  and a rotating unit  300 .  
      The seating unit  200  includes a base  210 , an accommodating part  211  formed on the base  210 , a supporting wall  212  upwardly extended from the edge of the accommodating part  211 , a holder  230  penetrating the supporting wall  212 , a mover  250  moving the holder  230 , the magnet  280 , which may be stationary in the accommodating part  211 , and a shadow mask  290  including a material to be attracted by the magnet  280  and used as a detachable substrate supporter.  
      The accommodating part  211  flatly formed on the base  210  accommodates a display substrate  5  during manufacturing.  
      The supporting wall  212  includes a plurality of through holes  234  in the center thereof. The supporting wall  212  supports the holder  230  moving between a locking position and a releasing position through the through hole  234 .  
      The holder  230  holds the display substrate  5  and the shadow mask  290  after the display substrate  5  and the shadow mask  290  are sequentially accommodated in the accommodating part  211 . The holder  230  is connected to the mover  250 , and moves between the locking position and the releasing position as the mover  250  moves forward and backward. Here, the mover  250  may be a known means such as a motor.  
      The magnet  280 , which corresponds to the shape of the accommodating part  211 , is closely attached to the base  210 . Therefore, the display substrate  5  may be closely attached to the magnet  280  when accommodated in the accommodating part  211  during manufacturing. The magnetic force of the magnet  280  may range from 20,000 gauss to 70,000 gauss to provide an adequate attractive force with the metal film  15  and the shadow mask  290 . Here, the magnet may be a permanent magnet or an electromagnet. In this embodiment, the magnet is implemented by the electromagnet, and the manufacturing apparatus  100  further includes a current supply (not shown) to supply a current to the electromagnet for generating the magnetic force.  
      The shadow mask  290  is provided on the display substrate  5 , which contacts the magnet  280 . The shadow mask  290  is used as the substrate supporter and includes chrome alloy steel, nickel alloy steel, etc., which are attracted by the magnetic force of the magnet  280 . The shadow mask  290  includes a deposition hole (not shown), so that a deposition material evaporated from a source  500  may pass through the deposition hole and be deposited on the display substrate  5 . Further, the shadow mask  290  supports the display substrate  5  by the attraction with the magnet  280  when the seating unit  200  is turned upside down, so that the center of the rotated insulating substrate  10  may be prevented from sagging. Thus, the shadow mask  290  and the holder  230  support the display substrate  5 , thereby preventing the insulating substrate  10  of the display substrate  5  from sagging.  
      Further, the rotating unit  300  is provided at one end of the seating unit  200 .  
      The rotating unit  300  includes a rotating shaft  310  connected to an external power source (not shown) and rotated by the power source, and a rotating body  320  surrounding the rotating shaft  310  and rotating the seating unit  200  upside down by the rotational force of the rotating shaft  310 .  
      The rotating unit  300  operates to rotate the seating unit  200  upside down, wherein the display substrate  5  is seated in the seating unit  200 . Thus, the display substrate  5  may be rotated so that the parts thereof needing the deposition face down. Alternatively, the rotating unit  300  may be connected to opposite ends of a short or long side of the seating unit  200  as long as the seating unit  200  is rotated upside down.  
      Below, the method of manufacturing the display apparatus according to the first exemplary embodiment of the present invention will be described.  
      As shown in  FIG. 3A  and  FIG. 3B , the metal film  15  is formed on a first surface of the insulating substrate  10 , and the pixel electrode  32  is formed on the second surface of the insulating substrate  10 .  
      In more detail, the metal film  15  is formed to have a thickness of 50 μm through 1000 μm on the entire first surface of the insulating substrate  10 . The metal film  15  includes one of ferromagnetic substances such as iron, nickel, and cobalt, or alloy thereof, and may be formed by the sputtering method.  
      Then, as shown in  FIG. 3B , the thin film transistor  20 , the passivation film  31 , and the pixel electrode  32  are formed on the second surface of the insulating substrate  10 , thereby preparing the display substrate  5 .  
      The thin film transistor  20  includes a channel made of amorphous silicon and can be manufactured by a known method.  
      After forming the thin film transistor  20 , the passivation film  31  is formed on the thin film transistor  20 . The passivation film  31  can be formed by CVD when it includes silicon nitride. Then, the passivation film  31  is photolithographed to provide the contact hole  27  exposing the drain electrode  26 . After forming the contact hole  27 , the pixel electrode  32  is formed to be connected to the drain electrode  26  through the contact hole  27 . Here, the pixel electrode  32  can be formed by depositing ITO by a sputtering method and patterning it.  
      Then, as shown in  FIG. 3C , the display substrate  5  is seated in the accommodating part  211  of the manufacturing apparatus  100 , so that the metal film  15  of the display substrate  5  faces the magnet  280  of the accommodating part  211 . At this time, the holder  230  is in the releasing position.  
      As shown in  FIG. 3D , the shadow mask  290  is seated on the display substrate  5 . Then, the holder  230  is moved to the locking position by the mover  250 , thereby holding the display substrate  5  and the shadow mask  290 . In this process, the magnet  280  receives electric current from the current supply (not shown) and generates magnetic force. Thus, the magnetic force of the magnet  280  causes the attraction between the magnet  280  and the metal film  15  and between the magnet  280  and the shadow mask  290 .  
      As shown in  FIG. 3E , the display substrate  5  is turned upside down, and then the deposition material is deposited on the display substrate  5 .  
      To turn the display substrate  5  upside down, the rotating shaft  310  of the rotating unit  300  connected to one end of the seating unit  200  is rotated by the external power source (not shown). Thus, the rotational force of the rotating shaft  310  is transferred to the rotating body  320  surrounding the rotating shaft  310 , so that the rotating unit  300  rotates the seating unit  200  upside down to be disposed above and face to a deposition source unit  400 .  
      Then, to deposit the deposition material on the display substrate  5  by the thermal evaporation method, the deposition material is evaporated from a plurality of sources  500  provided on the deposition source unit  400  and then deposited on the display substrate  5  through the deposition hole. By changing the deposition source  500  or/and the shadow mask  290 , the hole injecting layer  51  and the emission layer  52  can be deposited on the pixel electrode  32 . Likewise, the common electrode  61  can be deposited as necessary on the organic layer  50 .  
      In the rotating and deposition processes for the display substrate  5 , the rotated insulating substrate  10  may sag due to gravity. However, the attraction between the magnet  280  and the shadow mask  290  may decrease the sag of the insulating substrate  10 , and the attraction between the magnet  280  and the metal film  15  may also decrease the sag of the insulating substrate  10 .  
      After the deposition process, the display substrate  5  is removed from the manufacturing apparatus  100 , and the metal passivation film  18  may be formed on the metal film  15  by CVD at a low temperature, thereby completing the display apparatus  1  according to the first exemplary embodiment.  
      Alternatively, after forming the metal film  15 , the metal passivation film  18  can be formed just before forming the thin film transistor  20 . In this case, the display substrate  5  can be manufactured by CVD at a high temperature before forming the organic layer  50  which is susceptive to heat, thereby enhancing a manufacturing efficiency thereof.  
      In the method of manufacturing the display apparatus according to the first exemplary embodiment of the present invention, the insulating substrate  10  of the display substrate  5  may be prevented from sagging. Further, the insulating substrate  10  is maintained substantially flat, so that the insulating substrate  10  may be prevented from being damaged. Further, it is possible to avoid producing a defective display apparatus where the pixel electrode  32  and the common electrode  61  short-circuit in the pixel region due to the organic layer  50  not being uniformly formed on a sagged insulating substrate. Also, the common electrode  61  is uniformly formed, thereby enhancing the performance of the display apparatus  1 .  
      Below, a display apparatus according to a second exemplary embodiment of the present invention will be described with reference to  FIG. 4  and  FIG. 5  while emphasizing difference from that of the first exemplary embodiment.  FIG. 4  and  FIG. 5  are a sectional view and a rear view, respectively, of a display apparatuses according to a second exemplary embodiment of the present invention.  
      A display apparatus  2  according to the second exemplary embodiment of the present invention is a bottom-emission type. A metal film  16  is formed with an opening  17  at a position corresponding to the pixel region, thereby allowing emission of light to that passes through the insulating substrate  10 . The pixel electrode  32  includes a transparent metal or a transparent conductive material, and the common electrode  61  may include an opaque metal or an opaque conductive material.  
      Further, a method of manufacturing the display apparatus according to the second exemplary embodiment is similar to that of the first exemplary embodiment except that a mask or the like is used in forming the opening  17  when the metal film  16  is formed by the sputtering method.  
      Thus, the display apparatus  2  and its manufacturing method according to the second exemplary embodiment of the present invention can obtain the same effect as that of the first exemplary embodiment.  
      In the foregoing embodiment, an OLED is exemplarily described as the display apparatuses  1  and  2 . However, the present invention can be applied to various display apparatuses, such as an LCD, as long as a certain material is deposited thereto by the thermal evaporation method.  
      As described above, the present invention provides a display apparatus with a structure that may be used to effectively prevent an insulating substrate from sagging in a manufacturing process and a method of manufacturing the same.  
      It will be apparent to those skilled in the art that various modifications and variation 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.