Patent Publication Number: US-2015060838-A1

Title: Organic light emitting diode display device having built-in touch panel and method of manufacturing the same

Description:
This present patent document is a divisional of U.S. patent application Ser. No. 13/943,149, filed Jul. 16, 2013 which claims the benefit of priority of Korean Patent Application No. 10-2012-0147137, filed on Dec. 17, 2012, which is hereby incorporated by reference as if fully set forth herein. 
    
    
     FIELD OF THE DISCLOSURE 
     The present disclosure relates to an organic light emitting diode (OLED) display device having a built-in touch panel, and more particularly, to an OLED display device having a built-in touch panel in which an OLED array and a touch array are formed on respective flexible substrates and thus the OLED display device has a decreased thickness and improved flexibility and a manufacturing method thereof. 
     DISCUSSION OF THE RELATED ART 
     Image display devices, which display a variety of information on a screen, are a core technology of information and communication and are developed towards a trend of thinner, lighter, portable, and high performance. Thus, organic light emitting diode (OLED) display devices, which display an image by controlling emission amount of an organic emission layer (EML), have received attention as a flat panel display device that may address problems in terms of weight and volume which occur in cathode ray tubes (CRTs). 
     An OLED display device includes an OLED, which is self-emissive and emits light using a thin EML between electrodes, and thus may be realized as a thin film such as paper. 
     An OLED array includes a thin film transistor (TFT) formed in each subpixel region of a substrate and the OLED connected to the TFT and including a first electrode (i.e., anode), an EML, and a second electrode (i.e., cathode) which are sequentially formed. When a voltage is applied between the first and second electrodes, holes and electrons are recombined in the EML to form excitons and, when the excitons drop to a ground state, light is emitted. 
     In particular, the OLED array is formed on a flexible substrate and thus an OLED display device having flexibility may be manufactured. More particularly, an exfoliation layer is formed on a rigid substrate formed of, for example, glass, the flexible substrate is formed on the exfoliation layer, and the OLED array is formed on the flexible substrate. Subsequently, the exfoliation layer is separated from the flexible substrate. 
     Meanwhile, to manufacture a flexible OLED display device, an encapsulation substrate covering an OLED array is also formed of a plastic film. However, it is impossible to perform a manufacturing process such as chemical vapor deposition (CVD), sputtering, or the like on the film. Thus, only an add-on type in which a touch array is attached to a film may be applied to the flexible OLED display device. 
     SUMMARY 
     An OLED display device includes an OLED array formed on a lower flexible substrate, a touch array formed on an upper flexible substrate, and an adhesive layer adhering the upper flexible substrate to the lower flexible substrate such that the touch array and the OLED array face each other. 
     The touch array may include X and Y electrodes crossing each other, a pad part, and a routing line connecting the pad part to the X and Y electrodes, wherein the pad part is connected to the OLED array via an anisotropic conductive paste. 
     In another aspect of the present invention, a method of manufacturing an OLED display device having a built-in touch panel includes forming a lower flexible substrate on a lower rigid substrate with a lower exfoliation layer positioned therebetween and forming an OLED array on the lower flexible substrate, forming an upper flexible substrate on an upper rigid substrate with an upper exfoliation layer positioned therebetween and forming a touch array on the upper flexible substrate, adhering the upper rigid substrate to the lower rigid substrate using an adhesive layer such that the touch array and the OLED array face each other, separating the upper exfoliation layer from the upper flexible substrate, cutting the lower rigid substrate on a unit panel basis, and separating the lower exfoliation layer from the lower flexible layer. 
     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 
       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: 
         FIG. 1  is a sectional view of an organic light emitting diode (OLED) display device having a built-in touch panel, according to an embodiment of the present invention; 
         FIG. 2A  is a sectional view of an OLED array of the OLED display device of  FIG. 1 ; 
         FIG. 2B  is a sectional view of a touch array of the OLED display device of  FIG. 1 ; 
         FIGS. 3A through 3H  are sectional views sequentially illustrating a method of manufacturing the OLED display device having a built-in touch panel, according to a first embodiment of the present invention; 
         FIG. 4A  is a photograph of an upper flexible substrate from which an upper exfoliation layer is separated using ultraviolet irradiation; 
         FIGS. 4B and 4C  are photographs showing a case in which wiring defects of the touch array do not occur when the upper exfoliation layer is separated upon ultraviolet irradiation; 
         FIGS. 5A through 5F  are sectional views sequentially illustrating a method of manufacturing the OLED display device having a built-in touch panel, according to a second embodiment of the present invention; 
         FIG. 6A  is a photograph of an upper flexible substrate from which an upper exfoliation layer is separated by application of a certain voltage; and 
         FIGS. 6B and 6C  are photographs showing a case in which wiring defects of a touch array do not occur when the upper exfoliation layer is separated by application of a voltage. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
     Hereinafter, embodiments of an organic light emitting diode display device having a built-in touch panel will be described in detail with reference to the accompanying drawings. 
       FIG. 1  is a sectional view of an organic light emitting diode (OLED) display device having a built-in touch panel, according to an embodiment of the present invention.  FIG. 2A  is a sectional view of an OLED array  140  of the OLED display device of  FIG. 1 .  FIG. 2B  is a sectional view of a touch array  160  of the OLED display device of  FIG. 1 . 
     As illustrated in  FIG. 1 , the OLED display device having a built-in touch panel includes the OLED array  140  formed on a lower flexible substrate  120   a  and the touch array  160  formed on an upper flexible substrate  120   b.  The lower and upper flexible substrates  120   a  and  120   b  are adhered to each other by an adhesive layer  170  such that the touch array  160  and the OLED array  140  face each other. 
     In particular, the lower flexible substrate  120   a  is a plastic film formed of at least one organic material selected from among polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyethylene ether phthalate, polycarbonate, polyarylate, polyether imide, polyether sulfonate, polyimide, and polyacrylate. 
     A buffer layer  130  is formed between the lower flexible substrate  120   a  and the OLED array  140 . The buffer layer  130  improves adhesion between the OLED array  140  and the lower flexible substrate  120   a  and prevents moisture or impurities from diffusing into the OLED array  140  from the lower flexible substrate  120   a.  The buffer layer  130  may be a single layer structure of an inorganic insulator such as silicon oxide (SiO x ), silicon nitride (SiN x ), or the like or a double-layered structure of SiO x  and SiN x . 
     The OLED array  140  is formed on the lower flexible substrate  120   a  with the buffer layer  130  positioned therebetween. As illustrated in  FIG. 2A , the OLED array  140  includes a thin film transistor (TFT) including a gate electrode  140   a,  a gate insulating layer  141 , a semiconductor layer  142 , a source electrode  143   a,  and a drain electrode  143   b  and an OLED including a first electrode  145 , an organic emission layer (EML)  147 , and a second electrode  148 . 
     In particular, the gate electrode  140   a  is formed on the buffer layer  130 , and the gate insulating layer  141  is formed to cover the gate electrode  140   a.  The semiconductor layer  142  is formed on the gate insulating layer  141  to overlap with the gate electrode  140   a.  The source and drain electrodes  143   a  and  143   b  are formed on the semiconductor layer  142  to be spaced apart from each other. 
     An organic layer  144  formed of an acryl-based resin or the like is formed to cover the TFT. The organic layer  144  planarizes the lower flexible substrate  120   a  on which the TFT is formed. Although not shown, an inorganic layer (not shown) formed of SiO x , SiN x , or the like is formed between the gate insulating layer  141  and the organic layer  144 . The inorganic layer may improve the stability of an interface between the organic layer  144  and each of the gate insulating layer  141 , the source electrode  143   a,  and the drain electrode  143   b.    
     The second electrode  148  is formed on the organic layer  144  to cover the first electrode  145  connected to the drain electrode  143   b,  a bank insulating layer  146  that partially exposes the first electrode  145 , and the organic EML  147  formed on the exposed portion of the first electrode  145 . The bank insulating layer  146  defines a light-emitting region of the OLED array  140  and prevents light leakage of a non-light-emitting region. 
     Referring back to  FIG. 1 , a passivation layer  150  is formed to cover the OLED array  140 . The passivation layer  150  may have a single layer structure of an inorganic insulator, such as aluminum oxide (AlO x ), silicon oxynitride (SiON), silicon nitride (SiN x ), or silicon oxide (SiO x ) or an organic insulator such as benzocyclobutene or photoacryl. Alternatively, the passivation layer  150  may have a structure in which layers respectively formed of the inorganic insulator and the organic insulator are stacked one upon another. 
     Although not shown, a drive IC is formed at one side of the lower flexible substrate  120   a,  and the drive IC is connected to a printed circuit board (PCB). The PCB includes a timing control unit (not shown) for supplying various control signals to drive the OLED array  140  and a power supply (not shown) to supply a driving voltage. A signal of the PCB is applied to the OLED array  120   a  via the drive IC. 
     In particular, the PCB is integrally formed with a flexible PCB (FPCB) including a touch controller to drive the touch array  160 . The FPCB is electrically connected to the touch array  160  via an anisotropic conductive paste (ACP), which will be described below. 
     The touch array  160  formed on the upper flexible substrate  120   b  is adhered to the passivation layer  150  by an adhesive layer  170  so that the touch array  160  and the OLED array  140  face each other. In this regard, the upper flexible substrate  120   b  is a plastic film formed of at least one organic material selected from PEN, PET, polyethylene ether phthalate, polycarbonate, polyarylate, polyether imide, polyether sulfonate, polyimide, and polyacrylate, like the lower flexible substrate  120   a.    
     In particular, as illustrated in  FIG. 2B , the touch array  160  formed on the upper flexible substrate  120   b  includes a plurality of X electrodes  161   a  and a plurality of Y electrodes  161   b  that cross each other with a first insulating layer  162   a  positioned therebetween and take the form of a bar and a second insulating layer  162   b  to cover the Y electrodes  161   b.    
     The X and Y electrodes  161   a  and  161   b  of the touch array  160  are connected to pad parts by routing lines. In this regard, the pad parts are voltage applying pads or voltage detection pads. The touch array  160  is of a mutual capacitive type in which a driving voltage is applied to the X electrodes  161   a  and the Y electrodes  161   b  sense voltage drop according to whether touch is performed or not. 
     In some embodiments, the touch array  160  may include bridge electrodes formed on the upper flexible substrate  120   b,  a first insulating layer covering the bridge electrodes, X electrodes formed on the first insulating layer and electrically connected via the bridge electrodes, Y electrodes formed at the same layer level as the X electrodes, and a second insulating layer covering the X and Y electrodes. 
     Referring back to  FIG. 1 , the adhesive layer  170  is formed on the touch array  160 . In addition, the adhesive layer  170  is attached to the passivation layer  150 . In such a manner, the upper and lower flexible substrates  120   b  and  120   a  are adhered such that the touch array  160  and the OLED array  140  face each other. 
     Although not shown, the touch array  160  and the OLED array  140  are electrically connected to each other via an ACP. The ACP has a structure in which conductive balls coated with a metal such as gold (Au), silver (Ag), copper (Cu), molybdenum (Mo), or the like are dispersed in a sealant. 
     The ACP connects the pad parts of the touch array  160  to the FPCB. The pad parts are connected to X and Y electrodes  161   a  and  161   b  of the touch array  160  via routing lines. 
     In general, an FPCB to drive a touch array is separately formed from a PCB to drive an OLED array. However, in embodiments, the PCB to drive the OLED array  130  is integrally formed with the FPCB to drive the touch array  160 , and the FPCB and the touch array  160  are connected to each other using an ACP. 
     Therefore, in the OLED display device having a built-in touch panel, manufacturing costs may be reduced by integrating the FPCB to drive the touch array  160  with the PCB to drive the OLED array  140 . 
     In addition, a top cover  180  is attached to a rear surface of the upper flexible substrate  120   b  on which the touch array  160  is formed. The top cover  180  is formed of a material having high transmittance and flexibility, such as polymethylmethacrylate (PMMA), polyurethane (PU), acryl, cyclo olefin polymer (COP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide, or the like. 
     In addition, although not shown, a bottom cover formed of a material, such as PMMA, PU, acryl, COP, PET, PEN, polyimide, or the like may be formed on a rear surface of the lower flexible substrate  120   a.    
     As described above, the OLED array  140  and the touch array  160  are respectively formed on the lower flexible substrate  120   a  and the upper flexible substrate  120   b,  and thus the OLED display device having a built-in touch panel has flexibility. In particular, a flexible substrate has a smaller thickness than a general rigid substrate and thus may enable reduction in display device thickness. 
     Moreover, the FPCB for driving the touch array  160  is formde on the PCB for driving the OLED array  140  and the FPCB is electrically connected to the touch array  160  via an ACP, and thus manufacturing costs may be reduced. 
     Hereinafter, a method of manufacturing the OLED display device having a built-in touch panel will be described in detail with reference to the accompanying drawings. 
     First Embodiment 
       FIGS. 3A through 3H  are sectional views sequentially illustrating a method of manufacturing the OLED display device having a built-in touch panel, according to a first embodiment of the present invention.  FIG. 4A  is a photograph of the upper flexible substrate  120   b  from which an upper exfoliation layer  110   b  is separated upon ultraviolet irradiation.  FIGS. 4B and 4C  are photographs showing a case in which wiring defects of the touch array  160  do not occur when the upper exfoliation layer is separated using ultraviolet irradiation. 
     As illustrated in  FIG. 3A , a lower exfoliation layer  110   a  is formed on a lower rigid substrate  100   a  such as a glass substrate, and the lower flexible substrate  120   a  is formed on the lower exfoliation layer  110   a.  The lower flexible substrate  120   a  is a plastic film formed by coating the lower exfoliation layer  110   a  with a polymer solution by slit coating, spin coating, or the like and curing the polymer solution coated thereon. 
     The plastic film is formed of at least one organic material selected from PEN, PET, polyethylene ether phthalate, polycarbonate, polyarylate, polyether imide, polyether sulfonate, polyimide, and polyacrylate. 
     As illustrated in  FIG. 3B , the buffer layer  130  is formed on the lower flexible substrate  120   a.  The buffer layer  130  improves adhesion between the lower flexible substrate  120   a  and the OLED array  140 , which will be described below and prevents moisture or impurities from diffusing into the OLED array  140  from the lower flexible substrate  120   a.  The buffer layer  130  may have a single layer structure of an inorganic insulator such as SiO x , SiN x , or the like or a double-layered structure including two layers of SiO x  and SiN x . 
     Subsequently, as illustrated in  FIG. 3C , the OLED array  140  is formed on the buffer layer  130 , and the passivation layer  150  is formed on the OLED array  140 . In particular, the OLED array  140  includes a TFT including a gate electrode, a gate insulating layer, a semiconductor layer, and source and drain electrodes and an OLED including a first electrode, an organic EML, and a second electrode. 
     First, the gate electrode is formed on the buffer layer  130 , and the gate insulating layer is formed to cover the gate electrode. In addition, the semiconductor layer is formed on the gate insulating layer to overlap with the gate electrode, and the source and drain electrodes spaced apart from each other are formed on the semiconductor layer. 
     The organic layer  144  formed of an acryl-based resin or the like is formed to cover the TFT. The organic layer  144  planarizes the lower flexible substrate  120   a  on which the TFT is formed. Although not shown, an inorganic layer formed of SiO x , SiN x , or the like is formed between the gate insulating layer and the organic layer  144  and thus may improve the stability of an interface between the organic layer  144  and each of the gate insulating layer, the source electrode, and the drain electrode. 
     The second electrode is formed on the organic layer  144  to cover the first electrode connected to the drain electrode, a bank insulating layer that partially exposes the first electrode, and the organic EML formed on the exposed portion of the first electrode. The bank insulating layer defines a light-emitting region of the OLED array  140  and prevents light leakage of a non-light-emitting region. 
     Next, the passivation layer  150  is formed on the OLED array  140 . The passivation layer  150  may have a single layer structure of an inorganic insulator, such as AlO x , SiON, SiN x , or SiO x  or an organic insulator such as benzocyclobutene or photoacryl. Alternatively, the passivation layer  150  may have a structure in which layers respectively formed of the inorganic insulator and the organic insulator are stacked one upon another. 
     Subsequently, as illustrated in  FIG. 3D , the touch array  160  is formed on the upper flexible substrate  120   b.  In this regard, the upper flexible substrate  120   b  is a plastic film formed by coating the upper exfoliation layer  110   b  formed on an upper rigid substrate  100   b  formed of glass with the above-described polymer by slit coating, spin coating, or the like and curing the polymer coated on the upper exfoliation layer  110   b.    
     Next, the touch array  160  is formed on the upper flexible substrate  120   b.  The touch array  160  is formed such that a plurality of X electrodes and a plurality of Y electrodes that cross each other with a lower insulating layer positioned therebetween and take the form of a bar are formed on the upper flexible substrate  120   b  and an upper insulating layer is formed to cover the Y electrodes. The X and Y electrodes are connected to pad parts by routing lines, and the pad parts are voltage applying pads or voltage detection pads. 
     The touch array  160  is of a mutual capacitive type in which a driving voltage is applied to the X electrodes and the Y electrodes sense voltage drop according to whether touch is performed or not. 
     In some embodiments, the touch array  160  may include bridge electrodes formed on the upper flexible substrate  120   b,  an insulating layer covering the bridge electrodes, X electrodes formed on the insulating layer and electrically connected via the bridge electrodes, and Y electrodes formed at the same layer level as the X electrodes. 
     Next, as illustrated in  FIG. 3E , the adhesive layer  170  is formed on the touch array  160 , and the adhesive layer  170  is attached to the passivation layer  150 . The lower and upper rigid substrates  100   a  and  100   b  are adhered by curing the adhesive layer  170  so that the touch array  160  and the OLED array  140  face each other. 
     Subsequently, as illustrated in  FIG. 3F , an ultraviolet irradiator is positioned above the upper rigid substrate  100   b,  and the upper rigid substrate  100   b  is irradiated with ultraviolet light. The upper exfoliation layer  110   b  loses adhesive strength upon ultraviolet irradiation and thus, as illustrated in  FIG. 4A , the upper exfoliation layer  110   b  is separated from a rear surface of the upper flexible substrate  120   b  via ultraviolet irradiation. In this regard, as illustrated in  FIGS. 4B and 4C , routing lines of the touch array  160  are not disconnected. 
     Although not shown, the lower rigid substrate  100   a  is cut on a unit panel basis, and then the PCB for driving the OLED array  140  is integrally formed with the FPCB for driving the touch array  160 . In addition, the FPCB is connected to the touch array  160  using an ACP. In this regard, the ACP has a structure in which conductive balls coated with a metal such as Au, Ag, Cu, Mo, or the like are dispersed in a sealant. 
     Subsequently, as illustrated in  FIG. 3G , an ultraviolet irradiator is positioned below the lower rigid substrate  100   a,  and then the lower rigid substrate  100   a  is irradiated with ultraviolet light. As with the upper exfoliation layer  110   b,  the lower exfoliation layer  110   a  also loses adhesive strength upon ultraviolet irradiation and thus is separated from a rear surface of the lower flexible substrate  120   a  by the irradiated ultraviolet light. 
     That is, in the OLED display device having a built-in touch panel described above, after removal of the upper rigid substrate  100   b,  the OLED array  140  and the touch array  160  are cut on a unit panel basis and then the lower rigid substrate  100   a  is removed. In another embodiment, however, after removal of the lower rigid substrate  100   a,  the OLED array  140  and the touch array  160  may be cut on a unit panel basis and then the upper rigid substrate  100   b  may be removed. 
     As described above, the lower and upper rigid substrates  100   a  and  100   b  are separately removed. This is because when the PCB for driving the OLED array  140 , the ACP, and the like are attached to the lower and upper flexible substrates  120   a  and  120   b  in a case in which only the lower and upper flexible substrates  120   a  and  120   b  remain, the lower and upper flexible substrates  120   a  and  120   b  may bend, resulting in poor attachment. 
     Lastly, as illustrated in  FIG. 3H , the top cover  180  is attached to the rear surface of the upper flexible substrate  120   b.  The top cover  180  is formed of a material having high transmittance and flexibility, such as PMMA, PU, acryl, COP, PET, PEN, polyimide, or the like. 
     In addition, although not shown, a bottom cover may be formed on a rear surface of the lower flexible substrate  120   a.  The bottom cover is formed of a material such as PMMA, PU, acryl, COP, PET, PEN, polyimide, or the like. 
     Second Embodiment 
     In a manufacturing method of the OLED display device having a built-in touch panel, according to a second embodiment of the present invention, an exfoliation layer formed between a rigid substrate and a flexible substrate is formed of a metal or a transparent conductive oxide and thus, when a high voltage is applied to the exfoliation layer, the exfoliation layer is separated from the flexible substrate. 
       FIGS. 5A through 5F  are sectional views sequentially illustrating a method of manufacturing the OLED display device having a built-in touch panel, according to a second embodiment of the present invention.  FIG. 6A  is a photograph of an upper flexible substrate  200   b  from which an upper exfoliation layer  210   b  is separated by application of a certain voltage.  FIGS. 6B and 6C  are photographs showing a case in which wiring defects of the touch array  160  do not occur when the upper exfoliation layer  210   b  is separated by application of a certain voltage. 
     As illustrated in  FIG. 5A , a lower exfoliation layer  210   a  is formed on a lower rigid substrate  200   a  formed of, for example, glass, and a lower flexible substrate  220   a  is formed on the lower exfoliation layer  210   a.  In this regard, the lower exfoliation layer  210   a  is formed of a metal such as molybdenum (Mo), aluminum (Al), or the like, or a transparent conductive oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), or the like. 
     The lower exfoliation layer  210   a  is used to separate the lower rigid substrate  200   a  from the lower flexible substrate  220   a.  In this regard, when the thickness of the lower exfoliation layer  210   a  is too small or too large, separation characteristics deteriorate when the lower exfoliation layer  210   a  is separated from the lower flexible substrate  220   a.  Thus, the thickness of the lower exfoliation layer  210   a  may range from 1,000 Å to 3,000 Å. 
     The lower flexible substrate  220   a  is formed on the lower exfoliation layer  210   a,  and an OLED array  240  is formed on the lower flexible substrate  220   a,  with a buffer layer  230  positioned therebetween. 
     The OLED array  240  includes a TFT and an OLED connected to the TFT. The TFT includes a gate electrode, a gate insulating layer, a semiconductor layer, and source and drain electrodes, and the OLED includes a first electrode, an organic EML, and a second electrode. A passivation layer  250  is formed on the OLED array  240 . 
     Subsequently, as illustrated in  FIG. 5B , a touch array  260  is formed on the upper flexible substrate  220   b.  In this regard, as with the lower flexible substrate  220   a,  an upper exfoliation layer  210   b  is formed on an upper rigid substrate  200   b  formed of, for example, glass. The upper exfoliation layer  210   b  is also formed of a metal such as Mo, Al, or the like, or a transparent conductive oxide such as ITO, IZO, ITZO, or the like. The thickness of the upper exfoliation layer  210   b  ranges from 1,000 Å to 3,000 Å. 
     Next, the upper exfoliation layer  210   b  is coated with the above-described polymer using a method such as slit coating, spin coating, or the like and the polymer coated on the upper exfoliation layer  210   b  is cured, to form the upper flexible substrate  220   b.  Subsequently, the touch array  260  is formed on the upper flexible substrate  220   b.  The touch array  260  includes a plurality of X electrodes and a plurality of Y electrodes that cross each other with a lower insulating layer positioned therebetween and take the form of a bar, and an upper insulating layer to cover the Y electrodes. The X and Y electrodes are connected to pad parts, such as voltage applying pads or voltage detection pads, by routing lines. 
     In some embodiments, the touch array  260  may include bridge electrodes formed on the upper flexible substrate  220   b,  an insulating layer to cover the bridge electrodes, X electrodes formed on the insulating layer and electrically connected via the bridge electrodes, and Y electrodes formed at the same layer level as the X electrodes. 
     Next, as illustrated in  FIG. 5C , an adhesive layer  270  is formed on the touch array  260 , and the adhesive layer  270  is attached to the passivation layer  250 . Then, the lower and upper rigid substrates  200   a  and  200   b  are adhered by curing the adhesive layer  270  so that the touch array  260  and the OLED array  240  face each other. 
     Subsequently, a high voltage, i.e., 3 kV to 5 kV, is applied to the upper exfoliation layer  210   b  using a voltage applying device. In this regard, the voltage is applied for a period on the order of a microsecond, and thus the high voltage applied to the upper exfoliation layer  210   b  is a pulse type voltage. Due to this, as illustrated in  FIG. 5D , a gap is formed between the upper exfoliation layer  210   b  formed of a metal or a transparent conductive oxide and the upper flexible substrate  220   b  formed of a plastic film. Thus, as illustrated in  FIG. 6A , the upper exfoliation layer  210   b  is separated from a rear surface of the upper flexible substrate  220   b.  In this regard, as illustrated in  FIGS. 6B and 6C , routing lines of the touch array  260  are not disconnected. 
     Although not shown, the lower rigid substrate  200   a  is cut on a unit panel basis, a PCB for driving the OLED array  240  is integrally formed with an FPCB for driving the touch array  260 , and the FPCB is connected to the touch array  260  using an ACP. 
     Subsequently, a pulse type high voltage ranging from 3 kV to 5 kV is also applied to the lower exfoliation layer  210   a.  As illustrated in  FIG. 5E , when the voltage is applied to the lower exfoliation layer  210   a,  a gap is formed between the lower exfoliation layer  210   a  formed of a metal or a transparent conductive oxide and the lower flexible substrate  220   a  formed of a plastic film. Accordingly, the lower exfoliation layer  210   a  is separated from the lower flexible substrate  220   a.    
     Next, as illustrated in  FIG. 5F , a top cover  280  is attached to a rear surface of the upper flexible substrate  220   b  from which the upper exfoliation layer  210   a  has been separated. The top cover  280  is formed of a material such as PMMA, PU, acryl, COP, PET, PEN, polyimide, or the like. Although not shown, a bottom cover may be formed on a rear surface of the lower flexible substrate  220   a.    
     According to the manufacturing method of the OLED display device having a built-in touch panel, a flexible substrate is formed on a rigid substrate with an exfoliation layer positioned therebetween, and an OLED array or a touch array is formed on the flexible substrate. In addition, the rigid substrate is separated from the flexible substrate using ultraviolet light. Therefore, an OLED display device including a built-in touch panel and having flexibility may be manufactured. 
     In particular, the OLED display device may be manufactured by integrating a PCB for driving the OLED array with an FPCB for driving the touch array, and thus manufacturing costs may be reduced. 
     As is apparent from the above description, the OLED display device having a built-in touch panel and the manufacturing method thereof have the following effects. 
     First, an OLED array and a touch array are formed on respective flexible substrates, and thus the OLED display device having a built-in touch panel has flexibility and decreased thickness. 
     Second, an FPCB for driving the touch array and a PCB for driving the OLED array are integrally installed, and thus manufacturing costs may be reduced. 
     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 inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.