Patent Publication Number: US-10332952-B2

Title: Display unit, method of manufacturing display unit, and electronic apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional claiming the benefit under 35 U.S.C. § 120 of U.S. application Ser. No. 15/797,300, entitled “METHOD OF MANUFACTURING DISPLAY UNIT WITH A SECOND ELECTRODE FORMED TO EXTEND ACROSS A BEZEL REGION,” filed Oct. 30, 2017, which is a divisional claiming the benefit under 35 U.S.C. § 120 of U.S. application Ser. No. 14/745,841, entitled “DISPLAY UNIT, METHOD OF MANUFACTURING DISPLAY UNIT, AND ELECTRONIC APPARATUS,” filed on Jun. 22, 2015, which claims the benefit of Japanese Priority Patent Application JP 2014-244946, filed Dec. 3, 2014, each of which is incorporated herein by reference. 
    
    
     BACKGROUND 
     The present disclosure relates to a display unit including a light emitting element such as an organic electroluminescence (EL) element, to a method of manufacturing such a display unit, and to an electronic apparatus including such a display unit. 
     In a display unit using a light emitting element such as an organic EL element, typically, an interlayer insulating film (an organic insulating film) is so provided as to cover a thin film transistor (TFT). The organic insulating film allows water to easily pass therethrough. Therefore, moisture infiltrates through the organic insulating film from outside, which causes deterioration of an organic layer of the organic EL element. This results in deterioration of light emission luminance or light emission defect such as occurrence of dark spots, which may cause degradation of reliability with time. 
     Therefore, an organic EL display unit having a structure in which a separation groove is provided on the organic insulating film as described above to separate the organic insulating film into a display region and an outer region, or a structure in which an end of the organic insulating film is selectively removed to separate the organic insulating film into the display region and the outer region, in a peripheral region (a bezel region) of the display region, has been proposed (For example, Japanese Unexamined Patent Application Publication Nos. 2004-281380, 2006-54111, 2008-283222, 2012-150901). By these methods, diffusion of moisture from outside to the display region through the organic insulating film is suppressed. 
     SUMMARY 
     However, in the element structure described in the above-described patent literatures, a second electrode (a cathode electrode) of the organic EL element is formed of a metal easily deteriorated by moisture, such as magnesium (Mg), calcium (Ca), and sodium (Na), or an alloy including such a metal. Therefore, the second electrode is provided in a predetermined region in order not to be deteriorated by moisture diffused through the organic insulating film or external environment of the display unit. For example, the second electrode may be provided inside the above-described separation groove of the organic insulating film or inside a region selectively removed, in order not to be exposed to the panel end surface. Specifically, the second electrode is formed with use of a so-called area mask. 
     When the area mask is used, a margin (a film formation margin) is secured in consideration of misalignment of the area mask (mask misalignment), leakage of a material, processing accuracy of a taper region or the mask, etc. Therefore, a peripheral region is increased, and it is thus difficult to achieve reduction in size of the bezel, reduction in size of the display panel, or reduction in cost of the display panel. 
     Accordingly, the second electrode is desirably formed without using the area mask as described above, to achieve an element structure that is adapted to suppress degradation of yield while achieving narrow bezel. 
     It is desirable to provide a display unit that is adapted to suppress degradation of yield while achieving narrow bezel, a method of manufacturing the display unit, and an electronic apparatus including the display unit. 
     According to an embodiment of the technology, there is provided a display unit including a display panel including a display region and a terminal region on a first substrate, the display region including a plurality of pixels, each of the plurality of pixels including a light emitting element, and the terminal region including a plurality of terminals at a part of a peripheral region of the display region. The light emitting element includes a first electrode, an organic layer, and a second electrode that is provided commonly to the plurality of pixels, in order from the first substrate side. The second electrode extends, continuously in a plan view, to an end of the first substrate in a region on the first substrate except for the terminal region, and is configured to be electrically disconnected from an exterior member of the display panel. 
     According to an embodiment of the technology, there is provided an electronic apparatus provided with a display unit. The display unit includes a display panel including a display region and a terminal region on a first substrate, the display region including a plurality of pixels, each of the plurality of pixels including a light emitting element, and the terminal region being provided at a part of a peripheral region of the display region and including a plurality of terminals. The light emitting element includes a first electrode, an organic layer, and a second electrode in order from the first substrate side, the second electrode being provided commonly to the plurality of pixels. The second electrode extends, continuously in a plan view, to an end of the first substrate in a region on the first substrate except for the terminal region, and is configured to be electrically disconnected from an exterior member of the display panel. 
     In the display unit and the electronic apparatus according to the respective embodiments of the disclosure, the second electrode extends, continuously in a plan view, to the end of the first substrate in the region of the first substrate except for the terminal region. Specifically, in the manufacturing process, for example, the second electrode may be formed without using a film formation mask or with use of a mask that has an opening and selectively shields only the terminal region. Therefore, in the peripheral region except for the terminal region, it is unnecessary to secure the film formation margin in consideration of misalignment of the mask opening position in the formation of the second electrode. On the other hand, it is concerned that electrical short circuit between the second electrode extended to the end of the first substrate and the exterior member of the display panel occurs. However, since the second electrode is so configured as to be electrically disconnected from the exterior member of the display panel, such short circuit is difficult to occur after the display panel is mounted on the exterior member. Therefore, it is unnecessary to secure the film formation margin in the peripheral region on the first substrate in the formation of the second electrode, and therefore, the peripheral region is decreased in size as compared with a case where the second electrode is formed in a selective region with use of a mask. 
     According to an embodiment of the technology, there is provided a method of manufacturing a display unit. The method includes: forming a display panel including a display region and a terminal region, the display region including a plurality of pixels, each of the plurality of pixels including a light emitting element, and the terminal region including a plurality of terminals at a part of a peripheral region of the display region; and forming, as the light emitting element, a first electrode, an organic layer, and a second electrode on the first substrate, the second electrode being common to the plurality of pixels. The second electrode is formed to extend, continuously in a plan view, to an end of the first substrate in a region on the first substrate except for the terminal region, and is formed to be electrically disconnected from an exterior member of the display panel. 
     In the method of manufacturing the display unit according to the embodiment of the disclosure, the second electrode is formed to extend, continuously in a plan view, to the end of the first substrate in the region of the first substrate except for the terminal region. In other words, for example, the second electrode is formed without using a film formation mask or with use of a mask that has an opening and selectively shields only the terminal region. Therefore, in the peripheral region except for the terminal region, it is unnecessary to secure the film formation margin in consideration of misalignment of the mask opening position and the like in the formation of the second electrode. On the other hand, it is concerned that electrical short circuit between the second electrode extended to the end of the first substrate and the exterior member of the display panel occurs. However, since the second electrode is so configured as to be electrically disconnected from the exterior member of the display panel, such short circuit is difficult to occur after the display panel is mounted on the exterior member. Accordingly, it is unnecessary to secure the film formation margin in the peripheral region on the first substrate in the formation of the second electrode, and therefore, the peripheral region is decreased in size as compared with the case where the second electrode is formed in a selective region with use of a mask. 
     In the display unit, the method of manufacturing the display unit, and the electronic apparatus according to the respective embodiments of the disclosure, the second electrode extends, continuously in a plan view, to the end of the first substrate in the region on the first substrate except for the terminal region. In other words, in the peripheral region except for the terminal region, the second electrode is formed without using a mask, and thus it is unnecessary to secure the predetermined film formation margin. Therefore, it is possible to reduce the peripheral region of the first substrate in size. Such a second electrode is exposed to the end surface of the display panel, but the second electrode is so configured as to be electrically disconnected from the exterior member. Therefore, it is possible to suppress occurrence of electrical short circuit, and to suppress degradation of yield after the display panel is mounted on the exterior member. As a result, it becomes possible to suppress degradation of yield while achieving narrow bezel. 
     Note that the above-described contents are examples of the disclosure. Effects achieved by the disclosure are not limited to those described above, and effects achieved by the disclosure may be effects other than those described above or may further include other effects. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the technology as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the specification, serve to explain the principles of the technology. 
         FIG. 1  is a plan view illustrating a configuration of a display unit according to a first embodiment of the disclosure. 
         FIG. 2  is a diagram illustrating a sectional structure along IA-IA line illustrated in  FIG. 1 . 
         FIG. 3  is a diagram illustrating a sectional structure along IB-IB line illustrated in  FIG. 1 . 
         FIG. 4  is a sectional diagram illustrating a state where the display unit illustrated in  FIG. 1  is mounted on an exterior frame. 
         FIG. 5A  is a plan view illustrating a structure of an area mask used in a step of forming a second electrode of the display unit illustrated in  FIG. 1 . 
         FIG. 5B  is a plan view illustrating a state where the area mask that is used in the step of forming the second electrode of the display unit illustrated in  FIG. 1  is disposed on a first substrate. 
         FIG. 6  is a diagram illustrating a sectional structure near a terminal part in the step of forming the second electrode. 
         FIG. 7  is a plan view illustrating a structure of an area mask used in a step of forming a second electrode of a display unit according to comparative example 1. 
         FIG. 8  is a sectional diagram illustrating a structure of the display unit fabricated with use of the area mask illustrated in  FIG. 7 . 
         FIG. 9  is a sectional diagram illustrating a structure of a display unit according to comparative example 2. 
         FIG. 10  is a plan view illustrating a configuration of a display unit according to a second embodiment of the disclosure. 
         FIG. 11  is a diagram illustrating a sectional structure along IIA-IIA line illustrated in  FIG. 10 . 
         FIG. 12  is a sectional diagram illustrating a structure of a display unit according to a third embodiment of the disclosure. 
         FIG. 13A  is a sectional diagram illustrating a structure example of a display unit according to a modification. 
         FIG. 13B  is a sectional diagram illustrating a structure example of a display unit according to another modification. 
         FIG. 13C  is a sectional diagram illustrating a structure example of a display unit according to still another modification. 
         FIG. 13D  is a sectional diagram illustrating a structure example of a display unit according to still another modification. 
         FIG. 14  is a schematic diagram for explaining a method of fabricating the display unit illustrated in  FIG. 13A . 
         FIG. 15A  is a perspective view illustrating a configuration of a smartphone. 
         FIG. 15B  is a perspective view illustrating the configuration of the smartphone. 
         FIG. 16A  is a diagram illustrating an appearance of a mobile phone. 
         FIG. 16B  is a diagram illustrating the appearance of the mobile phone. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, some embodiments of the disclosure will be described in detail with reference to drawings. Note that description will be given in the following order. 
     1. First embodiment (an example of a display unit in which an end of a second electrode is covered with a protection film) 
     2. Second embodiment (an example of a display unit having an inverse-tapered structure in a lower layer of a second electrode) 
     3. Third embodiment (an example of a display unit in which an outermost end of a second substrate overhangs from an end surface of a second electrode) 
     4. Modifications (other examples of shapes of an end surface of a substrate) 
     5. Application example (an example of electronic apparatus) 
     First Embodiment 
     [Configuration] 
       FIG. 1  illustrates a planer configuration of a display unit (a display unit  1 ) according to a first embodiment of the disclosure. The display unit  1  may be, for example, an organic EL display unit, and includes a display panel  10  in a display region  1 A on a first substrate (a first substrate  11  described later). The display panel  10  may include, for example, a plurality of pixels (sub-pixels) P that may be arranged in matrix. Each of the pixels P includes an organic EL element, and may emit red light (wavelength of about 620 nm to about 750 nm), green light (wavelength of about 495 nm to about 570 nm), blue light (wavelength of 450 nm to 495 nm), or white light. One pixel is configured of sub-pixels of four colors. A signal line drive circuit, a scan line drive circuit, a power line drive circuit, and the like that are used to drive the pixels P are provided in a peripheral region (a bezel region  1 B) of the display region  1 A. A terminal part  1 C (a terminal region) including a plurality of terminals (terminals  22 ) for external connection is provided at a part of the bezel region  1 B. 
       FIG. 2  illustrates a sectional structure along IA-IA line of the display unit illustrated in  FIG. 1 .  FIG. 3  illustrates a sectional structure along IB-IB line of the display unit illustrated in  FIG. 1 . The display unit  1  is configured by bonding a second substrate (an opposing substrate, a sealing substrate)  20  on a first substrate (a element substrate)  11  with the organic EL elements in between, and is a top emission display unit emitting light that has passed through the second substrate  20 . 
     A circuit layer  12  provided with a pixel circuit that includes a thin film transistor (TFT) is provided on the first substrate  11  of the display unit  1 , and a surface of the circuit layer  12  is covered with a planarizing film  13  (correlation insulating film). A first electrode (for example, an anode)  14  of the organic EL element is provided on the planarizing film  13 . The first electrode  14  is electrically connected to the TFT provided in the circuit layer  12 . An organic insulating film  15  (a pixel separation film), an organic layer  16  including a light emitting layer, a second electrode  17 , and a protection film  18  are provided in order on the first electrode  14 . A seal layer  19 A and a filler layer  19 B are provided as a sealing layer on the protection film  18 , and the second substrate  20  is bonded thereto. 
     A configuration of each section of the display unit  1  is described below. 
     The first substrate  11  may be configured of, for example, glass, silicon, a resin, or the like. 
     The circuit layer  12  includes the TFT, and the TFT may be configured of, for example, a bottom-gate metal oxide semiconductor field effect transistor (MOSFET). The TFT may be configured of crystalline silicon, amorphous silicon, or the like, or may be configured of an oxide semiconductor. 
     The planarizing film  13  planarizes the surface of the circuit layer  12  to make the film thickness of each layer of the organic EL element formed thereon uniform. Examples of a material of the planarizing film  13  may include an organic insulating film made of a polyimide resin, an acrylic resin, a novolak resin, or the like. Alternatively, as the material of the planarizing film  13 , for example, an inorganic material such as a silicon oxide (SiO 2 ), silicon nitride (SiNx), and silicon oxynitride (SiON) may be used. 
     The first electrode  14  of the organic EL element is electrically separated for each pixel, and may have, for example, light reflection property. Examples of a material of the first electrode  14  may include a simple substance of a metal element such as chromium (Cr), gold (Au), platinum (Pt), nickel (Ni), copper (Cu), molybdenum (Mo), tungsten (W), titanium (Ti), tantalum (Ta), and silver (Ag), and an alloy thereof. 
     The organic insulating film  15  electrically separates the first electrode  14  for each pixel, and secures insulating property between the first electrode  14  and the second electrode  17 . The organic insulating film  15  has an opening for each pixel P, and forms a light emitting region of the organic EL element. The organic insulating film  15  may be formed of, for example, an organic insulating material such as a photosensitive resin. The organic insulating film  15  is so provided on the display region  1 A and the bezel region  1 B as to cover the peripheral circuits, and has a separation groove (a separation groove  15 A) in the bezel region  1 B. Moreover, the organic insulating film  15  is selectively removed in an outermost peripheral region of the bezel region  1 B. A width of the separation groove  15 A may be, for example, about 10 μm or larger and about 100 μm or lower, and a distance between an end  15   e  of the organic insulating film  15  and an end e 1  of the first substrate  11  (a width of a part where the organic insulating film  15  is removed) may be, for example, about 100 μm or larger and about 200 μm or lower. 
     The organic layer  16  includes a light emitting layer (an organic electroluminescence layer). Here, the organic layer  16  includes a white light emitting layer common to the organic EL elements. Incidentally, the organic layer  16  may include, for example, a hole transport layer (HTL), a hole injection layer (HIL), and an electron transport layer (ETL), in addition to the light emitting layer. Moreover, for example, an electron injection layer (EIL) such as LiF may be provided between the organic layer  16  and the second electrode  17 . The organic layer  16  is so formed as to cover the display region  1 A and a part of the bezel region  1 B, but is so formed as not to overlap with the separation groove  15 A. 
     The second electrode  17  has a light transmission property, is common to the organic EL elements (the pixels), and covers the display region  1 A. The second electrode  17  may desirably include a transparent conductive film made of, for example, ITO, IZO, or ZnO. The second electrode  17  is electrically connected to a wiring layer on the first electrode  11  through the cathode contact part  17 C. The second electrode  17  extends, continuously in a plan view, to the end e 1  of the first substrate  11  in a region except for the terminal part  1 C on the first substrate  11 , and is so configured as to be electrically disconnected from an exterior member (an exterior frame  24 ) of the display panel  10 . 
     In the first embodiment, the second electrode  17  is substantially uniformly formed to cover the entire surface except for the terminal part  1 C. The second electrode  17  covers the separation groove  15 A, the cathode contact part  17 C, the organic insulating film  15 , and the end  15   e  thereof. Moreover, an end surface protection film  21  (an insulating film) is provided on an end surface of the display panel  10  to cover the end  17   e  of the second electrode  17 . Here, for example, in a plan view, the terminal part  1 C may be provided in a region corresponding to one side of the rectangular display panel  10  (the first substrate  11 ), and the end surface protection film  21  may be provided on ends (end surfaces) corresponding to three sides except for the one side provided with the terminal part  1 C. Incidentally, as illustrated in  FIG. 3 , a part (a separation groove  15 B) where the organic insulating film  15  and the planarizing film  13  are selectively removed is provided outside the separation groove  15 A in the region provided with the terminal part  1 C on the first substrate  11 . 
       FIG. 4  illustrates a state where the display panel  10  is mounted on the exterior frame  24 . In this way, the end surface protection film  21  is provided to cover an end of an element layer  23  in the structure in which the element layer  23  including the above-described organic EL element is sealed between the first substrate  11  and the second substrate  20 . The exterior frame  24  may be formed of, for example, a metal, and is so attached as to cover the end of the display panel  10 . The exterior frame  24  is not in contact with the element layer  23  including the second electrode  17 , by the end surface protection film  21 . 
     The cathode contact part  17 C is provided in a region of the bezel region  1 B corresponding to the separation groove  15 C. In the selective region on the cathode contact part  17 C, the planarizing film  13  is removed. A width of the cathode contact part  17 C is set based on a cathode current amount corresponding to the size of the display unit  1  and a contact resistance of the contact electrode. 
     The protection film  18  is so provided on the second electrode  17  as to cover the entire surface of the display region  1 A and the bezel region  1 B (except for the terminal part  1 C). The protection film  18  may be formed of, for example, an inorganic material such as silicon oxide (SiOx), silicon nitride (SiNx), a silicon oxynitride (SiNxOy), titanium oxide (TiOx), and aluminum oxide (AlxOy). 
     Here, since the separation groove  15 A and the end  15   e  of the organic insulating film  15  are covered with the second electrode  17  and the protection film  18 , it is possible to suppress moisture infiltration from the outside of the display panel  10  and to prevent infiltration of moisture to the organic layer  16 , as compared with a case where the separation groove  15 A and the end  15   e  of the organic insulating film  15  are covered with only the protection film  18 . Therefore, it is possible to improve reliability while suppressing degradation of the organic EL element. 
     The seal layer  19 A is provided in the bezel region  1 B on the first substrate  11 , and may be formed of, for example, an epoxy resin or an acrylic resin. The filler layer  19 B is provided in a region surrounded by the seal layer  19 A, and functions as an adhesive layer. The filler layer  19 B may be formed of, for example, an epoxy resin or an acrylic resin. 
     The second substrate  20  may be formed of, for example, glass, and a color filter and a light shielding layer (both not illustrated) may be provided in the display region  1 A of the second substrate  20 . The light shielding layer is provided also in the bezel region  1 B. 
     The end surface protection film  21  is configured of an inorganic insulating film, an organic insulating film, or a stacked layer film thereof. Examples of the inorganic insulating film may include a silicon oxide, a silicon nitride, a silicon oxynitride, a titanium oxide, and an aluminum oxide. Examples of the organic insulating film may include an epoxy resin and acrylic resin. 
     [Manufacturing Method] 
     The above-described display unit  1  may be manufactured in the following manner, for example. First, after the circuit layer  12  and the planarizing film  13  are formed on the first substrate  11 , the first electrode  14 , the organic insulating film  15 , the organic layer  16 , and the second electrode  17  are formed in order on the planarizing film  13 . 
     Here, to form the second electrode  17 , a film may be formed by, for example, a sputtering method with use of a mask  110  (a film formation mask, an area mask) having openings  110   a , for example, as illustrated in  FIG. 5A . The mask  110  is a so-called multiple-production mask that allows film formation over a region including the plurality of display regions  110  at a time. In the first embodiment, as illustrated in  FIG. 5B , the openings  110   a  of the mask  110  are disposed over the entire region of the first substrate  11  except for the terminal part  1 C. In other words, as also illustrated in  FIG. 6 , the second electrode  17  is formed while only the terminal part  1 C is selectively masked. Therefore, in the region on the first substrate  11  corresponding to the terminal part  1 C, a film formation margin M 1  may be preferably secured in consideration of misalignment of the position of the mask  110 . For example, when a space for formation of peripheral circuits and the like is secured in the terminal part  1 C, the film formation margin M 1  may be preferably secured in the terminal part  1 C. In addition, when the plurality of (three in this case) display regions  1 A are disposed along one direction on the first substrate  11 , one opening  110   a  is disposed with respect to the plurality of display regions  1 A. Specifically, the plurality of display regions  1 A are disposed so that the regions of the respective bezel regions  1 B except for the respective terminal parts  1 C are adjacent to one another, and the mask  110  that has the opening  110   a  larger than an opening  103   a  of a mask  103  in a comparative example 1 illustrated in  FIG. 7  is used. 
     By film formation with use of such a mask  110 , the second electrode  17  is formed to uniformly extend to the end e 1  of the first substrate  11  (is formed to be exposed to the end e 1  of the first substrate  11 ) in the region except for the terminal part  1 C. In addition, when the second electrode is formed with use of the mask  103  according to the comparative example, the opening  103   a  is disposed for each display region. Therefore, as illustrated in  FIG. 8 , a film formation margin M 101  may be desirably secured in a region between the separation groove  15 A and the end  15   e  in the bezel region  101 B even in the region other than the terminal part. Accordingly, it is difficult to reduce the size of the bezel region  101 B. In contrast, in the first embodiment, it is unnecessary to use the mask  103  as in the comparative example 1, and it is possible to form the second electrode  17  without considering the film formation margin by the mask in the region except for the terminal part  1 C. Accordingly, it is possible to achieve reduction in size of the bezel region  1 B. Moreover, since the terminal part  1 C is exposed without etching step, it is possible to simplify the process and to enhance working easiness and strength of the mask  110 . 
     Here, a transparent conductive film such as ITO may be desirably used as the second electrode  17 . The transparent conductive film is difficult to be deteriorated by moisture. Therefore, even in the case where the second electrode  17  is extended to the end e 1  of the first substrate  11 , infiltration of moisture to the organic layer  16  is suppressed to improve reliability. This is advantageous in reduction of the size of the bezel region  1 B. If the second electrode  17  is formed of a metal that is easily deteriorated by moisture, such as magnesium (Mg), calcium (Ca), and sodium (Na), or an alloy thereof, it is concerned that reliability is deteriorated by moisture infiltration to the organic layer  16 . Therefore, as with the comparative example 1, the second electrode  17  may be desirably formed with use of the mask ( FIG. 7 ) having the opening for each display region, and as a result, it is necessary to secure the film formation margin M 101  ( FIG. 8 ). In addition, it is necessary to secure the sufficiently large width of the contact part between the second electrode  17  and the cathode contact part  17 C in consideration of the film formation margin M 101 . Therefore, it is necessary to secure the wide bezel region  101 B, and thus it is difficult to achieve reduction in size of the bezel, reduction in size of the display unit, or reduction in cost of the display unit. 
     After the formation of the second electrode  17  as described above, the protection film  18  is formed and the second substrate  20  is bonded thereon with the seal layer  19 A and the filler layer  19 B in between. After that, the first substrate  11  and the second substrate  20  that have been bonded to each other are scribed and broken to be divided into the plurality of display panels  10 . At this time, in the bezel region  1 B of the display panel  10  except for the terminal part  1 C, division is performed at the position not overlapping with the end  15   e  of the organic insulating film  15 . On the other hand, in the terminal part  1 C of the first substrate  11 , the division is performed while the scribing position of the first substrate  11  and the scribing position of the second substrate  20  are shifted from each other so that the terminal  22  is exposed. Subsequently, the protection film  18  formed on the terminal part  1 C is removed by etching to expose the terminal part  1 C. Finally, the end surface protection film  21  is so formed on the end e 1  of the first substrate  11  as to cover the end  17   e  of the second electrode  17 . In this way, the display unit  1  is completed. 
     [Function and Effects] 
     In the display unit  1  according to the first embodiment, the second electrode  17  extends, continuously in a plan view, to the end e 1  of the first substrate  11  in the region on the first substrate  11  except for the terminal part  1 C. Specifically, in the manufacturing process, the second electrode  17  is formed without using the area mask having the openings disposed for the respective display regions or with use of the mask  110  that has the openings  110   a  and selectively shields only the terminal part  1 C. Therefore, in the bezel region  1 B except for the terminal part  1 C, it is unnecessary to secure the film formation margin in consideration of misalignment of the position of the mask openings in the formation of the second electrode  17 . 
     On the other hand, the second electrode  17  extends to the end of the first substrate  11 , which may cause the second electrode  17  to contact with the metal exterior frame  24 , for example, as with a comparative example 2 illustrated in  FIG. 9 , and thus occurrence of electrical short circuit X 1  is concerned. This may cause degradation of yield. In contrast, in the first embodiment, the end  17   e  of the second electrode  17  is so configured as to be electrically disconnected from the exterior frame  24  of the display panel  10 . Specifically, the end  17   e  of the second electrode  17  is covered with the end surface protection film  21 . Therefore, short circuit X 1  as in the comparative example 2 is difficult to occur after the display panel  10  is mounted on the exterior frame  24 . Therefore, in the bezel region  1 B of the first substrate  11 , it is possible to form the second electrode  17  without securing the film formation margin in the formation of the second electrode  17 , and thus the bezel region  1 B is reduced in size. 
     As described above, in the first embodiment, in the bezel region  1 B except for the terminal part  1 C, the second electrode  17  extends to the end e 1  of the first substrate  11 , which eliminates necessity of securing of the film formation margin in the formation of the second electrode  17 , and it is accordingly possible to reduce in size of the bezel region  1 B. Moreover, this causes downsizing and reduction in cost. Further, the end  17   e  of the second electrode  17  is covered with the end surface protection film  21 , which makes it possible to suppress occurrence of electrical short circuit after the display panel  10  is mounted on the exterior frame  24 . As a result, it is possible to suppress degradation of yield while reducing the size of the bezel. 
     Next, other embodiments and modifications of the disclosure are described. In the following description, like numerals are used to designate substantially like components of the above-described first embodiment, and the description thereof is appropriately omitted. 
     Second Embodiment 
       FIG. 10  illustrates a planar configuration of a display unit according to a second embodiment of the disclosure. The display unit may be, for example, an organic EL display unit similarly to the above-described first embodiment, and may include, for example, a display panel (a display panel  10 A) including a plurality of pixels (sub-pixels) P that are arranged in matrix, in the display region  1 A on the first substrate  11 . Moreover, the display unit is configured by bonding the second substrate  20  to the first substrate  11  with the organic EL elements in between, and is a top-emission display unit emitting light that has passed through the second substrate  20 . A signal line drive circuit, a scan line drive circuit, a power line drive circuit, and the like that are used to drive the pixels P are provided in the bezel region  1 B of the display region  1 A. The terminal part  1 C is provided on a part of the bezel region  1 B. 
       FIG. 11  illustrates a sectional structure along IIA-IIA line of the display unit illustrated in  FIG. 10 . Similar to the display panel  10  in the above-described first embodiment, also in the display panel  10 A, the circuit layer  12  including TFTs is provided on the first substrate  11 , and the surface thereof is covered with the planarizing film  13 . The first electrode  14  of the organic EL element is provided on the planarizing film  13 , and the organic insulating film  15 , the organic layer  16 , the second electrode  17 , and the protection film  18  are provided in order on the first electrode  14 . The seal layer  19 A and the filler layer  19 B are provided on the protection film  18 , and the second substrate  20  is bonded thereto. In such a structure, the second electrode  17  is formed to extend, continuously in a plan view, to the end e 1  of the first substrate  11 . In addition, the end  17   e  of the second electrode  17  is so configured as to be electrically disconnected from the exterior frame  24  (not illustrated in  FIG. 11 ). 
     However, in the second embodiment, a structure having an inverse-tapered shape (an inverse-tapered structure  25 ) is disposed on a lower layer of the second electrode  17 . Here, the inverse-tapered structure  25  is disposed to be adjacent to the lower surface of the second electrode  17 . 
     The second electrode  17  extends, continuously in a plan view, from the display region  1 A to the end e 1  of the first substrate  11 , but is electrically discontinuous by the inverse-tapered structure  25 . Specifically, in the second electrode  17 , a part (the display region  1 A side) inside the formation position of the inverse-tapered structure  25  is electrically separated from a part outside the formation position of the inverse-tapered structure  25 . 
     The inverse-tapered structure  25  is so disposed in the bezel region  1 B as to surround the display region  1 A. The inverse-tapered structure  25  may be formed of, for example, a photosensitive resin such as photoresist. 
     In the second embodiment, after the formation of the inverse-tapered structure  25 , the second electrode  17  is formed in a manner similar to the above-described first embodiment, namely, without using the area mask  103  as illustrated in  FIG. 7 . As a result, in the second electrode  17 , the part inside the inverse-tapered structure  25  and the part outside the inverse-tapered structure  25  are electrically separated from each other. Accordingly, when the end  17   e  of the second electrode  17  is in contact with the exterior frame after mounting, it is possible to prevent occurrence of electrical short circuit. Consequently, it is possible to obtain effects equivalent to those in the above-described first embodiment. 
     Third Embodiment 
       FIG. 12  illustrates a sectional structure of a display unit according to a third embodiment of the disclosure together with the exterior frame  24 . The display unit may be, for example, an organic EL display unit similarly to the above-described first embodiment, and although not illustrated in particular, the display unit includes a display panel (a display panel  10 B) that includes a plurality of pixels (sub-pixels) P arranged in matrix, in the display region  1 A on the first substrate  11 . Moreover, the display unit is configured by bonding the second substrate  20  to the first substrate  11  with the organic EL elements (the element layer  23 ) in between, and is a top emission display unit emitting light that has passed through the second substrate  20 . A signal line drive circuit, a scan line drive circuit, a power line drive circuit, and the like that are used to drive the pixels P are provided in the bezel region  1 B of the display region  1 A. The terminal part  1 C is provided in a part of the bezel region  1 B. Also, in the display panel  10 B, the second electrode  17  of the element layer  23  is formed to extend, continuously in a plan view, to the end e 1  of the first substrate  11 , similarly to the display panel  10  according to the above-described first embodiment. Further, the end  17   e  of the second electrode  17  is so configured as to be electrically disconnected from the exterior frame  24 . 
     Incidentally, in the third embodiment, the second electrode  17  is disposed inside the outermost end of one or both of the first substrate  11  and the second substrate  20 . Specifically, for example, in a region except for the terminal part  1 C, an end e 2  (the outermost end) of the second substrate  20  is so disposed as to overhang from the end e 1  of the first substrate  11  by a width d. In the manufacturing process, at the time of performing scribing and breaking after the first substrate  11  and the second substrate  20  are bonded to each other, a scribing position and a breaking position are set so that the second substrate  20  has an outer shape larger than that of the first substrate  11  in the region except for the terminal part  1 C. As a result, the end  17   e  of the second electrode  17  is disposed inside the outermost end of the display panel  10 B. Thus, the end e 2  of the second substrate  20  is in contact with the exterior frame  24  after mounting, and the end  17   e  of the second electrode  17  located inside the end e 2  of the second substrate  20  is not in contact with the exterior frame  24 . Accordingly, it is possible to prevent occurrence of electrical short circuit. Consequently, it is possible to obtain effects equivalent to those in the above-described first embodiment. 
     &lt;Modifications&gt; 
     Incidentally, the display panel in which the second electrode  17  is disposed inside the outermost end of one or both of the first substrate  11  and the second substrate  20  is not limited to the display panel  10 B according to the above-described third embodiment. For example, as illustrated in  FIG. 13A  to  FIG. 13D , one or both of the first substrate  11  and the second substrate  20  may each have a tapered end surface. Specifically, as illustrated in  FIG. 13A  and  FIG. 13D , both an end surface S 1  of the first substrate  11  and an end surface S 2  of the second substrate  20  may have a tapered shape. Alternatively, as illustrated in  FIG. 13B  and  FIG. 13C , only the end surface S 1  of the first substrate  11  may have a tapered shape. Note that the tapered shape as described above may be formed by shifting the scribing position and the breaking position. A distance d 1  between the scribing position and the breaking position may be desirably set to about 10 μm or larger and about 100 μm or lower. For example, the tapered shape illustrated in  FIG. 13A  may be formed by setting a scribing position Ps and a breaking position Pb as schematically illustrated in  FIG. 14 . 
     APPLICATION EXAMPLES 
     The display units described in the above-described embodiments and the modifications are applicable to electronic apparatuses in every field that display externally input picture signal or internally generated picture signal as a picture. Examples thereof are described below. 
       FIG. 15A  and  FIG. 15B  each illustrate an appearance of a smartphone  220 . The smartphone  220  may include, for example, a display section  221  and an operation section  222  on front side, and a camera  223  on back side, and the display unit according to any of the above-described embodiments and the like is mounted on the display section  221 . 
       FIG. 16A  and  FIG. 16B  each illustrate an appearance of a mobile phone  300 . The mobile phone may be configured by, for example, coupling an upper housing  310  and a lower housing  320  with a coupling section (a hinge section)  330 , and may include a display  340 , a sub-display  350 , a picture light  360 , and a camera  370 . The display unit according to any of the above-described embodiments and the like is mounted on the display  340  or the sub-display  350 . 
     Hereinbefore, although the disclosure has been described with referring to the embodiments and the modifications, the disclosure is not limited to the above-described embodiments and the like, and various modifications may be made. For example, in the above-described embodiments and the like, the structure in which the terminal part  1 C of the display panel is provided only in a region corresponding to one side of the bezel region  1 B on the first substrate  11  has been exemplified. Alternatively, the terminal part  1 C may be provided in a region corresponding to two or more sides of the bezel region  1 B. 
     Moreover, in the above-described embodiments and the like, the case where the organic EL display unit is of the top emission type has been described. However, the organic EL display unit is not limited thereto, and the contents of the disclosure may be applicable to, for example, a structure of bottom emission type. 
     Further, the material and the thickness of each layer described in the above-described embodiments and the like are not limited to those described, and other material and other thickness may be employed. In addition, the display unit does not necessarily have all of the layers described above, or may include other layers in addition to the layers described above. Further, the effects described in the above-described embodiments and the like are illustrative and non-limiting. Effects achieved by the disclosure may be effects other than those described above or may further include other effects. 
     Note that the disclosure may be configured as follows. 
     (1) A display unit including 
     a display panel including a display region and a terminal region on a first substrate, the display region including a plurality of pixels, each of the plurality of pixels including a light emitting element, and the terminal region including a plurality of terminals at a part of a peripheral region of the display region, wherein 
     the light emitting element includes a first electrode, an organic layer, and a second electrode that is provided commonly to the plurality of pixels, in order from the first substrate side, and 
     the second electrode extends, continuously in a plan view, to an end of the first substrate in a region on the first substrate except for the terminal region, and is configured to be electrically disconnected from an exterior member of the display panel. 
     (2) The display unit according to (1), wherein the second electrode is covered with an insulating film provided at the end of the first substrate. 
     (3) The display unit according to (2), wherein 
     the display panel has a rectangular shape in a plan view, 
     the terminal region corresponds to one side of the rectangular shape of the peripheral region on the first substrate, and 
     the insulating film is provided at ends of the first substrate corresponding to three sides except for the one side. 
     (4) The display unit according to any one of (1) to (3), wherein 
     an inverse-tapered structure is provided at a part of the peripheral region in a lower layer of the second electrode, and 
     the second electrode is electrically discontinuous by the structure while being provided continuously in a plan view. 
     (5) The display unit according to (4), wherein 
     the structure is provided in the peripheral region on the first substrate to surround the display region 
     (6) The display unit according to any one of (1) to (5), wherein 
     the display panel includes the first substrate and a second substrate that is provided oppositely to the first substrate and seals the light emitting element, and 
     the second electrode is disposed inside an outermost end of one or both of the first substrate and the second substrate. 
     (7) The display unit according to (6), wherein 
     one or both of the first substrate and the second substrate each have a tapered end surface. 
     (8) The display unit according to any one of (1) to (7), wherein 
     the second electrode is a transparent conductive film. 
     (9) The display unit according to any one of (1) to (8), further including 
     an organic insulating film as an interlayer insulating film or a pixel separation film, wherein 
     the organic insulating film has a separation groove in the peripheral region, and 
     the organic insulating film has an end disposed inside the end of the first substrate. 
     (10) A method of manufacturing a display unit, including: 
     forming a display panel including a display region and a terminal region, the display region including a plurality of pixels, each of the plurality of pixels including a light emitting element, and the terminal region including a plurality of terminals at a part of a peripheral region of the display region; and 
     forming, as the light emitting element, a first electrode, an organic layer, and a second electrode on the first substrate, the second electrode being common to the plurality of pixels, wherein 
     the second electrode is formed to extend, continuously in a plan view, to an end of the first substrate in a region on the first substrate except for the terminal region, and is formed to be electrically disconnected from an exterior member of the display panel. 
     (11) The method according to (10), wherein 
     the second electrode is formed on the first substrate with use of a film formation mask including an opening, and 
     the opening is provided over an entire region on the first substrate except for the terminal region. 
     (12) The method according to (10) or (11), wherein 
     a plurality of the display regions are formed along one direction on the first substrate with use of a film formation mask including one opening for the plurality of display regions. 
     (13) The method according to any one of (10) to (12), wherein 
     the second electrode is covered with an insulating film provided at the end of the first substrate. 
     (14) The method according to any one of (10) to (13), further including 
     forming an inverse-tapered structure at a part of the peripheral region before forming the second electrode, wherein 
     the second electrode is electrically discontinuous while being continuous in a plan view by forming the second electrode on the first substrate with the structure in between. 
     (15) The method according to any one of (10) to (14), wherein 
     the display panel includes the first substrate and a second substrate that is provided oppositely to the first substrate and seals the light emitting element, and 
     the second electrode is disposed inside an outermost end of one or both of the first substrate and the second substrate. 
     (16) The method according to (15), wherein 
     one or both of the first substrate and the second substrate each have a tapered end surface. 
     (17) The method according to any one of (10) to (16), wherein 
     the second electrode is a transparent conductive film. 
     (18) The method according to any one of (10) to (17), further including 
     forming an organic insulating film as an interlayer insulating film or a pixel separation film, the organic insulating film including a separation groove in the peripheral region, and the organic insulating film including an end located inside the end of the first substrate. 
     (19) An electronic apparatus provided with a display unit, the display unit including 
     a display panel including a display region and a terminal region on a first substrate, the display region including a plurality of pixels, each of the plurality of pixels including a light emitting element, and the terminal region being provided at a part of a peripheral region of the display region and including a plurality of terminals, wherein 
     the light emitting element includes a first electrode, an organic layer, and a second electrode in order from the first substrate side, the second electrode being provided commonly to the plurality of pixels, and 
     the second electrode extends, continuously in a plan view, to an end of the first substrate in a region on the first substrate except for the terminal region, and is configured to be electrically disconnected from an exterior member of the display panel. 
     It should be understood by those skilled in the art that various modifications, combinations, sub-combinations, and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.