Patent Publication Number: US-2023146475-A1

Title: Display device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is a Continuation of U.S. application Ser. No. 17/178,751 filed Feb. 18, 2021, which is a Continuation of U.S. application Ser. No. 16/925,844 filed Jul. 10, 2020 (now U.S. Pat No. 10,991,912, issued Apr. 27, 2021), which is a Continuation of U.S. application Ser. No. 16/166,845 filed Oct. 22, 2018 (now U.S. Pat. No. 10,756,299, issued Aug. 25, 2020), which is a Continuation of U.S. application Ser. No. 15/863,204 filed Jan. 5, 2018 (now U.S. Pat No. 10,141,542, issued Nov. 27, 2018), which is a Continuation of U.S. application Ser. No. 15/343,922 filed Nov. 4, 2016 (now U.S. Pat. No. 9,893,316, issued Feb. 13, 2018), and claims priority from Japanese application JP 2016-001317 filed on Jan. 6, 2016, the content of each of which is hereby incorporated by reference into this application. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a display device and a method of manufacturing the display device. 
     2. Description of the Related Art 
     In Japanese Patent Application Laid-open No. 2005-158292, it is disclosed that a pixel electrode is arranged on a planarization insulating film containing an organic material, that an aperture portion is formed in an element isolation film, which covers the planarization insulating film and the pixel electrode, to expose the pixel electrode, and that the element isolation film may contain an organic material. 
     SUMMARY OF THE INVENTION 
     Meanwhile, in a display device including an organic insulating film, as disclosed in Japanese Patent Application Laid-open No. 2004-335267, there are cases where a separation groove, which is configured to block moisture intrusion, is formed between a display region and an edge. 
     When such separation groove is to be applied to the display device including the two-layer organic insulating film as in Japanese Patent Application Laid-open No. 2005-158292, there can be conceived a method in which a first separation groove is formed in the lower organic insulating film, then the upper organic insulating film is formed, and a second separation groove is formed in a portion to fill the first separation groove. However, when the upper organic insulating film is formed by application, the portion to fill the first separation groove becomes thicker than a portion above the lower organic insulating film. Therefore, under etching conditions optimized to form the aperture to expose the pixel electrode, the portion to fill the first separation groove cannot be fully separated by the second separation groove. As a result, a remaining film of the upper organic insulating film serves as a moisture intrusion path, and there is a risk that a sufficient moisture blocking property cannot be obtained. Moreover, under etching conditions optimized so that no remaining film of the upper organic insulating film is generated, the lower organic insulating film is excessively etched, and there is a risk that a pattern defect may be generated. 
     The present invention has been made in view of the above-mentioned problems, and therefore has an object to provide a display device, which is capable of preventing degradation of elements in a light emitting layer due to moisture intrusion to a display portion by improving a moisture blocking property, and a method of manufacturing the display device. 
     A display device, which includes a display region in which a plurality of pixels are arranged, includes a first organic insulating film, a first groove, which exists in a frame shape surrounding the display region to separate the first organic insulating film, a first inorganic partition portion, which is arranged in the first groove, and is made of an inorganic insulating material that exists in a frame shape surrounding the display region, a second organic insulating film formed above the first organic insulating film and the first inorganic partition portion, and a second groove, which exists in a frame shape surrounding the display region to separate the second organic insulating film, and is located inside the first groove in plan view. 
     A method of manufacturing a display device, which includes a display region in which a plurality of pixels are arranged, the method includes forming a first inorganic partition portion, which is made of an inorganic insulating material that exists in a frame shape surrounding the display region, forming a first organic insulating film having a first groove, in which the first inorganic partition portion is arranged, forming a second organic insulating film above the first organic insulating film in a state in which the first inorganic partition portion is arranged in the first groove, and forming a second groove, which exists in a frame shape surrounding the display region to separate the second organic insulating film, and is located inside the first groove in plan view. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a plan view of a display device according to a first embodiment of the present invention. 
         FIG.  2    is a sectional view of the above-mentioned display device. 
         FIG.  3    is views for illustrating manufacturing steps of the above-mentioned display device. 
         FIG.  4    is views for illustrating manufacturing steps of a display device according to a reference example. 
         FIG.  5    is a sectional view of a display device according to a second embodiment of the present invention. 
         FIG.  6    is a sectional view of a display device according to a third embodiment of the present invention. 
         FIG.  7    is a sectional view of a display device according to a fourth embodiment of the present invention. 
         FIG.  8    is a sectional view of a display device according to a fifth embodiment of the present invention. 
         FIG.  9    is a sectional view of a display device according to a sixth embodiment of the present invention. 
         FIG.  10    is a sectional view of a display device according to a seventh embodiment of the present invention. 
         FIG.  11    is a sectional view of a display device according to a modified example of the present invention. 
         FIG.  12    is a sectional view of a display device according to a modified example of the present invention. 
         FIG.  13    is a sectional view of a display device according to a modified example of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Now, embodiments of the present invention are described with reference to the drawings. The disclosure in this specification is merely an example of the present invention, and appropriate changes that can be easily conceived by those skilled in the art without departing from the main gist of the invention are encompassed by the scope of the invention. Moreover, widths, thicknesses, shapes, and the like of the respective parts illustrated in the figures may be schematically illustrated in some cases, and are not to limit the interpretation of the invention. Moreover, in the specification and the figures, elements like those described above with reference to figures that have been already described are denoted by like reference symbols, and detailed description thereof may be omitted as appropriate. 
     As an example of a display device, an organic electro luminescence (EL) display device using organic light-emitting diodes (OLEDs), which are a type of self-light-emitting elements, is described below. 
     First Embodiment 
       FIG.  1    is a plan view of a display device  1  according to a first embodiment of the present invention.  FIG.  2    is a sectional view taken along the line II-II of  FIG.  1   . The display device  1  includes a display panel  2 , and a flexible printed circuit (FPC)  3  mounted to an end portion of the display panel  2 . In a center portion of the display panel  2 , a rectangular display region  2 A, in which a plurality of pixels are arranged in matrix, is provided. It is preferred that the plurality of pixels are classified into a plurality of colors of emitted light, and examples of the colors of emitted light of the pixels include three colors: red, green, and blue, or four colors: red, green, blue, and white. Cyan, magenta, and yellow may be included as the colors of emitted light of the pixels. 
     A frame region  2 C having a frame shape is provided to surround the display region  2 A. In the frame region  2 C, a plurality of moisture blocking structures  4  and  5  are provided to suppress moisture intrusion from an edge  2 E of the display panel  2  to the display region  2 A. The moisture blocking structures  4  and  5  are located between the edge  2 E of the display panel  2  and the display region  2 A, and are formed into frame shapes to surround the display region  2 A. In the example illustrated in the figures, two moisture blocking structures  4  and  5  are arranged in a direction from the edge  2 E to the display region  2 A (this direction is hereinafter referred to as “direction of moisture intrusion”). However, the present invention is not limited thereto, and may include only one moisture blocking structure. Moreover, in the example illustrated in the figures, each of the moisture blocking structures  4  and  5  surrounds the display region  2 A without any interruption. However, the present invention is not limited thereto, and when another inorganic insulating material and other such structures exist inside the frame, the moisture blocking structure may be interrupted in the midway. 
     The display panel  2  includes an array substrate  6 , and an opposing substrate  7 , which is opposed to the array substrate  6 . As illustrated in  FIG.  12   , the opposing substrate  7  may not be provided. The array substrate  6  and the opposing substrate  7  are bonded to each other via a filler  8 . Specifically, a frame-shaped sealing member  9  is provided along the edge  2 E of the display panel  2 , and the filler  8  is filled in a space inside the sealing member  9 . The display panel  2  is, for example, of a top emission type in which light is emitted in a direction of the opposing substrate  7  (this direction is hereinafter referred to as “above”, and a direction opposite to the direction is hereinafter referred to as “below”) with reference to the array substrate  6 . 
     The opposing substrate  7  includes a substrate  61  made of glass, for example. The substrate  61  may be made of a flexible resin, e.g., polyimide, instead. When the display panel  2  is of the top emission type, the substrate  61  is transparent. On the side of the substrate  61  that faces the array substrate  6 , there are provided a black matrix (BM)  63  in which apertures are formed to correspond to light emitting regions of the respective pixels, a color filter  67  formed to partially overlap the BM  63 , and a planarization layer  65  covering the BM  63  and the color filter  67 . The color filter  67  may be provided in the array substrate  6  instead. The planarization layer  65  may not be provided. 
     The array substrate  6  includes a substrate  11  made of glass, for example. The substrate  11  may be made of a flexible resin, e.g., polyimide, instead. When the display panel  2  is of the top emission type, the substrate  11  does not need to be transparent. On a side of the substrate  11  that faces the opposing substrate  7 , pixel circuits  30  corresponding to the respective pixels and the like are provided in the display region  2 A, and the moisture blocking structures  4  and  5  and the like are provided in the frame region  2 C. The pixel circuits  30  include thin film transistors (TFTs), and are arranged to correspond to the respective pixels. 
     In the display region  2 A, a semiconductor film  32  is provided above the substrate  11 . The substrate  11  and the semiconductor film  32  are covered by an interlayer insulating film  13 , and gate electrodes  33  are arranged above the interlayer insulating film  13 . The interlayer insulating film  13  and the gate electrodes  33  are covered by an interlayer insulating film  15 , and source electrodes  34  and drain electrodes  36  are arranged above the interlayer insulating film  15 . Interlayer connection holes for connecting the source electrodes  34  and the drain electrodes  36  to the semiconductor film  32  are formed in the interlayer insulating films  13  and  15 . The semiconductor film  32 , gate electrode  33 , source electrode  34 , and drain electrode  36  form a TFT of the pixel circuit  30 . The gate electrode  33  is connected to a drain electrode of another TFT (not shown), and a power line (not shown) is connected to the source electrode  34 . The semiconductor film  32  includes, for example, an LTPS semiconductor, an amorphous semiconductor, and an oxide semiconductor. The interlayer insulating films  13  and  15  are inorganic insulating films each made of an inorganic material, e.g., silicon oxide or silicon nitride. The gate electrode  33 , the source electrode  34 , and the drain electrode  36  are each made of a metal, e.g., aluminum, silver, copper, nickel, or titanium. 
     In the example illustrated in the figure, the semiconductor film  32  is in contact with the substrate  11 . However, the present invention is not limited thereto, and one or a plurality of undercoat layers  12  as illustrated in  FIG.  11    may be interposed between the substrate  11  and the semiconductor film  32 . The undercoat layers  12  are inorganic insulating films each made of an inorganic material, e.g., silicon oxide or silicon nitride. 
     The interlayer insulating film  15 , the source electrodes  34 , and the drain electrodes  36  are covered by an organic planarization film  17 , and pixel electrodes  38  are arranged above the organic planarization film  17 . Interlayer connection holes are formed in the organic planarization film  17  to connect the pixel electrodes  38  to the drain electrodes  36 . The organic planarization film  17  is an example of a first organic insulating film, and is an organic insulating film containing an organic material, e.g., an acrylic resin. The organic planarization film  17  is formed to be thicker than the other interlayer insulating films, and has a planar upper surface. The pixel electrodes  38  are anodes, for example, and are arranged to correspond to the respective pixels. The pixel electrodes  38  are each made of a metal, e.g., indium tin oxide (ITO), aluminum, silver, copper, nickel, or titanium, and may include a reflection surface. 
     The organic planarization film  17  and the pixel electrodes  38  are covered by a pixel isolation film  19 , and apertures  19 a are formed in the pixel isolation film  19  to expose the pixel electrodes  38  excluding ends thereof. Specifically, the pixel isolation film  19  covers the ends of the pixel electrodes  38 , and the pixel electrodes  38  are exposed in the other regions. Inner edge portions forming the apertures  19   a  of the pixel isolation film  19  have a mildly tapered shape. The pixel isolation film  19  is an example of a second organic insulating film, and is an organic insulating film containing an organic material, e.g., an acrylic resin. The pixel isolation film  19  is also called as banks or ribs. 
     The pixel isolation film  19  and the pixel electrodes  38  exposed in the apertures  19   a  are covered by an organic film  21  containing a light emitting layer. The organic film  21  includes, in order from the pixel electrode  38  side, a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer, for example. The laminate structure of the organic film  21  is not limited thereto, and is not particularly limited as long as at least the light emitting layer is included. In this embodiment, a color of emitted light of the light emitting layer included in the organic film  21  is white. However, the present invention is not limited thereto, and the color may be another color. The organic film  21  is formed by vapor deposition using no mask, for example, and is formed in a range including the display region  2 A to the front of the moisture blocking structure  4  on the inside. 
     The organic film  21  is covered by a counter electrode  23 . The counter electrode  23  is a cathode, for example, and is formed to cover the entire organic film  21 . The counter electrode  23  is made of a transparent conductive material, e.g., indium tin oxide (ITO) or indium zinc oxide (IZO). The counter electrode  23  is formed in a range that covers the organic film  21 , for example, to between the moisture blocking structure  4  on the inside and the moisture blocking structure  5  on the outside. 
     Further, the counter electrode  23  is covered by a sealing film  25 . The sealing film  25  is an inorganic insulating film made of an inorganic material, e.g., silicon oxide or silicon nitride, and is formed over the entire array substrate  6 . The sealing film  25  is in contact with the filler  8  and the sealing member  9 . 
     In the frame region  2 C, the moisture blocking structures  4  and  5 , which separate each of the organic planarization film  17  and the pixel isolation film  19 , are provided. First separation grooves  17   c , which separate the organic planarization film  17 , are formed in the moisture blocking structures  4  and  5 , and an inorganic partition portion  50  is arranged in the first separation groove  17   c . The first separation grooves  17   c  and the inorganic partition portion  50  separate the organic planarization film  17 . The inorganic partition portion  50  is made of an inorganic insulating material, e.g., silicon oxide or silicon nitride. The inorganic insulating material does not allow moisture to pass therethrough, and is not eroded as opposed to a metal. Therefore, the inorganic insulating material is optimal as a structure for blocking moisture. The inorganic partition portion  50  has, for example, a trapezoid sectional shape, which has an upper surface and is increased in width toward the bottom. To the contrary, the first separation groove  17   c  has an overhang shape in which a width on the upper side is smaller than a width on the lower side. The upper surface of the inorganic partition portion  50  is located above an upper surface of the organic planarization film  17 , and is at about the same height as upper surfaces of the pixel electrodes  38 , for example. 
     Second separation grooves  19   c  are also formed in the moisture blocking structures  4  and  5  to separate the pixel isolation film  19 . The second separation groove  19   c  is formed to be contained inside the first separation groove  17   c  in plan view. For example, a lower aperture of the second separation groove  19   c  may be contained inside an upper aperture of the first separation groove  17   c  in plan view. The second separation groove  19   c  does not always need be formed to be contained inside the first separation groove  17   c  as long as the second separation groove  19   c  overlaps the first separation groove  17   c  in plan view. The second separation groove  19   c  has its bottom at the upper surface of the inorganic partition portion  50 , and is formed so that a lower aperture of the second separation groove  19   c  is contained in the upper surface of the inorganic partition portion  50 , for example. An edge portion that forms the second separation groove  19   c  of the pixel isolation film  19  is in contact with an upper corner portion of the inorganic partition portion  50 . 
     The counter electrode  23  and the sealing film  25  are further laminated above the inorganic partition portion  50  of the moisture blocking structure  4  on the inside, and the sealing film  25  is further laminated above the inorganic partition portion  50  of the moisture blocking structure  5  on the outside. 
     A conductive film  39  in the same layer as the pixel electrodes  38  is formed between the moisture blocking structure  4  on the inside and the moisture blocking structure  5  on the outside, and the counter electrode  23  is connected to the conductive film  39  via apertures formed in the pixel isolation film  19 . In this embodiment, an organic layer exists between the moisture blocking structure  5  and the edge  2 E, but a structure without the organic layer may be adopted as in  FIG.  13   . 
     As described above, the first separation grooves  17   c , the second separation grooves  19   c , and the inorganic partition portion  50  form the moisture blocking structures  4  and  5 . With this structure, the organic planarization film  17  and the pixel isolation film  19  are separated by the moisture blocking structures  4  and  5 , and no film containing an organic material extends across the region of the moisture blocking structures  4  and  5 . In other words, none of the films that extend across the region of the moisture blocking structures  4  and  5  contain an organic material. Therefore, moisture intrusion from the edge  2 E of the display panel  2  to the display region  2 A may be suppressed, and the moisture blocking property may be improved. 
     In the frame region  2 C, circuit elements  40  containing TFTs, which are similar to the pixel circuits  30 , are arranged below the inorganic partition portion  50 . The circuit element  40  is a gate drive circuit, for example. The circuit element  40  includes a conductive film  36   c  in the same layer as the source electrodes  34  and the drain electrodes  36  of the pixel circuits  30 . Moreover, wiring  47  that extends across the region of the moisture blocking structures  4  and  5  is arranged between the inorganic partition portion  50  and the interlayer insulating film  15 . The wiring  47  is connected to the circuit elements  40 . The wiring  47  is made of the conductive film  36   c  in the same layer as the source electrodes  34  and the drain electrodes  36  of the pixel circuits  30 . The drain electrode  36  is an example of a lower electrode. The “same layer” as used herein refers to a layer formed at the same time and made of the same material. 
     In this embodiment, the inorganic partition portion  50  is provided in the moisture blocking structures  4  and  5 , and the counter electrode  23  is arranged above the inorganic partition portion  50 . Therefore, the conductive film  36   c  in the same layer as the source electrodes  34  and the drain electrodes  36  of the pixel circuits  30  may be arranged in the region of the moisture blocking structures  4  and  5  without any need to consider a short circuit with the counter electrode  23 . With this structure, the circuit elements  40  and the wiring  47  using the conductive film  36  may be provided in the region of the moisture blocking structures  4  and  5 . Moreover, the circuit elements  40  may be arranged in the region of the moisture blocking structures  4  and  5 , and hence a contribution may be made toward narrowing the frame. 
     [Manufacturing Method] 
       FIG.  3    is views for illustrating a part of manufacturing steps of the display device  1 . In the figure, the insulating film below the interlayer insulating film  15  and a part of the conductive films are omitted. 
     In a step (a), the inorganic partition portion  50  is selectively formed above the interlayer insulating film  15 . The selective formation of the inorganic partition portion  50  is realized by, for example, forming a coating film made of an inorganic material to cover the interlayer insulating film  15  by chemical vapor deposition (CVD), and patterning the coating film by a photoetching technology. The inorganic partition portion  50  is made of an inorganic material, e.g., silicon oxide or silicon nitride. The inorganic partition portion  50  has a thickness of about 2.2 μm, for example. 
     In a step (b), a coating film  17   p , which is to form the organic planarization film  17  later, is formed above the interlayer insulating film  15 . The formation of the coating film  17   p  is realized by a coating method, e.g., spin coating, and an upper surface of the coating film  17   p  is formed to be flat. Here, the coating film  17   p  is formed by the coating method under the state in which the inorganic partition portion  50  is formed, and hence the coating film  17   p  is formed to avoid the inorganic partition portion  50  so that an upper portion of the inorganic partition portion  50  projects from the upper surface of the coating film  17   p . As a result, the first separation grooves  17   c , which separate the coating film  17   p  in an in-plane direction, and are filled with the inorganic partition portion  50 , are formed. In other words, an interface between the coating film  17   p  and the inorganic partition portion  50  forms the first separation groove  17   c . The coating film  17   p  contains an organic material, e.g., an acrylic resin. The coating film  17   p  has a thickness of about 2 μm, for example. 
     The present invention is not limited to the above-mentioned method. For example, the first separation grooves  17   c  are formed in the coating film  17   p , and then the inorganic partition portion  50  may be formed inside the first separation grooves  17   c.    
     In a step (c), the coating film  17   p  is patterned by a photoetching technology to complete the organic planarization film  17 . The organic planarization film  17  having a flat upper surface is formed to suppress the short circuit of the pixel electrode  38  and the counter electrode  23  due to a disconnection in the organic film  21  including the light emitting layer, and to prevent the disconnection of the organic film (see  FIG.  2   ). 
     In a step (d), the pixel electrodes  38  and the conductive film  39  are selectively formed above the organic planarization film  17 . The selective formation of the pixel electrodes  38  and the conductive film  39  is realized by, for example, forming a metal film to cover the organic planarization film  17  by sputtering or vapor deposition, and patterning the metal film by a photoetching technology. The pixel electrodes  38  and the conductive film  39  are made of metals, e.g., indium tin oxide (ITO), aluminum, silver, copper, nickel, and titanium. The pixel electrodes  38  and the conductive film  39  have a thickness of about 0.2 μm, for example. 
     In a step (e), a coating film  19   p , which is to form the pixel isolation film  19  later, is formed above the organic planarization film  17 , the inorganic partition portion  50 , the pixel electrodes  38 , and the conductive film  39 . The formation of the coating film  19   p  is realized by a coating method, e.g., spin coating, and an upper surface of the coating film  19   p  is formed to be flat. The coating film  19   p  contains an organic material, e.g., an acrylic resin. The coating film  19   p  has a thickness of about 1 μm, for example. 
     In a step (f), the apertures  19   a , which expose the pixel electrodes  38 , and the second separation grooves  19   c , which separate the coating film  19   p , are formed in the coating film  19   p  at the same time to complete the pixel isolation film  19 . 
     In this embodiment, the inorganic partition portion  50  is arranged in the first separation grooves  17   c , and hence a portion of the coating film  19   p  that is formed above the inorganic partition portion  50  becomes thinner than in a case where the inorganic partition portion  50  is not arranged (see  FIG.  4   , which is to be described later). Therefore, even under etching conditions optimized to form the apertures  19   a  in the coating film  19   p , reliability of removing the portion of the coating film  19   p  that is formed above the inorganic partition portion  50  may be improved, and the second separation grooves  19   c  with, if any, a very small residue. As a result, the moisture blocking property is improved. 
     It is preferred that the upper surface of the inorganic partition portion  50  is located above the upper surface of the organic planarization film  17  and below the upper surface of the pixel isolation film  19 , and it is particularly preferred that the upper surface of the inorganic partition portion  50  is located at about the same height as the upper surface of the pixel electrodes  38 . In this case, the portion of the coating film  19   p  that is formed above the inorganic partition portion  50  has about the same thickness as portions of the coating film  19   p  that are formed above the pixel electrodes  38 . Therefore, the etching conditions optimized to form the apertures  19   a  in the coating film  19   p  are also optimized to form the second separation grooves  19   c , and the reliability of removal is further improved. 
     REFERENCE EXAMPLE 
       FIG.  4    is views for illustrating manufacturing steps of a display device according to a reference example in which the above-mentioned inorganic partition portion  50  is not provided. In a step (x), first separation grooves  97   c  are formed in an organic planarization film  97 , and pixel electrodes  98  are selectively formed above the organic planarization film  97 . At the bottom of the first separation grooves  97   c , an interlayer insulating film  95  is exposed. 
     In a step (y), a coating film  99   p , which is to form a pixel isolation film  99  later, is formed above the organic planarization film  97  and the interlayer insulating film  95 , which is exposed at the bottom of the first separation grooves  97   c , by a coating method, e.g., spin coating. At this time, inside the first separation grooves  97   c , a filling portion  99   y , in which a material of the coating film  99   p  is filled in a large amount, is formed. The filling portion  99   y  becomes thicker than the portion of the coating film  99   p  that is formed above the pixel electrodes  98 . 
     In a step (z), the coating film  99   p  is patterned by a photoetching technology to form apertures  99   a , which expose the pixel electrodes  98 , and second separation grooves  99   c , which separate the coating film  99   p . However, with the thick filling portion  99   y  existing inside the first separation grooves  97   c , under etching conditions optimized to form the apertures  99   a  in the coating film  99   p , there is a risk that the filling portion  99   y  cannot be removed completely to form a residue  99   z , resulting in an insufficient moisture blocking property. 
     Second Embodiment 
       FIG.  5    is a sectional view of a display device according to a second embodiment of the present invention. In the moisture blocking structures  4  and  5  in the second embodiment, the upper surface of the inorganic partition portion  50  is located below the upper surface of the organic planarization film  17 , and the second separation grooves  19   c  are located inside the first separation grooves  17   c . The first separation grooves  17   c  are formed by, for example, first forming the inorganic partition portion  50 , forming in this state a coating film, which covers the inorganic partition portion  50  and is to form the organic planarization film  17 , and etching to remove a portion of the coating film that is formed above the inorganic partition portion  50 . Therefore, the first separation groove  17   c  includes a lower portion in which the inorganic partition portion  50  is provided, and an upper portion formed by etching. The second separation groove  19   c  has its bottom at the upper surface of the inorganic partition portion  50 , and an edge portion of the pixel isolation film  19  that forms the second separation groove  19   c  covers an inclined surface of the first separation groove  17   c , and is in contact with the upper surface of the inorganic partition portion  50 . The organic planarization film  17  has a thickness of about 2 μm, for example, and the inorganic partition portion  50  has a thickness of about 1.5 μm, for example. 
     Even with the upper surface of the inorganic partition portion  50  being located below the upper surface of the organic planarization film  17  as described above, when the pixel isolation film  19  is formed, the portion of the coating film, which is to form the pixel isolation film  19 , that is formed above the inorganic partition portion  50  becomes thinner than when the inorganic partition portion  50  is not provided, and hence the reliability of removing the portion is improved, to thereby improve the moisture blocking property. Moreover, the time required to form the inorganic partition portion  50 , for example, the time required to deposit the coating film, which is to form the inorganic partition portion  50 , may be reduced than in the first embodiment. Therefore, both the moisture blocking property and productivity is achieved. 
     Third Embodiment 
       FIG.  6    is a sectional view of a display device according to a third embodiment of the present invention. In the moisture blocking structures  4  and  5  in the third embodiment, an organic base  52  is provided inside the inorganic partition portion  50 . Specifically, the organic base  52  is provided above the interlayer insulating film  15 , and the inorganic partition portion  50  is formed to cover the organic base  52 . An upper surface and side surfaces of the organic base  52  are covered by the inorganic partition portion  50 , and a lower surface of the organic base  52  is covered by the interlayer insulating film  15  and a conductive layer  36   c . With such inorganic partition portion  50  in which the organic base  52  is provided inside, the moisture blocking structures  4  and  5  may be realized. Moreover, an organic material is easier to quickly form a thick coating film as compared to an inorganic material. Therefore, a reduction in time required for the formation is achieved by providing the organic base  52  in advance and forming the inorganic partition portion  50  to cover the organic base  52 . 
     Fourth Embodiment 
       FIG.  7    is a sectional view of a display device according to a fourth embodiment of the present invention. In the moisture blocking structures  4  and  5  in the fourth embodiment, the conductive film  38   c  in the same layer as the pixel electrodes  38  is provided above the inorganic partition portion  50 . The upper surface of the inorganic partition portion  50  is located below the upper surface of the organic planarization film  17 , and the conductive film  38   c  is located inside the first separation grooves  17   c . The upper surface of the conductive film  38   c  is located below the upper surface of the organic planarization film  17 . However, the present invention is not limited thereto, and the upper surface of the conductive film  38   c  may be located above the upper surface of the organic planarization film  17 . The second separation groove  19   c  has its bottom at the upper surface of the conductive film  38   c , and an edge portion that forms the second separation groove  19   c  of the pixel isolation film  19  covers an inclined surface of the first separation groove  17   c , and is in contact with the upper surface of the conductive film  38   c . The conductive film  38   c  is electrically isolated from the pixel electrode  38 . 
     With the conductive film  38   c  being provided above the inorganic partition portion  50  as described above, a total thickness of the inorganic partition portion  50  and the conductive film  38   c  is enough to improve the moisture blocking property. In other words, in forming the pixel isolation film  19 , a thickness of a portion of the coating film, which is to form the pixel isolation film  19 , that is formed above the conductive film  38   c  becomes thinner than in the second embodiment. Therefore, the reliability of removing the portion may be further improved, and as a result, the moisture blocking property is improved. 
     Fifth Embodiment 
       FIG.  8    is a sectional view of a display device according to a fifth embodiment of the present invention. In the moisture blocking structures  4  and  5  in the fifth embodiment, the inorganic partition portion  50  is formed utilizing the interlayer insulating film  15 . In the example illustrated in the figure, an inorganic base  51  is provided above the substrate  11 , and the interlayer insulating films  13  and  15  are laminated above the inorganic base  51  to form the inorganic partition portion  50  having the upper surface and the side surfaces that are made of the interlayer insulating film  15 . The inorganic base  51  is made of an inorganic material, e.g., silicon oxide or silicon nitride. With such inorganic partition portion  50  formed utilizing the interlayer insulating film  15 , the moisture blocking property is improved. 
     Incidentally, in the fifth embodiment, the upper surface of the interlayer insulating film  15  forming the inorganic partition portion  50  forms the bottom of the second separation grooves  19   c . In this case, when the wiring  47  (see  FIG.  2    etc.) in the same layer as the source electrodes  34  and the drain electrodes  36  of the pixel circuits  30  is formed on an upper surface of the interlayer insulating film  15  forming the inorganic partition portion  50 , a short circuit with the counter electrode  23  becomes a problem. Therefore, in the fifth embodiment, in the region of the moisture blocking structures  4  and  5 , wiring  48  in the same layer as the gate electrodes  33  of the pixel circuits  30  is utilized. Specifically, in regions other than the moisture blocking structures  4  and  5  of the frame region  2 C, wiring  49  in the same layer as the source electrodes  34  and the drain electrodes  36  of the pixel circuits  30  is provided, and in the region of the moisture blocking structures  4  and  5 , the wiring  48  in the same layer as the gate electrodes  33  of the pixel circuits  30 , which is connected to the wiring  49  via interlayer connection holes formed in the interlayer insulating film  15 , is provided between the interlayer insulating films  13  and  15 . 
     Sixth Embodiment 
       FIG.  9    is a sectional view of a display device according to a sixth embodiment of the present invention. In the sixth embodiment, the interlayer insulating film  18  is provided between the organic planarization film  17  and the pixel isolation film  19 , and capacitance forming electrodes  37 , which are opposed to the pixel electrodes  38  with the interlayer insulating film  18  being interposed between the capacitance forming electrodes  37  and the pixel electrodes  38 , are arranged between the organic planarization film  17  and the interlayer insulating film  18 . The interlayer insulating film  18  is an inorganic insulating film made of an inorganic material, e.g., silicon oxide or silicon nitride. The capacitance forming electrodes  37  are each made of a metal, e.g., aluminum, silver, copper, nickel, or titanium. 
     The interlayer insulating film  18  and the capacitance forming electrodes  37  extend also to the frame region  2 C. The interlayer insulating film  18  extends over the entire frame region  2 C, and the capacitance forming electrodes  37  extend past the moisture blocking structure  4  on the inside and to between the moisture blocking structure  4  on the inside and the moisture blocking structure  5  on the outside, for example. As a result, the interlayer insulating film  18  and the capacitance forming electrode  37  are provided above the inorganic partition portion  50  in the moisture blocking structure  4  on the inside, and the interlayer insulating film  18  is provided above the inorganic partition portion  50  in the moisture blocking structure  5  on the outside. The second separation groove  19   c  has its bottom at a portion of the interlayer insulating film  18  that is formed above the inorganic partition portion  50 , for example. Moreover, the capacitance forming electrode  37  is connected to the counter electrode  23  via the conductive film  39  between the moisture blocking structure  4  on the inside and the moisture blocking structure  5  on the outside so that the capacitance forming electrode  37  and the counter electrode  23  have the same potential. Even when at least one of the interlayer insulating film  18  and the capacitance forming electrode  37  is provided above the inorganic partition portion  50  as described above, the moisture blocking property is improved. Further, with the interlayer insulating film  18  and the capacitance forming electrode  37  being provided above the inorganic partition portion  50  as described above, a total thickness of the inorganic partition portion  50 , the interlayer insulating film  18 , and the capacitance forming electrode  37  is enough to improve the moisture blocking property. In other words, in forming the pixel isolation film  19 , a thickness of a portion of the coating film, which is to form the pixel isolation film  19 , that is formed above the interlayer insulating film  18  becomes thinner than in the second embodiment. Therefore, the reliability of removing the portion is further improved, and as a result, the moisture blocking property is improved. 
     Seventh Embodiment 
       FIG.  10    is a sectional view of a display device according to a seventh embodiment of the present invention. In the moisture blocking structures  4  and  5  in the seventh embodiment, the inorganic partition portion  50  includes the inorganic base  51  and the conductive film  36   c , and the capacitance forming electrode  37 , the interlayer insulating film  18 , and the conductive film  38   c  are arranged above the inorganic partition portion  50 . The second separation groove  19   c  has its bottom at the upper surface of the conductive film  38   c . The inorganic base  51 , the conductive film  36   c , the capacitance forming electrode  37 , the interlayer insulating film  18 , and the conductive film  38   c  are utilized as described above to secure a total thickness thereof, and to improve the moisture blocking property. In other words, in forming the pixel isolation film  19 , a thickness of a portion, which is formed above the conductive film  38   c , of the coating film, which is to form the pixel isolation film  19 , becomes thinner than in the second embodiment. Therefore, the reliability of removing the portion is further improved, and as a result, the moisture blocking property may be improved. 
     MODIFIED EXAMPLE 
     The above-mentioned sixth embodiment (see  FIG.  9   ) may be applied to a display device having the sectional structure illustrated in  FIG.  11   . In this modified example, the TFTs of the pixel circuits  30  arranged in the display region  2 A are N-channel (Nch) TFTs, for example, and the circuit elements  40 , e.g., the gate drive circuits, arranged in the frame region  2 C are P-channel (Pch) TFTs, for example. In the Nch TFT, a low-density impurity region is provided between a channel region opposed to the gate electrode  33  of the semiconductor film  32 , and a connection region in which the source electrode  34  and the drain electrode  36  are connected to each other. Also in the Pch TFT, a low-density impurity region is provided between a channel region opposed to the gate electrode  43  of the semiconductor film  42  and the connection region in which the source electrode  44  and the drain electrode  46  are connected to each other. 
     An extending portion of the gate electrode  33  of the pixel circuit  30  forms a storage capacitor line, and forms a storage capacitor with the semiconductor film  32 . Moreover, the extending portion of the gate electrode  33  also forms a storage capacitor with an extending portion of the drain electrode  36 . 
     The conductive layer including the gate electrodes  33  and  43  has the laminate structure in which aluminum and titanium are laminated, for example. The conductive layer including the source electrodes  34  and  44  and the drain electrodes  36  and  46  has the laminate structure in which titanium, aluminum, and titanium are laminated in the stated order, for example. The wiring formed of the conductive layer including the source electrodes  34  and  44  and the drain electrodes  36  and  46  is routed to a terminal portion provided in an end portion of the array substrate  6  to form a terminal  70 . In portions of the conductive layer including the source electrodes  34  and  44  and the drain electrodes  36  and  46  that are exposed by removing the organic planarization film  17  and other such portions, conductive films  381 ,  382 , and  383  are formed made of a transparent conductive material, e.g., ITO. Specifically, the conductive film  381  is formed in an interlayer connection hole formed in the organic planarization film  17  to expose the drain electrode  36  in the display region  2 A. Further, an interlayer connection hole is also formed in the interlayer insulating film  18 , which fills the interlayer connection hole in the organic planarization film  17 , and allows the pixel electrode  38  to be connected to the conductive film  381 . The conductive film  382  is formed on the upper surface of the organic planarization film  17  in the frame region  2 C to connect the capacitance forming electrode  37  and the counter electrode  23  to each other. In other words, the conductive film  382  is connected to the capacitance forming electrode  37 , which is also arranged between the organic planarization film  17  and the pixel isolation film  19 , and is also connected to the counter electrode  23  via the interlayer connection hole formed in the pixel isolation film  19 . The terminal  70  in the terminal portion is covered by the conductive film  383 . 
     The capacitance forming electrode  37  has the laminate structure in which molybdenum, aluminum, and molybdenum are laminated in the stated order, for example. The pixel electrode  38  has the laminate structure in which ITO, silver, and ITO are laminated in the stated order, for example. 
     While there have been described what are at present considered to be certain embodiments of the invention, it will be understood that various modifications may be made thereto, and it is intended that the appended claims cover all such modifications as fall within the true spirit and scope of the invention.