Patent Publication Number: US-2018054861-A1

Title: Planar light-emitting module

Description:
TECHNOLOGICAL FIELD 
     The present invention relates to a planar light-emitting module including a sheet for sealing a planar light-emitting element. 
     BACKGROUND 
     A planar light-emitting element is formed with a thin planar light source such as organic EL. Planar light-emitting modules including planar light-emitting elements are installed both indoors and outdoors and utilized in a wide variety of applications such as signage, signs, backlights, lighting, and illumination. The planar light-emitting elements require protection from dust, ultraviolet rays, and weather. In general, the planar light-emitting element is disposed between a pair of sheets and sealed so as to be sandwiched between the pair of sheets (for example, see PTDs 1, 2 below). 
     In the organic EL device disclosed in PTD 1 (Japanese Laid-Open Patent Publication No. 2010-244698), a pair of sealing sheets are bonded to each other using adhesive with a wiring member disposed between the end portions of the pair of sealing sheets (in other words, with a wiring member interposed between the end portions of the pair of sealing sheets). The end portions of the pair of sealing sheets have steps due to the presence of the wiring member, and the adhesive is affected by the steps and fails to fulfill sufficient adhesion performance. The invention disclosed in PTD 1 prevents reduction in sealing performance by filling the gap formed between the pair of sealing sheets and the organic EL panel and the gap formed between the pair of sealing sheets and the wiring member with sealing resin. 
     In the electroluminescence light disclosed in Japanese Laid-Open Patent Publication No. H01-117295 (PTD 2), a planar light-emitting element and electrode lead terminals are sealed by a pair of films, conductors (electrode pins) are inserted from the outside of one of the films, and the inserted ends of the conductors are connected to the electrode lead terminals. The outer ends of the conductors protrude outward of the film, and the planar light-emitting element is fed through the protruding portions. According to the description in PTD 2, high sealing performance can be achieved because the entire planar light-emitting element and the entire electrode lead terminals can be sealed without exposing the electrode lead terminals on the outside. 
     CITATION LIST 
     Patent Document 
     PTD 1: Japanese Laid-Open Patent Publication No. 2010-244698 
     PTD 2: Japanese Laid-Open Patent Publication No. H01-117295 
     SUMMARY 
     Technical Problem 
     When the configuration disclosed in PTD 1 (Japanese Laid-Open Patent Publication No. 2010-244698) is employed, that is, when the end portions of a pair of sealing sheets are to be bonded with a wiring member interposed between the end portions of the pair of sealing sheets, a gap is easily formed between the end portions of the pair of sealing sheets due to the presence of the wiring member (step) and, therefore, it is not easy to achieve sufficient sealing performance. 
     When the configuration disclosed in Japanese Laid-Open Patent Publication No. H01-117295 (PTD 2) is employed, the insertion of the conductor (electrode pin) causes breakage of part of the sealing sheet. The sealing sheet may be further broken from the broken part, and it is not easy to keep reliable sealing performance for a long time. 
     The present invention is made in view of the foregoing situation and is aimed to provide a planar light-emitting module having a configuration that can suppress reduction of sealing performance due to the presence of a wiring member. 
     Solution to Problem 
     A planar light-emitting module based on an aspect of the present invention includes a first sealing sheet having an opening, a second sealing sheet bonded to the first sealing sheet, a planar light-emitting element disposed between the first sealing sheet and the second sealing sheet and sealed by the first sealing sheet and the second sealing sheet, and a wiring member disposed between the first sealing sheet and the second sealing sheet and electrically connected to the planar light-emitting element. The wiring member includes a substrate, an electrode formed on the substrate and having an exposed portion disposed so as to be exposable from the opening of the first sealing sheet, and a protective film having an aperture corresponding to the exposed portion and provided so as to cover at least periphery of the exposed portion of the electrode. One exposed portion described above is exposable through one opening and one aperture described above. An edge portion that forms the opening in the first sealing sheet is located outside the aperture and located on a portion having a flat shape in a surface of the protective film. 
     A planar light-emitting module based on another aspect of the present invention includes a first sealing sheet having an opening, a second sealing sheet bonded to the first sealing sheet, a planar light-emitting element disposed between the first sealing sheet and the second sealing sheet and sealed by the first sealing sheet and the second sealing sheet, and a wiring member disposed between the first sealing sheet and the second sealing sheet and electrically connected to the planar light-emitting element. The wiring member includes a substrate and an electrode formed on the substrate and having an exposed portion disposed so as to be exposable from the opening of the first sealing sheet. One exposed portion described above is exposable through one opening described above. An edge portion that forms the opening in the first sealing sheet is located on a portion having a flat shape in a surface of the electrode. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view showing a planar light-emitting module in a first embodiment. 
         FIG. 2  is a plan view showing the planar light-emitting module in the first embodiment in an exploded state. 
         FIG. 3  is a plan view showing the planar light-emitting module in the first embodiment in a further exploded state. 
         FIG. 4  is a cross-sectional view taken along the line IV-IV in  FIG. 3 . 
         FIG. 5  is a plan view for explaining the operation and effects of the planar light-emitting module in the first embodiment. 
         FIG. 6  is a plan view showing a planar light-emitting module in a comparative example. 
         FIG. 7  is a plan view showing the planar light-emitting module in the comparative example in an exploded state. 
         FIG. 8  is a plan view for explaining the operation and effects of the planar light-emitting module in the comparative example. 
         FIG. 9  is a plan view showing a planar light-emitting module in a second embodiment. 
         FIG. 10  is a plan view showing the planar light-emitting module in the second embodiment in an exploded state. 
         FIG. 11  is a plan view for explaining the operation and effects of the planar light-emitting module in the second embodiment. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Embodiments will be described below with reference to the drawings. The same parts and corresponding parts are denoted with the same reference numerals and an overlapping description may not be repeated. 
     First Embodiment 
     (Planar Light-Emitting Module  100 ) 
     Referring to  FIG. 1  to  FIG. 5 , a planar light-emitting module  100  in a first embodiment will be described.  FIG. 1  is a plan view showing planar light-emitting module  100 ,  FIG. 2  is a plan view showing planar light-emitting module  100  in an exploded state,  FIG. 3  is a plan view showing planar light-emitting module  100  in a further exploded state, and  FIG. 4  is a cross-sectional view taken along the line IV-IV in  FIG. 3 .  FIG. 5  is a plan view for explaining the operation and effects of planar light-emitting module  100 . 
     Planar light-emitting module  100  is connected with, for example, external wiring  40  (see  FIG. 1 ), and planar light-emitting module  100  can be used in various applications such as lighting, decoration, and backlights. External wiring  40  is formed of, for example, FPC and includes contact portions  41 ,  42  and a substrate  43  for holding them. As will be detailed later, contact portions  41 ,  42  are connected to feeding portions  32 R,  33 L (exposed portion), respectively, of planar light-emitting module  100  through not-shown conductive adhesive (ACF). 
     Planar light-emitting module  100  is configured such that a planar light-emitting element  10  is sandwiched between and sealed by a pair of sealing sheets  21 ,  22  ( FIG. 1 ,  FIG. 2 ) from above and below. For the sake of convenience,  FIG. 2  shows planar light-emitting element  10  using a dashed and double-dotted line, and  FIG. 3  does not show sealing sheet  21 . More specifically, planar light-emitting module  100  includes planar light-emitting element  10 , a pair of sealing sheet  21  (first sealing sheet) and sealing sheet  22  (second sealing sheet) holding planar light-emitting element  10  from above and below, and a wiring member  30  electrically connected to planar light-emitting element  10  for feeding planar light-emitting element  10 . They will be described one by one below. 
     (Planar Light-Emitting Element  10 ) 
     As shown in  FIG. 1  to  FIG. 4  (mainly  FIG. 3  and  FIG. 4 ), planar light-emitting element  10  is formed of organic EL and disposed between sealing sheet  21  and sealing sheet  22 . Planar light-emitting element  10  is disposed such that a front surface  10 S (light-emitting surface) is positioned on the side on which sealing sheet  21  is disposed (the front side of the drawing sheet of  FIG. 2 ). The thickness of planar light-emitting element  10  is, for example, 50 μm to 200 μm. It is preferable that planar light-emitting element  10  has flexibility. Planar light-emitting element  10  in the present embodiment has a rectangular shape in a two-dimensional view (see  FIG. 3 ). 
     As shown in  FIG. 4 , planar light-emitting element  10  includes a transparent substrate  11 , a barrier layer  12 , an anode  13 , an emissive layer  14 , a cathode  15 , a sealing member  16 , and an insulating layer  17 . Transparent substrate  11 , barrier layer  12 , anode  13 , emissive layer  14 , cathode  15 , and sealing member  16  are stacked in order from the front surface  10 S (light-emitting surface) side of planar light-emitting element  10  toward the back surface side of planar light-emitting element  10 . 
     Transparent substrate  11  is formed of glass, thin film glass, resin film, or the like. Transparent substrate  11  is a member that forms front surface  10 S of planar light-emitting element  10  and has a rectangular shape in a two-dimensional view. Barrier layer  12  has transparency and is formed to cover the whole of the surface of transparent substrate  11 . Barrier layer  12  is formed of, for example, a silicon compound such as silicon oxide and silicon nitride or a metal compound such as metal oxide and metal nitride, or a mixture thereof. 
     Anode  13  is a conductive film having transparency and is formed by depositing ITO or the like on barrier layer  12 . An ITO film for forming anode  13  is divided into two regions by patterning to form a feeding portion  18  (for anode) and a feeding portion  19  (for cathode). The ITO film that forms feeding portion  19  is connected to cathode  15 . 
     When supplied power, emissive layer  14  produces light by the action of field effect. Emissive layer  14  is formed with a single layer or a plurality of stacked layers. Cathode  15  is, for example, aluminum (Al) and is formed to cover emissive layer  14 . Insulating layer  17  is provided between cathode  15  and anode  13 . A portion of cathode  15  that is opposite to the side on which insulating layer  17  ( FIG. 3 ) is located is connected to the ITO film that forms feeding portion  19 . 
     Sealing member  16  is formed of glass, thin film glass, resin film, or the like. Sealing member  16  seals almost the whole of anode  13 , emissive layer  14 , and cathode  15  on transparent substrate  11  (on barrier layer  12 ). Part of the ITO film formed on barrier layer  12  is exposed from sealing member  16  to form feeding portions  18 ,  19  (portions where electrical connection is made). Feeding portions  18 ,  19  are located on the outside of sealing member  16  and located opposite to each other with respect to sealing member  16  (emissive layer  14 ). 
     In planar light-emitting element  10  configured as described above, power is fed through wiring member  30  (which will be detailed later), feeding portions  18 ,  19 , anode  13 , and cathode  15  to emissive layer  14 . Light is produced in emissive layer  14 , and the light passes through anode  13 , barrier layer  12 , and transparent substrate  11  and is extracted from front surface  10 S of planar light-emitting element  10 . 
     (Sealing Sheets  21 ,  22 ) 
     Referring to  FIG. 1  to  FIG. 3 , a pair of sealing sheet  21  and sealing sheet  22  are bonded to each other to seal planar light-emitting element  10  in the inside thereof. For example, a resin member having a sheet shape or a film shape is used as sealing sheets  21 ,  22 . It is preferable that sealing sheets  21 ,  22  have flexibility. The thickness of sealing sheets  21 ,  22  is, for example, 25 μm to 50 μm. 
     Examples of the specific material of sealing sheets  21 ,  22  include polyethylene terephthalate, polypropylene, acrylic, polyimide, and polysulfone. In addition to these materials, a variety of films deposited for improving the barrier characteristic may be used for sealing sheets  21 ,  22 . The color of sealing sheets  21 ,  22  is not limited, and at least sealing sheet  21  of sealing sheets  21 ,  22  has high transparency to allow light emitted from front surface  10 S of planar light-emitting element  10  to pass through. Sealing sheet  22  may also have transparency. 
     Adhesive (not shown) is provided on the inside surfaces of sealing sheets  21 ,  22  to bond sealing sheets  21 ,  22 . For example, a variety of materials such as thermoplastic resin, thermosetting resin, and UV curable resin can be used as adhesive. The thickness of adhesive is, for example, 20 μm to 50 μm. 
     As shown in  FIG. 2 , sealing sheets  21 ,  22  have a rectangular portion larger than the area of planar light-emitting element  10 . Wiring member  30  described later (substrate  31 , electrodes  32 ,  33 , and protective film  34 ) is disposed on the rectangular portion of sealing sheet  22 . Planar light-emitting element  10  is placed on wiring member  30  (protective film  34 ) such that sealing member  16  of planar light-emitting element  10  (see  FIG. 4 ) overlaps protective film  34  of wiring member  30 . Wiring member  30  includes electrodes  32 ,  33 , and electrodes  32 ,  33  (linear portions  32   a ,  33   a ) are electrically connected to feeding portions  19 ,  18  of planar light-emitting element  10 , respectively. 
     As shown in  FIG. 1  and  FIG. 2 , sealing sheet  21  has a pair of openings  21 L,  21 R ( FIG. 2 ). The position of opening  21 L corresponds to the position of feeding portion  33 L of wiring member  30  and the position of aperture  34 L provided in protective film  34  of wiring member  30  (see  FIG. 1 ). Specifically, when planar light-emitting element  10  and wiring member  30  are sandwiched and sealed between a pair of sealing sheets  21 ,  22  from above and below, feeding portion  33 L is located on the inside of aperture  34 L, and feeding portion  33 L and aperture  34 L are located on the inside of opening  21 L when feeding portion  33 L, aperture  34 L, and opening  21 L are viewed from the direction parallel to the direction in which planar light-emitting element  10 , wiring member  30 , and sealing sheets  21 ,  22  are superimposed on each other (when viewed two-dimensionally). 
     The position of opening  21 R corresponds to the position of feeding portion  32 R of wiring member  30  and the position of aperture  34 R provided in protective film  34  of wiring member  30 . Specifically, when planar light-emitting element  10  and wiring member  30  are sandwiched and sealed between a pair of sealing sheets  21 ,  22  from above and below, feeding portion  32 R is located on the inside of aperture  34 R, and feeding portion  32 R and aperture  34 R are located on the inside of opening  21 R when feeding portion  32 R, aperture  34 R, and opening  21 R are viewed from the direction parallel to the direction in which planar light-emitting element  10 , wiring member  30 , and sealing sheets  21 ,  22  are superimposed on each other (when viewed two-dimensionally). Further detail of openings  21 L,  21 R will be described later. 
     (Wiring Member  30 ) 
     Referring to  FIG. 3 , wiring member  30  is electrically connected to planar light-emitting element  10  and is disposed between sealing sheets  21  and  22 . Specifically, wiring member  30  includes a substrate  31 , electrodes  32 ,  33 , and a protective film  34 . It is preferable that wiring member  30  has flexibility as a whole. Substrate  31  and protective film  34  (coverlay) have an outer shape smaller than sealing sheets  21 ,  22 . Protective film  34  has a pair of apertures  34 L,  34 R. Protective film  34  is provided so as to cover at least the portions located around feeding portions  32 R,  33 L (exposed portions) in electrodes  32 ,  33  and serves to protect electrodes  32 ,  33  and improve the sealing performance for the electrodes. 
     Electrodes  32 ,  33  are formed on substrate  31  by a deposition technique such as printing, vapor deposition, plating and sputtering. The thickness of electrodes  32 ,  33  is, for example, 0.1 μm to 10 μm. The material of electrodes  32 ,  33  is, for example, copper or nickel, or a laminate thereof. In addition to copper or nickel, or a laminate thereof, the surface thereof may be plated with gold. Electrodes  32 ,  33  may not be deposited but may be formed by affixing a metal thin foil such as copper foil tape on the surface of substrate  31  using conductive adhesive (for example, ACF: anisotropic conductive film). 
     (Electrode  32 ) 
     Electrode  32  includes a linear portion  32   a  extending longitudinally to match with the position and shape of feeding portion  19  of planar light-emitting element  10 , a rectangular portion  32   b  having feeding portion  32 R (exposed portion) inside thereof, and a connecting portion  32   c  connecting linear portion  32   a  with rectangular portion  32   b . When protective film  34  is disposed on substrate  31  and electrodes  32 ,  33 , linear portion  32   a  is not covered with protective film  34 . Feeding portion  19  of planar light-emitting element  10  is electrically connected to linear portion  32   a  of electrode  32  through not-shown conductive adhesive (ACF). Feeding portion  19  of planar light-emitting element  10  may be pressure-welded to linear portion  32   a  of electrode  32  without using conductive adhesive (ACF). 
     Feeding portion  32 R is a portion of electrode  32  that is exposable through aperture  34 R when protective film  34  is disposed on substrate  31  and electrode  32 . That is, feeding portion  32 R (exposed portion) is a portion that is disposed to be exposable on the outside through aperture  34 R and opening  21 R and connected to contact portion  41  of external wiring  40  ( FIG. 1 ) when protective film  34 , planar light-emitting element  10 , and sealing sheet  21  are disposed in order on electrode  32 . As used herein “exposable” is a concept that includes not only the state in which feeding portion  32 R is actually exposed through aperture  34 R and opening  21 R but also the state in which feeding portion  32 R in that state is further covered with another sealing member or conductive paste as necessary and not exposed. 
     The position of aperture  34 R provided in protective film  34  corresponds to the position of feeding portion  32 R of wiring member  30  (electrode  32 ) and the position of opening  21 R provided in sealing sheet  21  (see  FIG. 1 ). The size of aperture  34 R is smaller than the size of opening  21 R (the aperture area is smaller). The size of opening  21 R is smaller than the size of rectangular portion  32   b  of electrode  32 . Therefore, in the state in which protective film  34 , planar light-emitting element  10 , and sealing sheet  21  are disposed in order on electrode  32 , the edge portion that forms opening  21 R in sealing sheet  21  is located outside the position of aperture  34 R and located on a portion having a flat shape in the surface of protective film  34  (located on rectangular portion  32   b  with protective film  34  interposed). 
     Protective film  34  (specifically, the portion around aperture  34 R in protective film  34 ) is disposed on the surface of the portion located around feeding portion  32 R in rectangular portion  32   b  ( FIG. 3 ). The portion around aperture  34 R in protective film  34  is bonded to sealing sheet  21  through adhesive (see  FIG. 2 ). If the bonding force between protective film  34  and sealing sheet  21  is high, the sealing performance of planar light-emitting module  100  can be improved. Therefore, it is preferable that the portion located around feeding portion  32 R in rectangular portion  32   b  has a surface shape that has little or no step and is as flat as possible (with highest possible flatness). 
     (Electrode  33 ) 
     Electrode  33  includes a linear portion  33   a  extending longitudinally so as to match with the position and shape of feeding portion  18  of planar light-emitting element  10 , a rectangular portion  33   b  having a feeding portion  33 L (exposed portion) inside thereof, and a connecting portion  33   c  connecting linear portion  33   a  with rectangular portion  33   b . When protective film  34  is disposed on substrate  31  and electrodes  32 ,  33 , linear portion  33   a  is not covered with protective film  34 . Feeding portion  18  of planar light-emitting element  10  is electrically connected to linear portion  33   a  of electrode  33  through not-shown conductive adhesive (ACF). Feeding portion  18  of planar light-emitting element  10  may be pressure-welded to linear portion  33   a  of electrode  33  without using conductive adhesive (ACF). 
     Feeding portion  33 L is a portion of electrode  33  that is exposable through aperture  34 L when protective film  34  is disposed on substrate  31  and electrode  33 . That is, feeding portion  33 L (exposed portion) is a portion that is disposed so as to be exposable on the outside through aperture  34 L and opening  21 L and connected to contact portion  42  of external wiring  40  ( FIG. 1 ) when protective film  34 , planar light-emitting element  10 , and sealing sheet  21  are disposed in order on electrode  33 . As used herein “exposable” is a concept that includes not only the state in which feeding portion  33 L is actually exposed through aperture  34 L and opening  21 L but also the state in which feeding portion  33 L in that state is further covered with another sealing member or conductive paste as necessary and not exposed. 
     The position of aperture  34 L provided in protective film  34  corresponds to the position of feeding portion  33 L of wiring member  30  (electrode  33 ) and the position of opening  21 L provided in sealing sheet  21  (see  FIG. 1 ). The size of aperture  34 L is smaller than the size of opening  21 L (the aperture area is smaller). The size of opening  21 L is smaller than the size of rectangular portion  33   b  of electrode  33 . Therefore, in the state in which protective film  34 , planar light-emitting element  10 , and sealing sheet  21  are disposed in order on electrode  33 , the edge portion that forms opening  21 L in sealing sheet  21  is located outside aperture  34 L and is located on a portion having a flat shape in the surface of protective film  34  (located on rectangular portion  33   b  with protective film  34  interposed). 
     Protective film  34  (specifically, the portion around aperture  34 L in protective film  34 ) is disposed on the surface of the portion located around feeding portion  33 L in rectangular portion  33   b  ( FIG. 3 ). The portion around aperture  34 L in protective film  34  is bonded to sealing sheet  21  through adhesive (see  FIG. 2 ). If the bonding force between protective film  34  and sealing sheet  21  is high, the sealing performance of planar light-emitting module  100  can be improved. Therefore, it is preferable that the portion located around feeding portion  33 L in rectangular portion  33   b  has a surface shape that has little or no step and is as flat as possible (with highest possible flatness). 
     In the present embodiment, electrode  32  and electrode  33  of wiring member  30  extend on the same side of planar light-emitting element  10 , and feeding portions  32 R,  33 L (rectangular portions  32   b ,  33   b ) are disposed to be adjacent to each other. 
     (Operation and Effects) 
     Referring to  FIG. 5 , in planar light-emitting module  100 , feeding portions  33 L,  32 R of electrodes  33 ,  32  are exposed through apertures  34 L,  34 R provided in protective film  34  and openings  21 L,  21 R provided in sealing sheet  21  (first sealing sheet), respectively. Contact portions  42 ,  41  of external wiring  40  ( FIG. 1 ) can be electrically connected to feeding portions  33 L,  32 R, respectively. External wiring  40  is not positioned between the end portions of sealing sheets  21 ,  22 . 
     Unlike the case of PTD 1 (Japanese Laid-Open Patent Publication No. 2010-244698) mentioned earlier, in planar light-emitting module  100 , the presence of external wiring  40  does not result in formation of steps between the end portions of the sealing sheets  21 ,  22 , and the presence of external wiring  40  hardly affects the sealing performance. The end portions of sealing sheets  21 ,  22  can be bonded to each other appropriately, and the sealing performance can be obtained with sealing sheets  21 ,  22 . 
     Region RA shown by a hatching in  FIG. 5  is located around planar light-emitting element  10 , around substrate  31 , or around protective film  34 . This region RA indicates a portion where it is more likely than other portions that the thickness of planar light-emitting element  10 , the thickness of electrodes  32 ,  33 , and the thickness of protective film  34  produce steps when sealing sheets  21 ,  22  are bonded, and the presence of the steps results in a gap. If this region RA reaches outer edge EE ( FIG. 5 ) or openings  21 L,  21 R of sealing sheets  21 ,  22 , moisture or other substances easily intrude through the portion where region RA reaches. Planar light-emitting module  100  in the present embodiment, however, is not configured as such. 
     More specifically, when sealing sheet  21  is bonded to sealing sheet  22 , the portions around apertures  34 L,  34 R in protective film  34  are bonded to sealing sheet  21  through adhesive (see  FIG. 2 ). The edge portion that forms opening  21 L in sealing sheet  21  is located outside the position of aperture  34 L and located on a portion having a flat shape in the surface of protective film  34  (located on rectangular portion  33   b  with protective film  34  interposed). Similarly, the edge portion that forms opening  21 R in sealing sheet  21  is located outside the position of aperture  34 R and located on a portion having a flat shape in the surface of protective film  34  (located on rectangular portion  32   b  with protective film  34  interposed). Since a sealing structure that contains region RA in the inside by bonding between flat surfaces is thus achieved, it can be said that reduction of sealing performance is suppressed compared with the conventional sealing structure. 
     Unlike the case of Japanese Laid-Open Patent Publication No. H01-117295 (PTD 2) mentioned earlier, planar light-emitting module  100  does not employ a configuration having a conductor (electrode pin) inserted (pierced) into the sealing sheet. Compared with the case of PTD 2, the possibility that the sealing sheet is broken is low, and reliable sealing performance can be kept for a long time compared with the case of PTD 2. 
     Comparative Example 
     (Planar Light-Emitting Module  101 ) 
     Referring to  FIG. 6  to  FIG. 8 , a planar light-emitting module  101  in a comparative example will be described. Planar light-emitting module  101  differs from planar light-emitting module  100  of the first embodiment in that one opening  21 H is provided in sealing sheet  21 . 
     The edge portion that forms opening  21 H in sealing sheet  21  is located outside apertures  34 L,  34 R provided in protective film  34  ( FIG. 6 ). However, the edge portion that forms opening  21 H in sealing sheet  21  is not located on a portion having a flat shape in the surface of protective film  34 . Steps  32   d ,  33   d  ( FIG. 6 ) are formed on protective film  34  due the presence of electrodes  32 ,  33  (rectangular portions  32   b ,  33   b ). The edge portion that forms opening  21 H in sealing sheet  21  is disposed to extend across steps  32   d ,  33   d  (disposed to cross steps  32   d ,  33   d ) and is not located on a portion having a flat shape in the surface of protective film  34 . 
     Region RB shown by a hatching in  FIG. 8  is located around planar light-emitting element  10 , around substrate  31 , or around protective film  34 . In planar light-emitting module  101  of the comparative example, region RB reaches opening  21 H (see the portions surrounded by circles P 1 , P 2 ), and moisture or other substances easily intrude through the portion where region RB reaches. When planar light-emitting element  10  is sealed by sealing sheets  21 ,  22 , bonding of flat surfaces fails to be achieved, and sufficient sealing performance fails to be obtained. 
     Second Embodiment 
     Referring to  FIG. 10  and  FIG. 11 , a planar light-emitting module  102  in a second embodiment will be described. Planar light-emitting module  102  includes a wiring member  30 A instead of wiring member  30  (the first embodiment). Wiring member  30 A differs from wiring member  30  in that it does not include protective film  34 . 
     Feeding portion  32 R in planar light-emitting module  102  is a portion of electrode  32  that is exposable through opening  21 R when sealing sheet  21  is disposed on planar light-emitting element  10 , substrate  31 , and electrode  32 . The size of opening  21 R is smaller than the size of rectangular portion  32   b  of electrode  32 . When planar light-emitting element  10  is sandwiched and sealed between a pair of sealing sheets  21 ,  22  from above and below, feeding portion  32 R is located on the inside of opening  21 R when opening  21 R and feeding portion  32 R are viewed from the direction parallel to the direction in which planar light-emitting element  10  and sealing sheets  21 ,  22  are superimposed on each other (when viewed two-dimensionally). In the state in which sealing sheet  21  is disposed on electrode  32 , the edge portion that forms opening  21 R in sealing sheet  21  is located on a portion having a flat shape in the surface of rectangular portion  32   b  of electrode  32 . The portion around feeding portion  32 R in electrode  32  (rectangular portion  32   b ) is bonded to sealing sheet  21  through adhesive. It is preferable that the portion located around feeding portion  32 R in rectangular portion  32   b  has a surface shape that has little or no step and is as flat as possible (with highest possible flatness). 
     Feeding portion  33 L in planar light-emitting module  102  is a portion of electrode  33  that is exposable through opening  21 L when sealing sheet  21  is disposed on planar light-emitting element  10 , substrate  31 , and electrode  33 . The size of opening  21 L is smaller than the size of rectangular portion  33   b  of electrode  33 . When planar light-emitting element  10  is sandwiched and sealed between a pair of sealing sheets  21 ,  22  from above and below, feeding portion  33 L is located on the inside of opening  21 L when opening  21 L and feeding portion  33 L are viewed from the direction parallel to the direction in which planar light-emitting element  10  and sealing sheets  21 ,  22  are superimposed on each other (when viewed two-dimensionally). In the state in which sealing sheet  21  is disposed on electrode  33 , the edge portion that forms opening  21 L in sealing sheet  21  is located on a portion having a flat shape in the surface of rectangular portion  33   b  of electrode  32 . The portion around feeding portion  33 L in electrode  33  (rectangular portion  33   b ) is bonded to sealing sheet  21  through adhesive. It is preferable that the portion located around feeding portion  33 L in rectangular portion  33   b  has a surface shape that has little or no step and is as flat as possible (with highest possible flatness). 
     (Operation and Effects) 
     Referring to  FIG. 11 , in planar light-emitting module  102 , feeding portions  33 L,  32 R of electrodes  33 ,  32  are exposed through openings  21 L,  21 R, respectively, provided in sealing sheet  21  (first sealing sheet). Contact portions  42 ,  41  of external wiring  40  ( FIG. 1 ) can be electrically connected to feeding portions  33 L,  32 R, respectively. External wiring  40  is not located between the end portions of sealing sheets  21 ,  22 . The end portions of sealing sheets  21 ,  22  can be bonded to each other appropriately, and sealing performance by sealing sheets  21 ,  22  can be obtained. 
     Region RA shown by a hatching in  FIG. 11  is located around planar light-emitting element  10 , around substrate  31 , or around protective film  34 . Region RA does not reach the outer edge EE ( FIG. 11 ) of sealing sheets  21 ,  22  or openings  21 L,  21 R. When sealing sheet  21  is bonded to sealing sheet  22 , a sealing structure that contains region RA in the inside by bonding between flat surfaces can be achieved, and therefore it can be said that reduction of sealing performance is suppressed. Planar light-emitting module  102  does not have a configuration having a conductor (electrode pin) inserted (pierced) into the sealing sheet. Reliable sealing performance can be kept for a long time compared with the case of PTD 2. 
     To sum up the description above, the planar light-emitting module based on an aspect includes a first sealing sheet having an opening, a second sealing sheet bonded to the first sealing sheet, a planar light-emitting element disposed between the first sealing sheet and the second sealing sheet and sealed by the first sealing sheet and the second sealing sheet, and a wiring member disposed between the first sealing sheet and the second sealing sheet and electrically connected to the planar light-emitting element. The wiring member includes a substrate, an electrode formed on the substrate and having an exposed portion disposed so as to be exposable from the opening of the first sealing sheet, and a protective film having an aperture corresponding to the exposed portion and provided so as to cover at least the periphery of the exposed portion of the electrode. One exposed portion described above is exposable through one opening and one aperture described above. An edge portion that forms the opening in the first sealing sheet is located outside the aperture and is located on a portion having a flat shape in a surface of the protective film. 
     A planar light-emitting module according to another aspect includes a first sealing sheet having an opening, a second sealing sheet bonded to the first sealing sheet, a planar light-emitting element disposed between the first sealing sheet and the second sealing sheet and sealed by the first sealing sheet and the second sealing sheet, and a wiring member disposed between the first sealing sheet and the second sealing sheet and electrically connected to the planar light-emitting element. The wiring member includes a substrate and an electrode formed on the substrate and having an exposed portion disposed so as to be exposable from the opening of the first sealing sheet. One exposed portion described above is exposable through one opening described above. An edge portion that forms the opening in the first sealing sheet is located on a portion having a flat shape in the surface of the electrode. 
     In the planar light-emitting module, preferably, the first sealing sheet, the second sealing sheet, the planar light-emitting element, and the wiring member have flexibility. 
     In the configuration above, the portion that forms the opening in the first sealing sheet is bonded to a portion having a flat surface shape (in other words, a portion where steps are not formed). Since a sealing structure can be achieved by bonding between flat surfaces, the configuration above can suppress reduction of sealing performance compared with the conventional sealing structures. 
     Although embodiments have been described above, the foregoing disclosure is illustrative in all respects and not limitative. The technical scope of the present invention is shown by the claims and it is intended that all equivalents and modifications within the scope of the claims are embraced. 
     REFERENCE SIGNS LIST 
     
         
         
           
               10  planar light-emitting element,  10 S front surface,  11  transparent substrate,  12  barrier layer,  13  anode,  14  emissive layer,  15  cathode,  16  sealing member,  17  insulating layer,  18 ,  19  feeding portion,  21  sealing sheet (first sealing sheet),  21 H,  21 L,  21 R opening,  22  sealing sheet (second sealing sheet),  30 ,  30 A wiring member,  31 ,  43  substrate,  32 ,  33  electrode,  32   a ,  33   a  linear portion,  32   b ,  33   b  rectangular portion,  32   c ,  33   c  connecting portion,  32   d ,  33   d  step,  32 R,  33 L feeding portion (exposed portion),  34  protective film,  34 L,  34 R aperture,  40  external wiring,  41 ,  42  contact portion,  100 ,  101 ,  102  planar light-emitting module, EE outer edge, P 1 , P 2  circle, RA, RB region.