Patent Document

BACKGROUND 
       [0001]    The present disclosure relates to a light emitting unit having plural kinds of light emitting elements having different light emitting wavelengths, and a display device having the light emitting unit. 
         [0002]    Recently, an LED display using LEDs (Light Emitting Diodes) as display pixels is spotlighted as a light and thin display. The LED display has no viewing angle dependence where contrast or color tone changes according to a viewing angle, and has a fast response speed when color changes. However, it is necessary to mount several million LED chips on a wiring substrate with a good production rate and connect their wires. For this reason, there is demanded a method capable of realizing a simple and easy process with a high production rate. 
         [0003]    For example, in a method disclosed in Japanese Unexamined Patent Application Publication No. 2007-19467, first, color LEDs are transcribed on a transcribing substrate with the same pitch, and each of the plurality of colors of LEDs is covered by a resin to form a light emitting unit. After that, each light emitting unit is transcribed on a display panel substrate in a matrix form. By doing so, a display panel is manufactured in a convenient and easy way. 
       SUMMARY 
       [0004]    However, in the light emitting unit disclosed in Japanese Unexamined Patent Application Publication No. 2007-19467, the light generated from each LED is output from the surface of the light emitting unit to the outside and propagates in the resin of the light emitting unit. At this time, in a case where the light propagating in the resin is a blue light with a short wavelength, if the blue light is incident to a red LED, the material included in the red LED (for example, polyimide) is degraded, so that there is a problem in that the optical output of the red LED changes. In addition, in a case where the light propagating in the resin is a green light, if the green light is incident to a red LED, the red LED may be excited and emitted by the green light. As a result, there are problems such as the creation of a crosstalk on a displayed image, the change of color temperature, and the decrease of a color reproduction range. 
         [0005]    There is a demand for providing a light emitting unit capable of decreasing a bad influence caused by the light propagating in a resin of the light emitting unit, and a display device having the same. 
         [0006]    According to an embodiment of the present disclosure, there is provided a light emitting unit includes plural kinds of light emitting elements with different light emitting wavelengths. Among the plural kinds of light emitting elements, at least one kind of light emitting element includes a semiconductor layer configured by laminating a first conductive layer, an active layer and a second conductive layer. The light emitting element includes a first electrode electrically connected to the first conductive layer, and a second electrode electrically connected to the second conductive layer. Further, as the semiconductor layer has the side surface exposed by the first conductive layer, the active layer and the second conductive layer, the light emitting element includes a first insulation layer contacting at least an exposed surface of the active layer in the surface of the semiconductor layer, and a metal layer contacting at least a surface, which is opposite to the exposed surface of the active layer, in the surface of the first insulation layer. The metal layer is electrically separated from the first electrode and the second electrode. 
         [0007]    The display device according to the present disclosure includes a display panel having a plurality of light emitting units, and a driving circuit for driving each light emitting unit based on an image signal. In the display device of the present disclosure, each light emitting unit has the same components as the above light emitting unit. 
         [0008]    In the light emitting unit and the display device according to the present disclosure, at the side surface of at least one kind of light emitting element among the plural kinds of light emitting elements, the first insulation layer contacting at least the exposed surface of the active layer and the metal layer contacting at least a surface opposite to the exposed surface of the active layer in the surface of the first insulation layer are installed. By doing so, among the light generated from the active layer, the light propagating toward the inside of the lamination surface may be reflected by the metal layer installed at the side surface of the light emitting element to disturb light incidence to an adjacent light emitting element. Here, since the metal layer is electrically separated from the first electrode and the second electrode, there is very little chance that the first electrode and the second electrode are shorted through the metal layer. For this reason, there is also very little change that the metal layer provided at the side surface gives a bad influence on the pressure resistance of the light emitting element. 
         [0009]    However, in the present disclosure, the first insulation layer and the metal layer preferably covers at least the entire side surface of the light emitting element. In this case, among the light generated from the active layer, not only the light propagating toward the inside of the lamination surface but also the light propagating in an inclined direction are reflected by the metal layer installed at the side surface of the light emitting element so that the light incidence to an adjacent light emitting element may be further disturbed. 
         [0010]    In addition, in the present disclosure, the first electrode is a metal electrode present at the surface of the first conductive layer and formed to contact the surface at an opposite side to the active layer, and the first insulation layer and the metal layer may be formed from a region opposite to the side surface over a region opposite to the first electrode. In this case, since a part of the first electrode and a part of the metal layer overlap each other with the first insulation layer being interposed therebetween, the light from the active layer may not easily leak out directly through the gap (interval) between the first electrode and the metal layer. 
         [0011]    In addition, in the present disclosure, a part of the surface of a portion of the first insulation layer, which is formed in a region opposite to the first electrode, preferably becomes an exposed surface not covered by the metal layer so that a second insulation layer is formed from the exposed surface over the surface of the metal layer. Further, in the above case, a part of the surface of the first electrode preferably becomes an exposed surface not covered by the first insulation layer, the metal layer and the second insulation layer so that a pad electrode is formed from the exposed surface over the surface of the first insulation layer and the surface of the second insulation layer. In this case, since a part of the metal layer and a part of the pad electrode overlap each other with the second insulation layer being interposed therebetween, the light from the active layer substantially does not leak out through the gap (interval) between the first electrode and the metal layer, and the gap (interval) between the first electrode and the pad electrode. 
         [0012]    In addition, in the present disclosure, in the case where the plural kinds of light emitting elements includes a light emitting element emitting a blue color, a light emitting element emitting a green color and a light emitting element emitting a red color, among these three kinds of light emitting elements, at least the light emitting element emitting a blue color and the light emitting element emitting a green color preferably have the metal layer. 
         [0013]    According to the light emitting unit and the display device of an embodiment of the present disclosure, since, among the light generated from the active layer, the light propagating toward the inside of the lamination surface is reflected by the metal layer installed at the side surface of the light emitting element to disturb light incidence to an adjacent light emitting element, the bad influence caused by the light propagating in the light emitting unit may be reduced. In particular, in the case where the first insulation layer and the metal layer cover at least the entire side surface of the light emitting element, among the light generated from the active layer, not only the light propagating toward the inside of the lamination surface but also the light propagating in an inclined direction may be reflected at the metal layer, and so the bad influence caused by the light propagating in the resin of the light emitting unit may be greatly reduced. 
         [0014]    However, in the light emitting unit and the display device of an embodiment of the present disclosure, in order to avoid that the first electrode and the metal layer are shorted, a gap (interval) is present between the metal layer and the first electrode. However, in a case where the first insulation layer and the metal layer are formed from a region of the semiconductor layer opposite to the side surface over a region opposite to the first electrode, a part of the first electrode and a part of the metal layer overlap each other with the first insulation layer being interposed therebetween. For this reason, the light from the active layer does not leak out through the gap (interval) between the first electrode and the metal layer. By doing so, a bad influence caused by the light propagating in the light emitting unit may be reduced without giving a bad influence on the pressure resistance of the light emitting element. 
         [0015]    In addition, in the light emitting unit and the display device of an embodiment of the present disclosure, in the case where the second insulation layer is formed from the exposed surface of the first insulation layer over the surface of the metal layer, and further the pad electrode is formed from the exposed surface of the first electrode over the surface of the first insulation layer and the surface of the second insulation layer, since a part of the metal layer and a part of the pad electrode overlap each other with the second insulation layer being interposed therebetween, there is very little change that the light from the active layer leaks out through the gap (interval) between the first electrode and the metal layer, and between the gap (interval) between the metal layer and the pad electrode. By doing so, it is possible to prevent shorting between the metal layer and the first electrode (or, the pad electrode) more securely and to further reduce the bad influence caused by the light propagating in the light emitting unit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIGS. 1A and 2B  are a perspective view and a cross-sectional view showing an example of a configuration of a light emitting unit according to a first embodiment of the present disclosure; 
           [0017]      FIGS. 2A and 2B  are cross-sectional views showing an example of a configuration of an optic element of  FIGS. 1A and 1B ; 
           [0018]      FIGS. 3A and 3B  are cross-sectional views showing another example of a configuration of the optic element of  FIGS. 1A and 1B ; 
           [0019]      FIGS. 4A and 4B  are a perspective view and a cross-sectional view showing an example of a configuration of a light emitting unit according to a second embodiment of the present disclosure; 
           [0020]      FIGS. 5A and 5B  are cross-sectional views showing an example of a configuration of an optic element of  FIGS. 4A and 4B ; 
           [0021]      FIGS. 6A and 6B  are cross-sectional views showing another example of a configuration of the optic element of  FIGS. 4A and 4B ; 
           [0022]      FIGS. 7A and 7B  are cross-sectional views showing a modification of a configuration of the optic element of  FIGS. 4A and 4B ; 
           [0023]      FIG. 8  is a perspective view showing an example of a configuration of a display device according to a third embodiment of the present disclosure; and 
           [0024]      FIG. 9  is a plan view showing an example of a layout of a surface of a mounting substrate of  FIG. 8 . 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0025]    Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In addition, the following description will be set forth in the following order: 
       1. First Embodiment 
     A Light Emitting Unit 
       [0026]    An example where element electrodes are installed at upper and lower surfaces. 
       2. Second Embodiment 
     A Light Emitting Unit 
       [0027]    An example where an element electrode is installed at only a lower surface. 
       3. Third Embodiment 
     A Display Device 
       [0028]    An example where the light emitting unit of the above embodiments is installed as a pixel. 
       1. First Embodiment 
     Configuration 
       [0029]    First, a light emitting unit  1  according to a first embodiment of the present disclosure will be described.  FIG. 1A  is a perspective view showing an example of a general configuration of the light emitting unit  1 .  FIG. 1B  shows an example of a cross-sectional configuration of the light emitting unit  1  of  FIG. 1A  in an arrow direction IB-IB. The light emitting unit  1  may be very usefully applied as a display pixel of a display device which is a so-called LED display, and is a small package where a plurality of light emitting elements are surrounded by a thin resin. 
       Light Emitting Element  10   
       [0030]    As shown in  FIG. 1A , the light emitting unit  1  has three light emitting elements  10 . Each light emitting element  10  is a solid light emitting element emitting light of a predetermined wavelength range from a surface thereof, and in detail is an LED chip. The LED chip represents a chip obtained by cutting a wafer whose crystal has grown, which is not in a package type surrounded by a molding resin or the like. The LED chip is called a micro LED since it has a size of, for example, 5 μm or above and 100 mm or less. The planar shape of the LED chip is, for example, substantially cubic. The LED chip has a thin film shape, and an aspect ratio (height/width) of the LED chip is, for example, equal to or greater than 0.1 and less than 1. 
         [0031]    Each light emitting element  10  is disposed in the light emitting unit  1 , and for example, as shown in  FIG. 1A , is disposed in a row together with other light emitting elements  10  with a predetermined gap (interval) being interposed therebetween. At this time, the light emitting unit  1  has, for example, an elongated shape extending in an array direction of the light emitting element  10 . A gap between two adjacent light emitting elements  10  is, for example, equal to or greater than the size of each light emitting element  10 . In addition, on occasions, the gap may be smaller than the size of each light emitting element  10 . 
         [0032]    The light emitting elements  10  are respectively configured to emit lights of different wavelength ranges. For example, as shown in  FIG. 1A , three light emitting elements  10  are composed of a light emitting element  10 G emitting a light of a green band, a light emitting element  10 R emitting a light of a red band, and a light emitting element  10 B. For example, in a chase where the light emitting unit  1  has an elongated shape extending in the array direction of the light emitting element  10 , the light emitting element  10 G is, for example, disposed near the short side of the light emitting unit  1 , and the light emitting element  10 B is disposed, for example, near a short side other than the short side of the light emitting unit  1  which is near the light emitting element  10 G. The light emitting element  10 R is disposed, for example, between the light emitting element  10 G and the light emitting element  10 B. In addition, locations of the light emitting elements  10 R,  10 G, and  10 B are respectively not limited to the above, but hereinafter, location relationship of other components may be described on the assumption that the light emitting elements  10 R,  10 G, and  10 B are disposed at the above locations. 
         [0033]    As shown in  FIG. 2A , for example, each light emitting element  10  has a semiconductor layer where a first conductive layer  11 , an active layer  12  and a second conductive layer  13 Are laminated in order. In the light emitting element  10 G and  10 B, the first conductive layer  11 , the active layer  12  and the second conductive layer  13 Are made of, for example, InGaN-based semiconductor material. Meanwhile, in the light emitting element  10 R, the first conductive layer  11 , the active layer  12  and the second conductive layer  13 Are made of, for example, AlGaInP-based semiconductor material. 
         [0034]    A second electrode  15  is installed at the surface of the second conductive layer  13  (namely, a light emitting surface S 2 ). The second electrode  15  is made of, for example, Ti (titan)/Pt (platinum)/Au (gold), for the light emitting element  10 G and  10 B. The second electrode  15  is made of, for example, AuGe (an alloy of gold and germanium)/Ni (nickel)/Au, for the light emitting element  10 R. The second electrode  15  contacts the second conductive layer  13 And is electrically connected to the second conductive layer  13 . In other words, the second electrode  15  makes an ohmic contact with the second conductive layer  13 . Meanwhile, at the lower surface of the first conductive layer  11 , a first electrode  14  is installed. The first electrode  14  is a metal electrode. The first electrode  14  is made of, for example, Ti/Pt/Au for the light emitting element  10 G and  10 B. The first electrode  14  is made of, for example, AuGe/Ni/Au for the light emitting element  10 R. The first electrode  14  contacts the first conductive layer  11  and is electrically connected to the first conductive layer  11 . In other words, the first electrode  14  makes an ohmic contact with the first conductive layer  11 . The first electrode  14  and the second electrode  15  may be configured as a single electrode together or may be configured as a plurality of electrodes. In addition, hereinafter, as shown in  FIG. 2A , it is assumed that the first electrode  14  and the second electrode  15  are a single electrode together. The first electrode  14  and the second electrode  15  may be configured to include, for example, metal material with high reflectivity such as Ag (silver), Al (aluminum) or the like. 
         [0035]    A side surface S 1  of each light emitting element  10  (in detail, a semiconductor layer) is, for example, an inclined surface crossing a lamination direction, as shown in  FIG. 2A , in detail an inclined surface where a cross section of the corresponding light emitting element  10  has an inverse trapezoidal shape. As described above, as the side surface S 1  has a tapered shape, the light emitting efficiency in the front direction may be improved. In addition, the side surface S 1  may be, for example, a vertical surface perpendicular to the lamination direction, as shown in  FIG. 2B . 
         [0036]    As shown in  FIGS. 2A and 2B , each light emitting element  10  has, for example, a laminated body composed of a first insulation layer  16 , a metal layer  17 , a second insulation layer  18  and a pad electrode  19 . The laminated body is a layer formed from the side surface S 1  of the semiconductor layer over the lower surface. In the laminated body, at least the first insulation layer  16 , the metal layer  17  and the second insulation layer  18  are respectively thin layers, for example, formed by a thin film forming process such as CVD, deposition, sputtering or the like. In other words, in the laminated body, at least the first insulation layer  16 , the metal layer  17  and the second insulation layer  18  are not formed by a thick film forming process such as spin coating, resin molding, potting or the like. 
         [0037]    The first insulation layer  16 , the metal layer  17  and the second insulation layer  18  covers at least the entire side surface S 1  to be formed from a region opposite to the side surface S 1  over a part of a region opposite to the first electrode  14 . The first insulation layer  16  is for electric insulation between the metal layer  17  and the semiconductor layer. The first insulation layer  16  is formed, among the side surface S 1 , from the end portion of the light emitting element  10  at the light emitting surface S 2  side over the outer circumference of the surface of the first electrode  14 . In other words, the first insulation layer  16  is formed to contact the entire side surface S 1  of the light emitting element  10  and is further formed to contact the outer circumference of the surface of the first electrode  14 . The first insulation layer  16  is made of transparent material with respect to the light generated from the active layer  12 , for example, SiO 2 , SiN, Al 2 O 3 , TiO 2 , TiN or the like. The first insulation layer  16  has, for example, a thickness of about 0.1 μm to 1 μm, substantially regular. In addition, the first insulation layer  16  may have irregularity in thickness due to a production error. 
         [0038]    The metal layer  17  is for covering or reflecting the light generated from the active layer  12 . The metal layer  17  is formed to contact the surface of the first insulation layer  16 . The metal layer  17  is formed, at the surface of the first insulation layer  16 , from the end portion at the light emitting surface S 2  side to a place slightly rearward from the end portion at the first electrode  14  side. In other words, the first insulation layer  16  has an exposed surface  16 A not covered by the metal layer  17 , at a portion opposite to the first electrode  14 . 
         [0039]    The end portion of the metal layer  17  at the light emitting surface S 2  side is formed at the same surface of the end portion of the first insulation layer  16  at the light emitting surface S 2  side (in other words, the same surface as the light emitting surface S 2 ). Meanwhile, the end portion of the metal layer  17  at the first electrode  14  side is formed at a region opposite to the first electrode  14  to partially overlap the metal layer  17  with the first insulation layer  16  being interposed therebetween. In other words, the metal layer  17  is insulated (electrically separated) from the semiconductor layer, the first electrode  14  and the second electrode  15  by the first insulation layer  16 . 
         [0040]    Between the end portion of the metal layer  17  at the first electrode  14  side and the metal layer  17 , a gap (interval) is present as much as the thickness of the first insulation layer  16 . However, since the end portion of the metal layer  17  at the first electrode  14  side and the first electrode  14  overlap each other with the first insulation layer  16  being interposed therebetween, the gap (interval) may not be visually recognized in the lamination direction (namely, in the thickness direction). Further, the thickness of the first insulation layer  16  is just several μm at most. Therefore, the light generated from the active layer  12  is substantially not emitted to the outside directly through the gap (interval). 
         [0041]    The metal layer  17  is made of material covering or reflecting the light generated from the active layer  12 , for example, Ti, Al, Cu, Au, Ni, or their alloys. The metal layer  17  has, for example, a thickness of about 0.1 μm to 1 μm, substantially regular. In addition, the metal layer  17  may have irregularity in thickness caused by a production error. 
         [0042]    The second insulation layer  18  is for preventing a conductive material (for example, solder, plate, sputtering metal) joining the pad electrode  19  and a mounting substrate to each other and the metal layer  17  from being shorted, when the light emitting unit  1  is mounted to the mounting substrate (not shown). The second insulation layer  18  is formed to contact the surface of the metal layer  17  and the surface of the first insulation layer  16  (the exposed surface  16 A). The second insulation layer  18  is formed on the entire surface of the metal layer  17  and is formed on all or a part of the exposed surface  16 A of the first insulation layer  16 . In other words, the second insulation layer  18  is formed from the exposed surface  16 A of the first insulation layer  16  over the surface of the metal layer  17  so that the metal layer  17  is covered by the first insulation layer  16  and the second insulation layer  18 . The second insulation layer  18  is made of, for example, SiO 2 , SiN, Al 2 O 3 , TiO 2 , TiN or the like. In addition, the second insulation layer  18  may be made of a plurality of materials among the above materials. The second insulation layer  18  has, for example a thickness of about 0.1 μm to 1 μm, substantially regular. In addition, the second insulation layer  18  may have irregularity in thickness caused by a production error. 
         [0043]    The pad electrode  19  is an electrode drawn from the first electrode  14  (namely, a drawn electrode). The pad electrode  19  is formed from the exposed surface  14 A of the first electrode  14  over the surface of the first insulation layer  16  and the surface of the second insulation layer  18 . The pad electrode  19  is electrically connected to the first electrode  14  so that a part of the pad electrode  19  overlaps a part of the metal layer  17  with the second insulation layer  18  being interposed therebetween. In other words, the pad electrode  19  is insulated (electrically separated) from the metal layer  17  by the second insulation layer  18 . The pad electrode  19  is made of material reflecting the light generated from the active layer  12  with high reflectivity, for example, Ti, Al, Cu, Au, Ni, or their alloys. In addition, the pad electrode  19  may be formed a plurality of materials among the above materials. 
         [0044]    Between the end portion of the pad electrode  19  and the metal layer  17 , a gap (interval) is present as much as the thickness of the second insulation layer  18 . However, since the end portion of the pad electrode  19  and the end portion of the metal layer  17  at the first electrode  14  side overlap each other, the gap (interval) may not be visually recognized in the lamination direction (namely, in the thickness direction). Further, the thickness of the second insulation layer  18  is just several μm at most. Further, since the end portion of the first electrode  14  and the metal layer  17  at the first electrode  14  side and the end portion of the pad electrode  19  overlap each other, the passage communicating with the outside from the active layer  12  through the first insulation layer  16  and the second insulation layer  18  is bent in an S shape. In other words, the passage where the light generated from the active layer  12  may pass is curved in as S shape. From the above, the first insulation layer  16  and the second insulation layer  18  used for insulating the metal layer  17  may be a passage communicating with the outside from the active layer  12 , but this passage may be recognized as being configured so that the light generated from the active layer  12  may substantially not leak out since it is extremely narrow and has an S shape. 
         [0045]    In addition, from the viewpoint that it is prevented for the light generated from the active layer  12  to be directly incident on another light emitting element  10 , the metal layer  17  may not cover a portion of the active layer  12  other than the exposed surface, if it is formed on the surface of the first insulation layer  16  to contact at least a surface of the active layer  12  opposite to the exposed surface. At this time, the first insulation layer  16  may not cover the entire side surface S 1 , if it is formed on the surface of the semiconductor layer to cover at least the exposed surface of the active layer  12 . In addition, the metal layer  17  may not cover the entire side surface S 1 , if it does not cover at least a surface at an adjacent light emitting element  10  side, in the side surface S 1 . At this time, the first insulation layer  16  may not cover the entire side surface S 1  if it does not cover at least a side at an adjacent light emitting element  10  side, in the side surface S 1 . In addition, from the viewpoint that it is prevented for the first conductive layer  11  and the second conductive layer  13  from being shorted through the metal layer  17 , in any case, it is preferable that the metal layer  17  is not drawn at the surface of the first insulation layer  16 . 
         [0046]    In addition, in the case where three light emitting elements  10  included in the light emitting unit  1  are light emitting elements  10 R,  10 G and  10 B, it is preferred that all light emitting elements  10  have the above laminated body, but any light emitting element  10  may not have the above laminated body. For example, among three light emitting elements  10 , the light emitting element  10 B emitting a light of a shortest wavelength may have the above laminated body. In addition, for example, among three light emitting elements  10 , the light emitting elements  10  (in detail, the light emitting elements  10 G and  10 B) other than the light emitting element  10 R emitting a light of a longest wavelength may have the above laminated body. 
         [0047]      FIGS. 3A and 3B  shows an example of a cross-sectional configuration of the light emitting element  10  where the above laminated body is not installed. In addition, in  FIGS. 3A and 3B , the light emitting element  10 R emitting a light of a longest wavelength is exemplified as the light emitting element  10  where the above laminated body is not installed. The light emitting element  10  is, for example, configured so that the metal layer  17  and the second insulation layer  18  are excluded from the above laminated body as shown in  FIGS. 3A and 3B . In addition, the light emitting element  10  may be configured, on occasions, to exclude even the first insulation layer  16  and the pad electrode  19 , so that the entire first electrode  14  is exposed. 
         [0000]    Insulating body  20  and Terminal Electrodes  31  and  32   
         [0048]    As shown in  FIG. 1A , the light emitting unit  1  includes a chip-type insulating body  20  covering each light emitting element  10  and terminal electrodes  31  and  32  electrically connected to each light emitting element  10 . The terminal electrodes  31  and  32  are disposed at the bottom surface side of the insulating body  20 . 
         [0049]    The insulating body  20  surrounds and retains each light emitting element  10  at least at the side surface of each light emitting element  10 . The insulating body  20  is made of, for example, resin material such as silicon, acryl, epoxy or the like. The insulating body  20  may include other material such as polyimide or the like in part. The insulating body  20  is formed to contact a region where the second electrode  15  is not formed, among the side surface of each light emitting element  10  and the surface of each light emitting element  10 . The insulating body  20  has an elongated shape (for example, a rectangular parallelepiped shape) extending in the array direction of each light emitting element  10 . The height of the insulating body  20  is greater than the height of each light emitting element  10 , and the lateral width (the width in the short side direction) of the insulating body  20  is wider than the width of each light emitting element  10 . The size of the insulating body  20  is, for example, 1 mm or less. The insulating body  20  has a thin film shape. The aspect ratio (maximum height/maximum lateral width) of the insulating body  20  is decreasing when the light emitting unit  1  is transcribed so that the light emitting unit  1  does not lie, to be, for example, ⅕ or less. 
         [0050]    As shown in  FIGS. 1A and 1B , the insulating body  20  has, for example, an opening  20 A at a location corresponding to a side just above each light emitting element  10 . At the bottom surface of each opening  20 A, at least the second electrode  15  (not shown in  FIGS. 1A  and  1 B) is exposed. In addition, as shown in  FIGS. 1A and 1B , the insulating body  20  has, for example, an opening  20 B at a location corresponding to a side just below each light emitting element  10 . At the bottom surface of each opening  20 B, at least the pad electrode  19  (on occasions, the first electrode  14 ) (not shown in  FIGS. 1A and 1B ) is exposed. 
         [0051]    The pad electrode  19  (or, the first electrode  14 ) is connected to the terminal electrode  31  through a predetermined conductive member (for example, solder and plated metal). Meanwhile, the second electrode  15  is connected to the terminal electrode  32  through a bump  33  and a connection portion  34  shown in  FIG. 1A . The bump  33  is a pillar-shaped conductive member buried in the insulating body  20 , and the connection portion  34  is a band-shaped conductive member formed on the surface of the insulating body  20 . In addition, the second electrode  15  may be connected to the terminal electrode  32  through a conductive member other than the bump  33  and the connection portion  34 . The terminal electrodes  31  and  32  are configured to mainly include, for example, Cu (copper). A part of the surfaces of the terminal electrodes  31  and  32  may be coated with, for example, material not easily oxidized, such as Au (gold). 
       Effect 
       [0052]    Next, the effects of the light emitting unit  1  of this embodiment will be described. 
         [0053]    In this embodiment, the above laminated body is installed at the light emitting element  10 B emitting a light of a shortest wavelength, among three light emitting elements  10 . By doing so, among the light generated from the active layer  12  in the light emitting element  10  at which the above laminated body is installed, the light propagating toward the inside of the lamination surface may be reflected by the metal layer  17  installed at the side surface of the light emitting element  10  and disturb light incidence to an adjacent light emitting element  10 . As a result, a bad influence (for example, degradation of the resin without a light resistance against a blue light) caused by the light propagating in the insulating body  20  of the light emitting unit  1  may be decreased. In addition, in a case where the above laminated body is installed to at least two light emitting elements  10 B and  10 G among three light emitting elements  10 , the excitation of the light emitting element  10 R caused by the light generated from the light emitting element  10 B or the light emitting element  10 G may also be disturbed. Therefore, the change of color temperature or the range of color reproduction may be reduced. 
         [0054]    In particular, in a case where the first insulation layer  16  and the metal layer  17  cover at least the entire side surface S 1  of the light emitting element  10 , among the light generated from the active layer  12 , not only the light propagating toward the inside of the lamination surface but also the light propagating in an inclined direction may be reflected to the metal layer  17 . As a result, a bad influence caused by the light propagating in the insulating body  20  of the light emitting unit  1  may be greatly reduced. 
         [0055]    In addition, since the metal layer  17  installed at the side surface S 1  is electrically separated from the first electrode  14  and the second electrode  15 , there is very little change that the first electrode  14  and the second electrode  15  are shorted through the metal layer  17 . For this reason, there is also very little change that the metal layer  17  installed at the side surface S 1  gives a bad influence on a pressure resistance of the light emitting element  10 . 
         [0056]    However, in this embodiment, in order to avoid that the first electrode  14  and the metal layer  17  are shorted, a gap (interval) is present between the metal layer  17  and the first electrode  14 . However, since the first insulation layer  16  and the metal layer  17  are formed from a region of the semiconductor layer opposite to the side surface S 1  over a region opposite to the first electrode  14 , a part of the first electrode  14  and a part of the metal layer  17  overlap each other with the first insulation layer  16  being interposed therebetween. For this reason, the light from the active layer  12  does not directly leak out to the insulating body  20  through the gap (interval) between the first electrode  14  and the metal layer  17 . By doing so, a bad influence caused by the light propagating in the insulating body of the light emitting unit  1  may be reduced without giving a bad influence on the pressure resistance of the light emitting element  10 . 
         [0057]    In addition, in this embodiment, the second insulation layer  18  is formed from the exposed surface  16 A of the first insulation layer  16  over the surface of the metal layer  17 , and further the pad electrode  19  is formed from the exposed surface  14 A of the first electrode  14  over the surface of the first insulation layer  16  and the surface of the second insulation layer  18 . By doing so, since a part of the metal layer  17  and a part of the pad electrode  19  overlap each other with the second insulation layer  18  being interposed therebetween, there is very little change that the light from the active layer  12  leaks out to the insulating body  20  through the gap (interval) between the first electrode  14  and the metal layer  17 , and between the gap (interval) between the metal layer  17  and the pad electrode  19 . As a result, it is possible to prevent shorting between the metal layer  17  and the first electrode  14  (or, the pad electrode  19 ) more securely and to further reduce the bad influence caused by the light propagating in the insulating body  20  of the light emitting unit  1 . 
       2. Second Embodiment 
     Configuration 
       [0058]    Next, a light emitting unit  2  according to a second embodiment of the present disclosure will be described.  FIG. 4A  is a perspective view showing an example of a general configuration of the light emitting unit  2 .  FIG. 4B  shows an example of a cross-sectional configuration of the light emitting unit  2  of  FIG. 4A  in an arrow direction IVB-IVB. The light emitting unit  2  may be very suitably applied as a display pixel of a display device which is a so-called LED display, and is a small package where a plurality of light emitting elements are surrounded by a thin resin, similar to the light emitting unit  1  of the former embodiment. 
       Light Emitting Element  40   
       [0059]    As shown in  FIG. 4A , the light emitting unit  2  has three light emitting elements  40 . Each light emitting element  40  is a solid light emitting element emitting light of a predetermined wavelength range from a surface thereof, and in detail is an LED chip. The LED chip represents a chip obtained by cutting a wafer whose crystal has grown, which is not in a package type surrounded by a molding resin or the like. The LED chip is called a micro LED since it has a size of, for example, 5 μm or above and 100 mm or less. The planar shape of the LED chip is, for example, substantially cubic. The LED chip has a thin film shape, and an aspect ratio (height/width) of the LED chip is, for example, equal to or greater than 0.1 and less than 1. 
         [0060]    Each light emitting element  40  is disposed in the light emitting unit  2 , and for example, as shown in  FIG. 4A , is disposed in a row together with other light emitting elements  40  with a predetermined gap (interval) being interposed therebetween. At this time, the light emitting unit  2  has, for example, an elongated shape extending in an array direction of the light emitting element  40 . A gap between two adjacent light emitting elements  40  is, for example, equal to or greater than the size of each light emitting element  40 . In addition, on occasions, the gap may be smaller than the size of each light emitting element  40 . 
         [0061]    The light emitting elements  40  are respectively configured to emit lights of different wavelength ranges. For example, as shown in  FIG. 4A , three light emitting elements  40  are composed of a light emitting element  40 G emitting a light of a green band, a light emitting element  40 R emitting a light of a red band, and a light emitting element  40 B. For example, in a chase where the light emitting unit  2  has an elongated shape extending in the array direction of the light emitting element  40 , the light emitting element  40 G is, for example, disposed near the short side of the light emitting unit  2 , and the light emitting element  40 B is disposed, for example, near a short side other than the short side of the light emitting unit  2  which is near the light emitting element  40 G. The light emitting element  40 R is disposed, for example, between the light emitting element  40 G and the light emitting element  40 B. In addition, locations of the light emitting elements  40 R,  40 G, and  40 B are respectively not limited to the above, but hereinafter, location relationship of other components may be described on the assumption that the light emitting elements  40 R,  40 G, and  40 B are disposed at the above locations. 
         [0062]    As shown in  FIG. 5A , for example, each light emitting element  40  has a semiconductor layer where a first conductive layer  41 , an active layer  42  and a second conductive layer  43  are laminated in order. In addition,  FIG. 5A  shows an example of a cross-sectional configuration when the light emitting element  40  is cut in a direction perpendicular to the line VA-VA of  FIG. 4A . In the light emitting element  40 G and  40 B, the first conductive layer  41 , the active layer  42  and the second conductive layer  43 Are made of, for example, InGaN-based semiconductor material. Meanwhile, in the light emitting element  40 R, the first conductive layer  41 , the active layer  42  and the second conductive layer  43 Are made of, for example, AlGaInP-based semiconductor material. 
         [0063]    In the semiconductor layer of each light emitting element  40 , a part of the second conductive layer  43 And a portion including the active layer  42  and the first conductive layer  41  become a pillar-shaped mesa portion  40 - 1 . In the semiconductor layer, at the bottom side of the mesa portion  40 - 1 , a flat surface where the second conductive layer  43  is exposed is spread, and a second electrode  45  is formed at a part of the flat surface. The second electrode  45  is a metal electrode. The second electrode  45  is made of, for example, Ti/Pt/Au for the light emitting elements  40 G and  40 B. The second electrode  45  is made of, for example, AuGe/Ni/Au for the light emitting element  40 R. The second electrode  45  contacts the second conductive layer  43 And is electrically connected to the second conductive layer  43 . In other words, the second electrode  45  makes an ohmic contact with the second conductive layer  43 . In addition, the surface of the second conductive layer  43  (namely, the surface of the semiconductor opposite to the mesa portion  40 - 1 ) becomes a light emitting surface S 4  so that a light shielding structure such as an electrode is not installed. At the surface of the mesa portion  40 - 1  (namely, the surface of the first conductive layer  41 ), a first electrode  44  is installed. The first electrode  44  is a metal electrode. The first electrode  44  is made of, for example, Ti/Pt/Au for the light emitting element  40 G and  40 B. The first electrode  44  is made of, for example, AuGe/Ni/Au for the light emitting element  40 R. The first electrode  44  contacts the first conductive layer  41  and is electrically connected to the first conductive layer  41 . In other words, the first electrode  44  makes an ohmic contact with the first conductive layer  41 . The first electrode  44  and the second electrode  45  may be configured as a single electrode together or may be configured as a plurality of electrodes. In addition, hereinafter, as shown in  FIG. 5A , it is assumed that the first electrode  44  and the second electrode  45  are a single electrode together. The first electrode  44  and the second electrode  45  may be configured to include, for example, metal material with high reflectivity such as Ag, Al or the like. 
         [0064]    A side surface S 3  of the mesa portion  40 - 1  is, for example, an inclined surface crossing a lamination direction, as shown in  FIG. 5A , in detail an inclined surface where a cross section of the mesa portion  40 - 1  has an inverse trapezoidal shape. As described above, as the side surface S 3  has a tapered shape, the light emitting efficiency in the front direction may be improved. In addition, the side surface S 3  may be, for example, a vertical surface perpendicular to the lamination direction, as shown in  FIG. 5B . 
         [0065]    As shown in  FIGS. 5A and 5B , each light emitting element  40  has, for example, a laminated body composed of a first insulation layer  46 , a metal layer  47 , and a second insulation layer  48 . The laminated body is a layer formed from the side surface S 3  of the mesa portion  40 - 1  over the surface. The first insulation layer  46 , the metal layer  47  and the second insulation layer  48  are respectively thin layers, for example, formed by a thin film forming process such as CVD, deposition, sputtering or the like. In other words, the first insulation layer  46 , the metal layer  47  and the second insulation layer  48  are not formed by a thick film forming process such as spin coating, resin molding, potting or the like. 
         [0066]    The first insulation layer  46 , the metal layer  47  and the second insulation layer  48  covers at least the entire side surface S 3  to be formed from a region opposite to the side surface S 3  over a part of a region opposite to the first electrode  44 . The first insulation layer  46  is for electric insulation between the metal layer  47  and the semiconductor layer. The first insulation layer  46  is formed, among the side surface S 3 , from the end portion of the mesa portion  40 - 1  at the bottom side over the outer circumference of the surface of the first electrode  44 . In other words, the first insulation layer  46  is formed to contact the entire side surface S 3  and is further formed to contact the outer circumference of the surface of the first electrode  44 . The first insulation layer  46  is made of transparent material with respect to the light generated from the active layer  42 , for example, SiO 2 , SiN, Al 2 O 3 , TiO 2 , TiN or the like. The first insulation layer  46  has, for example, a thickness of about 0.1 μm to 1 μm, substantially regular. In addition, the first insulation layer  46  may have irregularity in thickness due to a production error. 
         [0067]    The metal layer  47  is for covering or reflecting the light generated from the active layer  42 . The metal layer  47  is formed to contact the surface of the first insulation layer  46 . The metal layer  47  is formed, at the surface of the first insulation layer  46 , from the end portion at the light emitting surface S 4  side to a place slightly rearward from the end portion at the first electrode  44  side. In other words, the first insulation layer  46  has an exposed surface  46 A not covered by the metal layer  47 , at a portion opposite to the first electrode  44 . 
         [0068]    The end portion of the metal layer  47  at the light emitting surface S 4  side is formed on the end portion of the first insulation layer  46  at the light emitting surface S 4  side. Meanwhile, the end portion of the metal layer  47  at the first electrode  44  side is formed at a region opposite to the first electrode  44  to partially overlap the metal layer  47  with the first insulation layer  46  being interposed therebetween. In other words, the metal layer  47  is insulated (electrically separated) from the semiconductor layer, the first electrode  44  and the second electrode  45  by the first insulation layer  46 . 
         [0069]    Between the end portion of the metal layer  47  at the first electrode  44  side and the metal layer  47 , a gap (interval) is present as much as the thickness of the first insulation layer  46 . However, since the end portion of the metal layer  47  at the first electrode  44  side and the first electrode  44  overlap each other, the gap (interval) may not be visually recognized in the lamination direction (namely, in the thickness direction). Further, the thickness of the first insulation layer  46  is just several μm at most. Therefore, the light generated from the active layer  42  is substantially not emitted to the outside directly through the gap (interval). 
         [0070]    The metal layer  47  is made of material covering or reflecting the light generated from the active layer  42 , for example, Ti, Al, Cu, Au, Ni, or their alloys. The metal layer  47  has, for example, a thickness of about 0.1 μm to 1 μm, substantially regular. In addition, the metal layer  47  may have irregularity in thickness caused by a production error. 
         [0071]    The second insulation layer  48  is for preventing a conductive material (for example, solder, plate, sputtering metal) joining the pad electrode  52  and a mounting substrate to each other and the metal layer  47  from being shorted, when the light emitting unit  2  is mounted to the mounting substrate (not shown). The second insulation layer  48  is formed to contact the surface of the metal layer  47  and the surface of the first insulation layer  46  (the exposed surface  46 A). The second insulation layer  48  is formed on the entire surface of the metal layer  47  and is formed on all or a part of the exposed surface  46 A of the first insulation layer  46 . In other words, the second insulation layer  48  is formed from the exposed surface  46 A of the first insulation layer  46  over the surface of the metal layer  47  so that the metal layer  47  is covered by the first insulation layer  46  and the second insulation layer  48 . The second insulation layer  48  is made of, for example, SiO 2 , SiN, Al 2 O 3 , TiO 2 , TiN or the like. In addition, the second insulation layer  48  may be made of a plurality of materials among the above materials. The second insulation layer  48  has, for example a thickness of about 0.1 μm to 1 μm, substantially regular. In addition, the second insulation layer  48  may have irregularity in thickness caused by a production error. 
         [0072]    Each light emitting element  40  further includes an embedding layer  49  which covers the mesa portion  40 - 1 , bumps  50  and  51  formed in the embedding layer  49 , and pad electrodes  52  and  53  formed on the embedding layer  49 . The bump  50  is electrically connected to the first electrode  44  so that the surface of the bump  50  is formed, for example, on the same surface as the surface of the embedding layer  49 . The bump  51  is electrically connected to the second electrode  45  so that the surface of the bump  51  is formed in the same surface as the surface of the embedding layer  49 . The pad electrode  52  contacts the bump  50  to be electrically connected to the first electrode  44  through the bump  50 . The pad electrode  53  contacts the bump  51  to be electrically connected to the second electrode  45  through the bump  51 . The bumps  50  and  51  and the pad electrodes  52  and  53 Are electrically separated from the metal layer  47  by the embedding layer  49  and the second insulation layer  48 . 
         [0073]    The embedding layer  49  is made of, for example, resin material such as silicon, acryl, epoxy or the like, or inorganic material such as SiO 2 , SiN, Al 2 O 3 , TiO 2 , TiN or the like. In addition, the embedding layer  49  may be excluded if necessary. The bumps  50  and  51  may be made of, for example, metal material such as Cu, solder or the like. In addition, the bumps  50  and  51  may be excluded if necessary. The pad electrodes  52  and  53  may be made of, for example, metal materials such as Ti, Al, Cu, Au, Ni, or their alloys or the like. In addition, the pad electrodes  52  and  53  may be a plurality of materials among the above materials. 
         [0074]    The pad electrode  52  is an electrode drawn from the first electrode  44  (namely, a drawn electrode). The pad electrode  52  is formed at least at a region opposite to the first electrode  44 , and in detail, is formed at a region which includes a region opposite to the first electrode  44  and a region of the metal layer  47  opposite to the end portion at the first electrode  44  side. In other words, a part of the pad electrode  52  overlaps a part of the metal layer  47  with the embedding layer  49  and the second insulation layer  48  being interposed therebetween. 
         [0075]    Between the end portion of the pad electrode  52  and the metal layer  47 , a gap (interval) is present as much as the thickness of the embedding layer  49  and the second insulation layer  48 . However, since the end portion of the pad electrode  52  and the end portion of the metal layer  47  at the first electrode  44  side overlap each other, the gap (interval) may not be visually recognized in the lamination direction (namely, in the thickness direction). Further, the distance between the end portion of the pad electrode  52  and the metal layer  47  (namely, the thickness of the embedding layer  49  and the second insulation layer  48 ) is just several μm at most. Further, since the end portion of the first electrode  44  and the metal layer  47  at the first electrode  44  side and the end portion of the pad electrode  52  overlap each other, the passage communicating with the outside from the active layer  42  through the first insulation layer  46 , the second insulation layer  48  and the embedding layer  49  is bent in an S shape. In other words, the passage where the light generated from the active layer  42  may pass is curved in as S shape. From the above, the first insulation layer  46 , the second insulation layer  48  and the embedding layer  49  used for insulating the metal layer  47  may be a passage communicating with the outside from the active layer  42 , but this passage may be recognized as being configured so that the light generated from the active layer  42  may substantially not leak out since it is extremely narrow and has an S shape. 
         [0076]    In addition, from the viewpoint that it is prevented for the light generated from the active layer  42  to be directly incident on another light emitting element  40 , the metal layer  47  may not cover a portion of the active layer  42  other than the exposed surface, if it is formed on the surface of the first insulation layer  46  to contact at least a surface of the active layer  42  opposite to the exposed surface. At this time, the first insulation layer  46  may not cover the entire side surface S 3 , if it is formed on the surface of the semiconductor layer to cover at least the exposed surface of the active layer  42 . In addition, the metal layer  47  may not cover the entire side surface S 3 , if it does not cover at least a surface at an adjacent light emitting element  40  side, in the side surface S 3 . At this time, the first insulation layer  46  may not cover the entire side surface S 3  if it does not cover at least a side at an adjacent light emitting element  40  side, in the side surface S 3 . 
         [0077]    In addition, in the case where three light emitting elements  40  included in the light emitting unit  2  are light emitting elements  40 R,  40 G and  40 B, it is preferred that all light emitting elements  40  have the above laminated body, but any light emitting element  40  may not have the above laminated body. For example, among three light emitting elements  40 , the light emitting element  40 B emitting a light of a shortest wavelength may have the above laminated body. In addition, for example, among three light emitting elements  40 , the light emitting element  40 R may have the above laminated body since it emits a light of a longest wavelength. 
         [0078]      FIGS. 6A and 6B  shows an example of a cross-sectional configuration of the light emitting element  40  where the above laminated body is not installed. In addition, in  FIGS. 6A and 6B , the light emitting elements  40  (in detail, the light emitting element  40 G and the light emitting element  40 B) other than the light emitting element  40 R emitting a light of a longest wavelength are exemplified as the light emitting element  40  where the above laminated body is not installed. The light emitting element  40  is, for example, configured so that the metal layer  47  and the second insulation layer  48  are excluded from the above laminated body as shown in  FIGS. 6A and 6B . 
       Insulating Body  50  and Terminal Electrodes  61  and  62   
       [0079]    As shown in  FIG. 4A , the light emitting unit  2  includes a chip-type insulating body  50  covering each light emitting element  40  and terminal electrodes  61  and  62  electrically connected to each light emitting element  40 . The terminal electrodes  61  and  62  are disposed at the bottom surface side of the insulating body  50 . 
         [0080]    The insulating body  50  surrounds and retains each light emitting element  40  at least at the side surface of each light emitting element  40 . The insulating body  50  is made of, for example, resin material such as silicon, acryl, epoxy or the like. The insulating body  50  may include other material such as polyimide or the like in part. The insulating body  50  is formed to contact the side surface of each light emitting element  40  and the surface of each light emitting element  40 . The insulating body  50  has an elongated shape (for example, a rectangular parallelepiped shape) extending in the array direction of each light emitting element  40 . The height of the insulating body  50  is greater than the height of each light emitting element  40 , and the lateral width (the width in the short side direction) of the insulating body  50  is wider than the width of each light emitting element  40 . The size of the insulating body  50  is, for example, 1 mm or less. The insulating body  50  has a thin film shape. The aspect ratio (maximum height/maximum lateral width) of the insulating body  50  is decreasing when the light emitting unit  2  is transcribed so that the light emitting unit  2  does not lie, to be, for example, ⅕ or less. 
         [0081]    As shown in  FIGS. 4A and 4B , the insulating body  50  has, for example, an opening  50 A at a location corresponding to a side just below each light emitting element  40 . At the bottom surface of each opening  50 A, at least the pad electrode  52  (not shown in  FIGS. 4A and 4B ) is exposed. The pad electrode  52  is connected to the terminal electrode  61  through a predetermined conductive member (for example, solder and plated metal). Meanwhile, the pad electrode  53  is connected to the terminal electrode  62  through a predetermined conductive member (for example, solder and plated metal). The terminal electrodes  61  and  62  are configured to mainly include, for example, Cu (copper). A part of the surfaces of the terminal electrodes  61  and  62  may be coated with, for example, material not easily oxidized, such as Au (gold). 
       Effect 
       [0082]    Next, the effects of the light emitting unit  2  of this embodiment will be described. 
         [0083]    In this embodiment, the above laminated body is installed at the light emitting element  40 B emitting a light of a shortest wavelength, among three light emitting elements  40 . By doing so, among the light generated from the active layer  42  in the light emitting element  40  at which the above laminated body is installed, the light propagating toward the inside of the lamination surface may be reflected by the metal layer  47  installed at the side surface of the light emitting element  40  and disturb light incidence to an adjacent light emitting element  40 . As a result, a bad influence (for example, degradation of the resin without a light resistance against a blue light) caused by the light propagating in the insulating body  50  of the light emitting unit  2  may be decreased. In addition, in a case where the above laminated body is installed to at least two light emitting elements  40 B and  40 G among three light emitting elements  40 , the excitation of the light emitting element  40 R caused by the light generated from the light emitting element  40 B or the light emitting element  40 G may also be disturbed. Therefore, the change of color temperature or the range of color reproduction may be reduced. 
         [0084]    In particular, in a case where the first insulation layer  46  and the metal layer  47  cover at least the entire side surface S 3  of the mesa portion  40 - 1 , among the light generated from the active layer  42 , not only the light propagating toward the inside of the lamination surface but also the light propagating in an inclined direction may be reflected to the metal layer  47 . As a result, a bad influence caused by the light propagating in the insulating body  50  of the light emitting unit  2  may be greatly reduced. 
         [0085]    However, since the metal layer  47  installed at the side surface S 3  is electrically separated from the first electrode  44  and the second electrode  45 , there is very little change that the first electrode  44  and the second electrode  45  are shorted through the metal layer  47 . For this reason, there is also very little change that the metal layer  47  installed at the side surface S 3  gives a bad influence on a pressure resistance of the light emitting element  40 . 
         [0086]    However, in this embodiment, in order to avoid that the first electrode  44  and the metal layer  47  are shorted, a gap (interval) is present between the metal layer  47  and the first electrode  44 . However, since the first insulation layer  46  and the metal layer  47  are formed from a region of the mesa portion  40 - 1  opposite to the side surface S 3  over a region opposite to the first electrode  44 , a part of the first electrode  44  and a part of the metal layer  47  overlap each other with the first insulation layer  46  being interposed therebetween. For this reason, the light from the active layer  42  does not directly leak out to the insulating body  50  through the gap (interval) between the first electrode  44  and the metal layer  47 . By doing so, a bad influence caused by the light propagating in the insulating body of the light emitting unit  2  may be reduced without giving a bad influence on the pressure resistance of the light emitting element  40 . 
         [0087]    In addition, in this embodiment, the second insulation layer  48  is formed from the exposed surface  46 A of the first insulation layer  46  over the surface of the metal layer  47 , and further the pad electrode  52  is formed at a region including a region opposite the first electrode  44  and the end portion of the metal layer  47  at the first electrode  44  side. By doing so, since a part of the metal layer  47  and a part of the pad electrode  52  overlap each other with the second insulation layer  48  and the embedding layer  49  being interposed therebetween, there is very little change that the light from the active layer  42  leaks out to the insulating body  50  through the gap (interval) between the first electrode  44  and the metal layer  47 , and between the gap (interval) between the metal layer  47  and the pad electrode  52 . As a result, it is possible to prevent shorting between the metal layer  47  and the first electrode  44  (or, the pad electrode  52 ) more securely and to further reduce the bad influence caused by the light propagating in the insulating body  50  of the light emitting unit  2 . 
       Modification of the Second Embodiment 
       [0088]    In the second embodiment, the first insulation layer  46 , the metal layer  47  and the second insulation layer  48  are mainly formed at the side surface S 3  of the mesa portion  40 - 1  and not installed at the entire side surface of the light emitting element  40 , but it may also be installed at the entire side surface of the light emitting element  40 . For example, as shown in  FIGS. 7A and 7B , the end portions of the first insulation layer  46 , the metal layer  47  and the second insulation layer  48  may be formed at the center of the side surface of the light emitting element  40 , from the end portion at the light emitting surface S 4  side over the outer circumference of the surface of the first electrode  44 . 
         [0089]    In the second embodiment, the embedding layer  49  covering the mesa portion  40 - 1  is installed, but it may be excluded. For example, as shown in  FIGS. 7A and 7B , the embedding layer  49  and the bumps  50  and  51  may be excluded so that the pad electrode  52  directly contacts the first electrode  44  and the pad electrode  53  directly contacts the second electrode  45 . 
       3. Third Embodiment 
     Configuration 
       [0090]    Next, a display device  3 According to a third embodiment of the present disclosure will be described. The display device  3  includes the light emitting unit  1  or the light emitting unit  2  according to the above embodiment as a display pixel.  FIG. 8  is a perspective view showing an example of a general configuration of the display device  3 . The display device  3  is a so-called LED display, and an LED is used as a display pixel. The display device  3  includes, for example, a display panel  310  and a driving circuit (not shown) for driving the display panel  310  as shown in  FIG. 8 . 
       Display Panel  310   
       [0091]    The display panel  310  is configured so that mounting substrates  320  and transparent substrates  330  are put alternately. The surface of the transparent substrate  330  becomes an image display surface to have a display region  3 A at the center portion and have a frame region  3 B, which is a non-display region, around it. 
       Mounting Substrate  320   
       [0092]      FIG. 9  shows an example of a layout of a region of the surface of the mounting substrate  320  at the transparent substrate  330  side, which corresponds to the display region  3 A. In the region of the surface of the mounting substrate  320  which corresponds to the display region  3 A, for example, as shown in  FIG. 9 , a plurality of data wires  321 Are formed to extend in a predetermined direction and is arranged in parallel with a predetermined pitch. In the region of the surface of the mounting substrate  320  which corresponds to the display region  3 A, further for example, a plurality of scan wires  322 Are formed to extend in a direction crossing with (for example, perpendicular to) the data wire  321 And are arranged in parallel with a predetermined pitch. The data wire  321 And the scan wire  322 Are made of, for example, conductive material such as Cu (copper) or the like. 
         [0093]    The scan wire  322  is formed, for example, at the outermost layer, for example on an insulation layer (not shown) formed on the substrate surface. In addition, the base material of the mounting substrate  320  is made of, for example, a glass substrate, a resin substrate or the like, and the insulation layer on the substrate is made of, for example, SiN, SiO 2 , or Al 2 O 3 . Meanwhile, the data wire  321  is formed in a layer other than the outermost layer including the scan wire  322  (for example, a layer below the outermost), and, for example, is formed in the insulation layer on the substrate. On the surface of the insulation layer, in addition to the scan wire  322 , for example, a block is installed as necessary. The block is for enhancing a contrast, and is made of light-absorbing material. The block is formed, for example, at a region of the surface of the insulation layer where pad electrodes  321 B and  322 B, described later, are not formed. In addition, the block may be excluded if necessary. 
         [0094]    A neighborhood of a crossing portion of the data wire  321 And the scan wire  322  becomes a display pixel  323 , and a plurality of display pixels  323  are disposed in the display region  3 A in a matrix shape. At each display pixel  323 , the light emitting unit  1  including a plurality of light emitting elements  40  or the light emitting unit  2  including a plurality of light emitting elements  40  is mounted. In addition,  FIG. 9  exemplarily shows the case where a single display pixel  323  is configured with three light emitting elements  10 R,  10 G and  10 B or three light emitting elements  40 R,  40 G and  40 B so that the light emitting element  10 R or the light emitting element  40 R outputs a light of red color, the light emitting element  10 G or the light emitting element  40 G outputs a light of green color, and the light emitting element  10 B or the light emitting element  40 B outputs a light of blue color, respectively. 
         [0095]    At the light emitting unit  1  and  2 , a pair of terminal electrodes  31  and  32  or a pair of terminal electrode  61  and  62  is installed to each of the light emitting element  10 R,  10 G and  10 B or the light emitting element  40 R,  40 G and  40 B. In addition, one terminal electrode  31  or terminal electrode  61  is electrically connected to the data wire  321 , and the other terminal electrode  32  or terminal electrode  62  is electrically connected to the scan wire  322 . For example, the terminal electrode  31  or the terminal electrode  61  is electrically connected to the pad electrode  321 B of the front end of a branch  321 A installed at the data wire  321 . In addition, for example, the terminal electrode  32  or the terminal electrode  62  is electrically connected to the pad electrode  322 B of the front end of a branch  322 A installed at the scan wire  322 . 
         [0096]    Each pad electrode  321 B and  322 B is formed, for example, at the outermost layer, and, for example, as shown in  FIG. 9 , is installed at a portion where each light emitting unit  1 ,  2  is mounted. Here, the pad electrodes  321 B and  322 B are made of, for example, conductive material such as Au (gold). 
         [0097]    At the mounting substrate  320 , further for example, a plurality of supports (not shown) for regulating a gap between the mounting substrate  320  and the transparent substrate  330  are installed. The support may be installed within a region opposite to the display region  3 A and may be installed within a region opposite to the frame region  3 B. 
       Transparent Substrate  330   
       [0098]    The transparent substrate  330  is made of, for example, a glass substrate, a resin substrate or the like. The surface of the transparent substrate  330  at the light emitting unit  1 ,  2  side may be flat, but is preferably a rough surface. The rough surface may be installed over the entire region opposite to the display region  3 A, or may be installed only in the region opposite to the display pixel  323 . The rough surface has an unevenness as fine as scattering an incident light when the light generated from the light emitting elements  10 R,  10 G and  10 B or the light emitting element  40 R,  40 G and  40 B is incident to the corresponding rough surface. The unevenness of the rough surface may be manufactured by, for example, sand blast, dry etching or the like. 
       Driving Circuit 
       [0099]    The driving circuit drives each display pixel  323  (each light emitting unit  1 ,  2 ) based on an image signal. The driving circuit includes, for example, a data driver for driving the data wire  321  connected to the display pixel  323  and a scan driver for driving the scan wire  322  connected to the display pixel  323 . The driving circuit may be, for example, mounted on the mounting substrate  320 , or may be installed independently from the display panel  310  and connected to the mounting substrate  320  through a wire (not shown). 
       Operation and Effects of the Display Device  3   
       [0100]    In this embodiment, the light emitting unit  1 ,  2  is driven by the driving circuit through the data wire  321  and the scan wire  322  disposed in a simple matrix pattern (simple matrix driving). By doing so, current is supplied to the light emitting unit  1 ,  2  installed near the crossing portion of the data wire  321  and the scan wire  322  one by one so that an image is displayed on the display region  3 A. 
         [0101]    However, in this embodiment, the light emitting unit  1 ,  2  is used as the display pixel  323 . By doing so, a bad influence (for example, degradation of a resin without light resistance against a blue color) caused by the light propagating in the insulating body  20 ,  50  of the light emitting unit  1 ,  2  may be reduced, or the excitation of the light emitting element  10 R,  40 R caused by the light generated from the light emitting element  10 B,  40 B may be prevented. As a result, the change of color temperature or the decrease of a color reproduction range may be reduced, and so it is possible to reduce the aging degradation of the image quality. 
         [0102]    In addition, in this embodiment, in the case where the surface of the transparent substrate  330  is a rough surface, the light generated from the light emitting unit  1 ,  2  in an inclined direction is partly scattered by the rough surface. By doing so, the scattered light is partly emitted out through the transparent substrate  330 , and so it is possible to suppress that the light generated from the light emitting unit  1 ,  2  in an inclined direction is reflected on the rear surface of the transparent substrate  330  or is confined in the transparent substrate  330  to generate stray light. Therefore, the deterioration of light emitting efficiency caused by the transparent substrate  330  may be suppressed. 
         [0103]    Heretofore, the present disclosure has been described based on a plurality of embodiments and their modifications, but the present disclosure is not limited to those embodiments but may be modified in various ways. 
         [0104]    For example, even though the light emitting unit  1 ,  2  has three light emitting elements  10 ,  40  in the above embodiments, it may include only two light emitting elements  10  or four or more light emitting elements  10 ,  40 . 
         [0105]    The present disclosure contains subject matter related to that disclosed in Japanese Priority Patent Application JP 2011-043710 filed in the Japan Patent Office on Mar. 1, 2011, the entire contents of which are hereby incorporated by reference. 
         [0106]    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.

Technology Category: 5