Patent Publication Number: US-9837392-B2

Title: LED lighting apparatus

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a lighting apparatus using a light emitting diode (LED). 
     2. Description of Related Art 
     Various types of LED lighting devices have been conventionally proposed. For example, JP-A-2003-329978 discloses an LED lighting device provided with a plurality of LED chips and a reflector placed behind the LED chips. In this lighting device, the reflector has a plurality of reflecting faces formed to correspond to the plurality of LED chips. 
     In the above lighting device, one corresponding LED chip is placed in front of each reflecting face. For this reason, part of light reflected from the reflecting face is blocked by the LED chip, preventing improvement in the brightness of the lighting device. 
     JP-A-2013-55172 discloses an LED lighting device provided with a plurality of LED chips and a plurality of resin covers each covering the LED chips. The resin covers are formed by dropping a liquid resin material and hardening the material. This technique however causes variations in the shape, height, etc. of the resin covers, preventing improvement in the brightness of the lighting device. 
     SUMMARY OF THE INVENTION 
     The present invention has been proposed under the circumstances described above. It is therefore an objective of the invention to provide an LED lighting apparatus suitable for brightness improvement. 
     An LED lighting apparatus presented according to the first aspect of the invention includes: an LED substrate having a main surface; an LED chip mounted on the main surface of the LED substrate; a sealing resin member made of a material that transmits light from the LED chip, the member covering the LED chip and having a shape of bulging in a direction in which the main surface faces; and a reflecting face surrounding the sealing rein member. 
     An LED lighting apparatus presented according to the second aspect of the invention includes: an LED substrate having a main surface and a reverse surface; a plurality of LED chips mounted on the main surface of the LED substrate; a plurality of sealing resin members covering the plurality of LED chips, each being made of a light-transmissive material and having a shape of bulging in a direction in which the main surface faces; and a plurality of cases supported by the LED substrate. Each of the plurality of cases includes two reflecting faces adjacent as viewed in the thickness direction of the LED substrate, and each of the reflecting faces surrounds one of the plurality of LED chips. 
     Other features and advantages of the invention will become more apparent from the following detailed description taken with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view showing an LED lighting apparatus according to the first embodiment of the invention. 
         FIG. 2  is a front view showing the lighting apparatus of  FIG. 1 . 
         FIG. 3  is a side view showing the lighting apparatus of  FIG. 1 . 
         FIG. 4  is a perspective view showing part of the lighting apparatus of  FIG. 1 . 
         FIG. 5  is a plan view of the part shown in  FIG. 4 . 
         FIG. 6  is a cross-sectional view taken along line VI-VI in  FIG. 5 . 
         FIG. 7  is a cross-sectional view showing part of the lighting apparatus of  FIG. 1 . 
         FIG. 8  is a cross-sectional view taken along line VIII-VIII in  FIG. 5 . 
         FIG. 9  is a plan view showing an auxiliary substrate of the lighting apparatus of  FIG. 1 . 
         FIG. 10  is a bottom view of the auxiliary substrate shown in  FIG. 9 . 
         FIG. 11  is a cross-sectional view showing part of an LED lighting apparatus according to the second embodiment of the invention. 
         FIG. 12  is a cross-sectional view showing a process step of a production method for the lighting apparatus of  FIG. 11 . 
         FIG. 13  is a cross-sectional view showing another process step of the production method. 
         FIG. 14  is a cross-sectional view showing yet another process step of the production method. 
         FIG. 15  is a cross-sectional view showing yet another process step of the production method. 
         FIG. 16  is a cross-sectional view showing part of an LED lighting apparatus according to the third embodiment of the invention. 
         FIG. 17  is a perspective view showing an LED lighting apparatus according to the fourth embodiment of the invention. 
         FIG. 18  is a cross-sectional view taken along line XVIII-XVIII in  FIG. 17 . 
         FIG. 19  is a cross-sectional view showing a process step of a production method for the LED lighting apparatus of  FIG. 17 . 
         FIG. 20  is a cross-sectional view showing another process step of the production method for the LED lighting apparatus of  FIG. 17 . 
         FIG. 21  is a cross-sectional view showing yet another process step of the production method for the LED lighting apparatus of  FIG. 17 . 
         FIG. 22  is a cross-sectional view showing yet another process step of the production method for the LED lighting apparatus of  FIG. 17 . 
         FIG. 23  is a cross-sectional view showing an alteration of the LED lighting apparatus of  FIG. 17 . 
         FIG. 24  is a cross-sectional view showing another alteration of the LED lighting apparatus of  FIG. 17 . 
         FIG. 25  is a cross-sectional view showing an LED lighting apparatus according to the fifth embodiment of the invention. 
         FIG. 26  is a cross-sectional view showing an LED lighting apparatus according to the sixth embodiment of the invention. 
         FIG. 27  is a cross-sectional view showing an LED lighting apparatus according to the seventh embodiment of the invention. 
         FIG. 28  is a plan view showing an LED lighting apparatus according to the eighth embodiment of the invention. 
         FIG. 29  is a front view showing the LED lighting apparatus of  FIG. 28 . 
         FIG. 30  is a side view showing the LED lighting apparatus of  FIG. 28 . 
         FIG. 31  is a perspective view showing part of the LED lighting apparatus of  FIG. 28 . 
         FIG. 32  is a plan view showing part of the LED lighting apparatus of  FIG. 28 . 
         FIG. 33  is a cross-sectional view taken along line XXXIII-XXXIII in  FIG. 32 . 
         FIG. 34  is a cross-sectional view taken along line XXXIV-XXXIV in  FIG. 32 . 
         FIG. 35  is a plan view showing an auxiliary substrate of the LED lighting apparatus of  FIG. 28 . 
         FIG. 36  is a bottom view showing the auxiliary substrate. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Preferred embodiments of the present invention will be specifically described hereinafter with reference to the accompanying drawings. 
       FIGS. 1 to 10  show an LED lighting apparatus according to the first embodiment of the invention. The lighting apparatus A 1  shown includes a substrate (LED substrate)  1 , a plurality of LED chips  2 , a plurality of sealing resin members  3 , a plurality of cases  4 , an auxiliary substrate  5 , and a cover  7 . 
     Lighting apparatuses according to the invention, including the lighting apparatus A 1  of the first embodiment, can be used for various purposes as light sources. For example, the lighting apparatus A 1  can be used as a lighting means for a road traffic information system. 
     The substrate  1  supports a plurality of LED chips  2 . Power supply paths are formed in the substrate  1  for allowing the plurality of LED chips  2  to emit light. The substrate  1  has a main surface  1   a  and a reverse surface  1   b  facing opposite to each other. In  FIG. 2 , the main surface  1   a  faces upward in the z direction, and the reverse surface  1   b  faces downward in the z direction. The plurality of LED chips  2  are mounted on the main surface  1   a . The size of the substrate  1  is about 116 mm in the x direction and about 55 mm in the y direction, for example. The size of the substrate  1  in the z direction (thickness) is in the range of 0.5 mm to 1.5 mm, and it may be about 1.0 mm, for example. 
     As shown in  FIG. 6 , the substrate  1  includes an insulating base  11  and a wiring pattern  12 . The insulating material constituting the base  11  is not specifically limited. In this embodiment, the base  11  is formed of a plurality of layers made of a glass epoxy resin placed on top of one another. The main surface  1   a  of the substrate  1  described above is virtually constituted by the main surface (top surface in  FIG. 7 ) of the base  11 , and the reverse surface  1   b  of the substrate  1  corresponds to the reverse surface of the base  11 . As used herein, therefore, the main surface of the base  11  is denoted by  1   a , and the reverse surface of the base  11  by  1   b.    
     The wiring pattern  12  includes portions formed on the main surface  1   a  of the base  11 , portions formed on the reverse surface  1   b  thereof, and portions formed inside the base  11 . The wiring pattern  12  is made of a metal such as Cu, Pd, Ni, and Au. The wiring pattern  12  may be constituted by a single layer, or of a plurality of layers placed on top of one another. For the wiring pattern  12  constituted by a plurality of layers, the layers may be formed of the same metal or different metals (it is preferable that at least the outermost layer be formed of Au). As shown in  FIGS. 5 to 7 , the wiring pattern  12  includes a plurality of die bonding pads  12   a , a plurality of wire bonding pads  12   b , a plurality of intermediate layers  12   d  and  12   e , and a plurality of through hole portions  12   f.    
     Each die bonding pad  12   a  is a portion to which its corresponding LED chip  2  is die-bonded, and is formed on the main surface  1   a  of the base  11 . In this embodiment, the die bonding pad  12   a  is in a shape of a square having a length of one side of about 1.4 mm. As shown in  FIG. 5 , each wire bonding pad  12   b  is formed to be apart outwardly from its corresponding die bonding pad  12   a  and surround the die bonding pad  12   a . The inner rim of the wire bonding pad  12   b  is similar in shape to the die bonding pad  12   a : it is in a shape of a square having a length of one side of about 1.7 mm, for example. An outer rim  12   c  of the wire bonding pad  12   b  (see  FIG. 7 ) is in a shape of a circle having a diameter of about 2.6 mm, for example. As will be described later, the plurality of die bonding pads  12   a  are arranged such that each die bonding pad is located at an apex of a triangle. The wiring pattern  12  does not include any portion connected to the die bonding pads  12   a  or the wire bonding pads  12   b  on the main surface  1   a.    
     A resist layer  13  is formed on the main surface  1   a . The resist layer  13 , made of an insulating resin, has a plurality of circular openings for exposing the die bonding pads  12   a  and the wire bonding pads  12   b . The diameter of the openings is about 2.9 mm, for example. 
     As shown in  FIG. 7 , the through hole portions  12   f  are connected to the die bonding pads  12   a  and the wire bonding pads  12   b . Each through hole portion  12   f  forms a conducting path extending in the direction of the thickness of the base  11  (z direction). The die bonding pads  12   a  are in conduction with the intermediate layer  12   e  via the through hole portions  12   f . The wire bonding pads  12   b  are in conduction with the intermediate layer  12   d  via their through hole portions  12   f . The intermediate layers  12   d  and  12   f  are formed into predetermined shapes inside the base  11 , forming conducting paths spreading in the xy plane. 
     The plurality of LED chips  2  are die-bonded to the plurality of die bonding pads  12   a  on the main surface  1   a  of the substrate  1 . In this embodiment, as will be understood from  FIGS. 1 and 5 , the LED chips  2  are arranged such that each LED chip is located at an apex of a triangle. The length of one side of the triangle is about 8.0 mm, for example. 
     As shown in  FIG. 7 , each LED chip  2  has a semiconductor layer  20 , an upper electrode  21 , and a lower electrode  22 . The semiconductor layer  20  has a structure of an n-type semiconductor layer, an active layer, and a p-type semiconductor layer placed on top of one another. In this embodiment, the semiconductor layer  20  is made of an AlInGaNp semiconductor and a GaAs semiconductor, for example, and the LED chip  2  emits infrared light. 
     The upper electrode  21  is formed on the top surface of the semiconductor layer  20 . Ends of two wires  25  are bonded to the upper electrode  21 . The other ends of the two wires  25  are bonded to the common wire bonding pad  12   b . These wires  25  extend in the opposite directions from the LED chip  2  as viewed from top. The lower electrode  22  is formed on the bottom surface of the semiconductor layer  20  and joined to the die bonding pad  12   a  with a conductive joining material  26 . 
     The plurality of sealing resin members  3 , each covering one corresponding LED chip  2 , are made of a material that transmits light from the LED chips  2 . As the material of the sealing resin members  3 , a transparent epoxy resin or silicone resin may be used. Each sealing resin member  3  also covers the two wires  25 . The sealing resin member  3  has a shape of bulging in the direction in which the main surface  1   a  faces, i.e., upward in the z direction. 
     The sealing resin member  3  has an. outer rim  3   a . In this embodiment, the outer rim  3   a  coincides with the outer rim  12   c  of the wire bonding pad  12   b . Such a sealing resin member  3  is formed, for example, by dropping a liquid epoxy resin or silicone resin material onto the LED chip  2  via a nozzle, etc. after completion of the die-bonding of the LED chip  2  to the die bonding pad  12   a  and the bonding of the two wires  25 . The dropped liquid resin material covers the LED chip  2  and the two wires  25  and also spreads over the main surface  1   a . By setting the drop amount, etc. properly, the spread of the resin material can be stopped at the outer rim  12   c  of the wire bonding pad  12   b  by the action of surface tension. The resin material is then UV-cured or thermally cured, to obtain the sealing resin member  3  bulging upward in the z direction. 
     The plurality of cases  4  are provided for reflecting part of light emitted from the LED chips  2  upward in the z direction. In this embodiment, each case  4  is formed of a member made of a white polycarbonate resin with A 1  evaporation coating applied thereto. The invention is however not limited to this. For example, if a sufficiently high reflectivity is secured, the case may be formed of only a white resin with no coating applied. Alternatively, the case  4  may be formed of a metal instead of a resin. 
     As shown in  FIGS. 4 to 6 , each case  4  in this embodiment has two reflecting faces  4   a  adjacent to each other. Each reflecting face  4   a  has a ring shape surrounding the corresponding sealing resin member  3 . The reflecting face  4   a  is a concave curved surface, and, in this embodiment, an aspheric surface. The height of the reflecting face  4   a  (size in the z direction) is larger than that of the sealing resin member  3 . As is evident from  FIG. 6 , an inner rim  4   b  of the reflecting face  4   a  is located outside the outer rim  3   a  of the sealing resin member  3  and apart from the outer rim  3   a.    
     As shown in  FIG. 1 , the plurality of cases  4  each having two reflecting faces  4   a  are arranged in correspondence with the plurality of LED chips  2  and the plurality of sealing resin members  3 . As shown in  FIGS. 5 and 8 , two protrusions  41  are formed on each case  4 . The two protrusions  41  are placed between the two reflecting faces  4   a  at positions apart from each other in the direction perpendicular to the direction in which the two reflecting faces  4   a  are apart. The two protrusions  41  do not overlap either of the two reflecting faces  4   a  as viewed in the z direction. 
     Each protrusion  41  engages with a fixing hole  11   a  formed through the substrate  1 , thereby securing the case  4  with respect to the substrate  1 . In this embodiment, the protrusion  41  has a fixed-diameter portion  41   a  and a large-diameter portion  41   b  larger in diameter than the fixed-diameter portion  41   a . The fixed-diameter portion  41   a , constituting a root portion of the protrusion  41 , fits in through the fixing hole  11   a  of the substrate  1 . The large-diameter portion  41   b , constituting a tip portion of the protrusion  41 , expands from the reverse surface  1   b  of the substrate  1 . The large-diameter portion  41   b  is larger in diameter than the diameter of the fixing hole  11   a . With the large-diameter portion  41   b  engaging with the reverse surface  1   b , the protrusion  41  is prevented from coming out of the fixing hole  11   a . Such a large-diameter portion  41   b  can be formed, for example, by forming a rod-shaped portion having a fixed diameter on the case  4 , inserting the rod-shaped portion through the fixing hole  11   a  of the substrate  1 , and then deforming the tip of the rod-shaped portion by heating (heat caulking). In this embodiment, the case  4  is secured to the substrate  1  with only the two protrusions  41 , with no adhesive used. 
     The auxiliary substrate  5  includes a base made of a glass epoxy resin, for example, and a wiring pattern formed on this base, and a plurality of electronic components  51  and two connectors  52  are mounted on the auxiliary substrate  5 .  FIG. 9  is a plan view of the auxiliary substrate  5 , and  FIG. 10  is a bottom view thereof. The auxiliary substrate  5  is placed facing the reverse surface  1   b  of the LED substrate  1  in this embodiment (see  FIG. 2 ), and is in parallel with the LED substrate  1  in this embodiment. The auxiliary substrate  5  and the LED substrate  1  are coupled to each other with four coupling rods  53 . Also, a plurality of conductive rods  54  are attached to the auxiliary substrate  5  and the LED substrate  1 . Each conductive rod  54  includes a conductive member made of a metal, and the conductive member may be covered with an insulating coating. The conductive rod  54  connects an appropriate position of the wiring pattern  12  formed on the reverse surface  1   b  of the LED substrate  1  and an appropriate position of the wiring pattern of the auxiliary substrate  5 . 
     The plurality of electronic components  51  are for activating or lighting up the plurality of LED chips  2 , and include ICs for drive control, chip resistors, and diodes, for example. In this embodiment, the plurality of electronic components  51  also include a plurality of capacitors  51   a . These capacitors  51   a  have a function of storing electric power for allowing the plurality of LED chips  2  to emit light with high brightness simultaneously. As shown in  FIGS. 2, 3, 9, and 10 , part of the plurality of capacitors  51   a  are mounted on the top surface (surface facing the LED substrate  1 ) of the auxiliary substrate  5  while the remainder on the bottom surface thereof. 
     The two connectors  52  are used when the lighting apparatus A 1  is incorporated in a main system (e.g., a traffic information system), and mounted on the bottom surface of the auxiliary substrate  5 . 
     The cover  7  is provided to cover the plurality of sealing resin members  3  and the plurality of cases  4 , and made of a transparent resin, for example. In  FIG. 1 , the cover  7  is represented by the two-dot chain line. The cover  7  has a function of protecting the plurality of sealing resin members  3  and the plurality of cases  4 . Fine prisms may be formed on the surface of the cover  7  to refract light output from the plurality of LED chips  2  in a specific direction. 
     Next, the workings of the lighting apparatus A 1  will be described. 
     In the lighting apparatus A 1 , as shown in  FIG. 6 , light rays, out of the light emitted from each LED chip  2 , travelling upward in the z direction (the direction in which the main surface  1   a  faces) are output upward from the sealing resin member  3 . At this time, with the sealing resin member  3  having a shape of bulging upward in the z direction, the light rays travel in parallel (or roughly in parallel) in the z direction (i.e., the directionality of light is enhanced). As for light rays travelling sideways or obliquely upward from the LED chip  2 , they are reflected by the reflecting face  4   a  after having been output from the sealing resin member  3 . Such light rays therefore travel upward in the z direction. In this way, much of the light emitted from the LED chip  2  can be output in a predetermined direction, and thus improvement in the brightness of the lighting apparatus A 1  can be achieved. 
     According to this embodiment, the outer rim  3   a  of the sealing resin member  3  coincides with the outer rim  12   c  of the wire bonding pad  12   b . This is because the above-described resin material dropped onto the main surface  1   a  for formation of the sealing resin member  3  is dammed up at the outer rim  12   c  of the wire bonding pad  12   b . That is, according to this embodiment, the liquid resin material is prevented from spreading over the main surface  1   a , and thus the sealing resin member  3  can be avoided from taking an inappropriate shape such as a flat shape. The wire bonding pad  12   b  is shaped to completely surround the die bonding pad  12   a , and the outer rim  12   c  thereof is continuous over the entire periphery of the die bonding pad  12   a . This is suitable for finishing of the sealing resin member  3  into a desired shape (e.g., a shape having a smooth curved surface). 
     In this embodiment, since the upper electrode  21  and the wire bonding pad  12   b  are connected with the two wires  25 , a large current can be supplied to the LED chip  2 . This is advantageous for increase in the output of the LED chip  2 , i.e., improvement in the brightness of the lighting apparatus A 1 . Also, with the two wires  25  extending in the opposite directions from the LED chip  2 , the sealing resin member  3  having good shape balance can be formed. 
     In this embodiment, the reflecting face  4   a  is constituted by the case  4  supported by the substrate  1 . Therefore, by simply securing the case  4  to the substrate  1 , the reflecting face  4   a  can be placed at a desired position with respect to the LED chip  2  and the sealing resin member  3 . Moreover, having a ring shape as viewed in the z direction and also having an aspheric shape, the reflecting face  4   a  can reflect light from the LED chip  2  efficiently in the z direction. 
     In this embodiment, the case  4  is made of a resin member subjected to metal coating. Thus, the case  4  can be easily formed into a desired shape and size. Also, with the metal coating, the reflecting face  4   a  having a desired reflectivity can be easily formed. 
     In this embodiment, a plurality of LED chips are mounted on one face of the substrate  1 . Thus, the lighting apparatus A 1  can be provided as a high-brightness light-source device that emits planar light. 
     In this embodiment, a plurality of cases  4  that are not coupled mutually are used. Therefore, even if an individual case  4  is thermally deformed at use, this will not cause undue deformation of the substrate  1 . Also, each case  4  has two reflecting faces  4   a  separately surrounding two adjacent LED chips  2 . Therefore, since the number of cases  4  can be a half of the total number of LED chips  2 , the efficiency of the production process can be enhanced. 
     In this embodiment, the LED chips  2  are arranged such that each LED chip is located at an apex of a triangle. Thus, planar light with a uniform brightness distribution can be output. 
     In this embodiment, the case  4  is secured to the substrate  1  by engaging the protrusions  41  with the fixing holes  11   a  of the substrate  1 . This indicates that most of the bottom surface of the case  4  is in contact with the substrate  1  but not secured thereto. Therefore, for example, even if one of the case  4  and the substrate  1  is thermally deformed, the other is prevented from being affected by this. Also, with the protrusions  41  provided between the two reflecting faces  4   a  adjacent to each other as viewed in the z direction, the case  4  can be secured to the substrate  1  in balance, and increase in the size of the case  4  can be avoided. Moreover, the arrangement of the two protrusions in the direction perpendicular to the direction in which the two adjacent reflecting faces  4   a  are apart is suitable for securing the case  4  in balance. Since the protrusions  41  do not overlap the reflecting faces  4   a  as viewed in the z direction, the reflecting faces  4   a  can be prevented from undue deformation due to heat caulking by which the case  4  is attached to the substrate  1 . 
     In this embodiment, the plurality of LED chips  2  are provided on one surface of the substrate  1 , and the auxiliary substrate  5  is secured to the opposite surface thereof. Therefore, light outgoing from the LED chip  2  will not be blocked by the plurality of electronic components  51 . Also, by placing the auxiliary substrate  5  with an appropriate spacing from the substrate  1 , a desired number of electronic components can be placed on both surfaces of the auxiliary substrate  5 . In particular, since the capacitors  51   a  are needed to allow the plurality of LED chips  2  to emit light with high brightness simultaneously, provision of many capacitors  51   a  contributes to improvement in the brightness of the lighting apparatus A 1 . The placement in this embodiment, in which a number of capacitors  51   a  can be provided on both surfaces of the auxiliary substrate  5 , is therefore advantageous in brightness improvement. 
       FIGS. 11 to 15  show an LED lighting apparatus according to the second embodiment of the invention. In these drawings, the same or similar elements as or to those in the first embodiment described above are denoted by the same reference characters. 
     As shown in  FIG. 11 , in the LED lighting apparatus A 2  of the second embodiment, the configuration of the sealing resin member  3  is different from that in the above embodiment. 
     In the second embodiment, the sealing resin member  3  has a columnar portion  31  and a dome portion  32 . The columnar portion  31  covers the LED chip  2  and has an axial center extending in the z direction. The transverse cross section (perpendicular to the z direction) of the columnar portion  31  is circular, for example. The dome portion  32  is formed on the top surface of the columnar portion  31  and bulges upward in the z direction. 
     The columnar portion  31  and the dome portion  32  may be formed of the same material or different materials. Specifically, both the columnar portion  31  and the dome portion  32  may be formed of a transparent resin (e.g., an epoxy resin or a silicone resin). Alternatively, while the columnar portion  31  being formed of a transparent resin, the dome portion  32  may be formed of a material obtained by mixing a fluorescent material into the transparent resin. The fluorescent material outputs light different in wavelength from the light emitted from the LED chip  2  by being excited by the light from the LED chip  2 . When the LED chip  2  emits blue light, yellow light may be output from the fluorescent material, for example. As a result, white light is finally output from the lighting apparatus A 2 . 
       FIGS. 12 to 15  show an example production method for the lighting apparatus A 2 . 
     First, a plurality of LED chips  2  are mounted on the substrate  1  (in  FIG. 12 , only one LED chip is shown). Two wires  25  are bonded to each LED chip. A sheet S is stuck to the main surface  1   a  of the substrate  1 . The sheet S has a plurality of openings Sa. The openings Sa, formed to correspond to the plurality of LED chips  2 , are each shaped and sized to accommodate one LED chip  2 . The thickness of the sheet S is larger than the height (size in the z direction) of the LED chip  2 . The thickness of the sheet S is also made larger than the distance between the main surface  1   a  and the highest position of the wires in the z direction. The sheet S is formed of a fluorocarbon resin, for example, but may be formed of a material other than this. 
     As shown in  FIG. 13 , each opening Sa in the sheet S is filled with a liquid resin material using a nozzle Nz, for example. The filling amount of the resin material in the opening Sa is an amount with which at least the LED chip  2  and the two wires  25  are completely covered with the resin material, and preferably an amount with which the surface of the resin material is flush with the top surface of the sheet S. The filled liquid resin material is exposed to heat or UV to harden the resin material, thereby obtaining the columnar portion  31  (see  FIG. 11 ). 
     As shown in  FIG. 14 , the sheet S is stripped off from the substrate  1 . As shown in  FIG. 15 , a liquid resin material is dropped onto the top surface of the columnar portion  31  using the nozzle Nz, for example. The drop amount of the resin material at this time is an amount with which the resin material at least covers the entire top surface of the columnar portion  31 , and preferably an amount with which the resin material takes a dome shape. The dropped liquid resin material is exposed to heat or UV to harden the resin material, thereby obtaining the dome portion  32 . Thereafter, the cases  4 , the auxiliary substrate  5 , etc. are attached to the LED substrate  1 , to obtain the lighting apparatus A 2 . 
     Brightness improvement can be achieved also for the lighting apparatus A 2 . In particular, with the dome portion  32  provided on the columnar portion  31 , the distance between the top surface of the sealing resin member  3  and the LED chip  2  can be increased. For sealing resin members  3  whose top surfaces are the same in shape, the directionality will be more enhanced as the distance of the top surface from the LED chip  2  is longer. 
       FIG. 16  shows an LED lighting apparatus according to the third embodiment of the invention. The lighting apparatus A 3  of this embodiment has light guide members  6  in place of the cases  4  in the first and second embodiments described above. In this embodiment, the light guide members  6  are prism lenses, but the invention is not limited to this. 
     The prism lenses  6  are made of a transparent resin (e.g., acrylic), glass, or the like. Each of the prism lenses  6  has a recess portion  61 , an outer side surface  62 , and an outgoing surface  63 . 
     The recess portion  61  opens downward and is closed upward (at the bottom of the recess portion). The prism lens  6  is joined to the substrate  1  with an adhesive at the lower rim of the recess portion  61 . 
     The recess portion  61  houses the sealing resin member  3  inside and has a bottom surface  61   a  and an inner side surface  61   b . The bottom surface  61   a  is located right above the sealing resin member  3  and is larger than the sealing resin member  3  as viewed in the z direction. The bottom surface  61   a  is circular, for example, as viewed in the z direction, and has a shape of bulging downward. With this shape, the bottom surface  61   a  functions as a convex lens. 
     The inner side surface  61   b , connecting the lower rim of the recess portion  61  and the bottom surface  61   a , is cylindrical in this embodiment. The inner side surface  61   b  is parallel to the z direction and located slightly outside the sealing resin member  3  as viewed in the z direction. 
     The outer side surface  62  is a surface extending from the lower end of the prism lens  6  to the upper end thereof. The outer side surface  62  is inclined so that the size of the cross section as viewed in the z direction is larger as the position of the cross section is farther from the substrate  1  in the z direction. Also, the outer side surface  62  a curved surface bulging obliquely downward, and is aspheric in this embodiment. Light travelling laterally from the LED chip  2  passes through the sealing resin member  3  and enters the prism lens  6  at the inner side surface  61   b  thereof. Thereafter, after being totally reflected by the outer side surface  62 , the light travels upward. That is, the outer side surface  62  in this embodiment functions as a reflecting face  6   a.    
     The outgoing surface  63 , connected to the upper end of the outer side surface  62 , is a circular flat surface vertical to the z direction in this embodiment. Light incident on the bottom surface  61   a  of the recess portion  61  or light reflected by the reflecting face  6   a  is output from the outgoing surface  63 . 
     In the lighting apparatus A 3 , light travelling upward from the LED chip  2  is enhanced in directionality by passing through the top surface of the sealing resin member  3  and the bottom surface  61   a  of the prism lens  6 . Also, since the reflecting face  6   a  totally reflects light, the brightness will not be decreased. 
       FIGS. 17 and 18  show an LED lighting apparatus according to the fourth embodiment of the invention. The LED lighting apparatus A 4  of this embodiment includes a substrate (LED substrate)  1 , a plurality of LED chips  2 , and a plurality of sealing resin members  3 . The LED lighting apparatus A 4  is used as a light source device for a dot matrix indicator, for example, but the invention is not limited to this. 
     The substrate  1  supports the plurality of LED chips  2  and also constitutes power supply paths for allowing the LED chips  2  to emit light. The substrate  1  has a main surface  1   a  and a reverse surface  1   b , and includes a base  11  and a wiring pattern  12 . The plurality of LED chips  2  are mounted on the main surface  1   a.    
     The base  11  is made of an insulating material, which is, but not specifically limited to, a glass epoxy resin, for example. In this embodiment, the base  11  is formed of a plurality of layers each made of a glass epoxy resin placed on top of one another. 
     In this embodiment, the wiring pattern  12  is formed on at least the main surface  1   a  of the base  11 , and made of a metal such as Cu, Pd, Ni, and Au. The wiring pattern  12  may be constituted by a single layer, or of a plurality of layers placed on top of one another. For the wiring pattern  12  constituted by a plurality of layers, the layers may be formed of the same metal or different metals (in this embodiment, at least the outermost layer is formed of Au). The wiring pattern  12  includes die bonding pads  12   a  and wire bonding pads  12   b.    
     The LED chips  2  are die-bonded to the die bonding pads  12   a , which are formed on the main surface  1   a . The wire bonding pads  12   b  are formed on the main surface  1   a  and apart from the die bonding pads  12   a.    
     In this embodiment, a drive IC  17  and a connector  18  are provided on the substrate  1 . The drive IC  17  performs control for allowing the plurality of LED chips  2  to emit light. The connector  18  is used for attaching the LED lighting apparatus A 4  to a main system, for example. The connector  18  is in conduction with the wiring pattern  12 . 
     The plurality of LED chips  2  are separately die-bonded to the plurality of die bonding pads  12   a  provided on the main surface  1   a  of the substrate  1 . In this embodiment, the plurality of LED chips  2  are arranged in a matrix. 
     As shown in  FIG. 18 , each of the LED chips  2  includes a semiconductor layer  20 , two upper electrodes  21 , and a sub-mount substrate  24 . The semiconductor layer  20  has a structure of an n-type semiconductor layer, an active layer, and a p-type semiconductor layer placed on top of one another. In this embodiment, the semiconductor layer  20  is formed of GaN semiconductors, and the LED chip  2  emits blue light. 
     The two upper electrodes  21  are formed on the top surface of the semiconductor layer  20 . Ends of two wires  25  are bonded to the two upper electrodes  21 . The other ends of the wires  25  are bonded to the wire bonding pad  12   b . The two wires  25  extend in the opposite directions from the LED chip  2 . The sub-mount substrate  24 , made of Si, for example, supports the semiconductor layer  20 . The sub-mount substrate  24  is secured to the die bonding pad  12   a  with a joining material  27 . 
     Sealing resin members  3  each cover one corresponding LED chip  2 , and are made of a material that transmits light from the LED chip  2 . As the material of the sealing resin members  3 , a transparent resin (e.g., an epoxy resin or a silicone resin) is used, for example. Otherwise, a material obtained by mixing a fluorescent material into the transparent resin may be used. The fluorescent material emits yellow light by being excited by blue light from the LED chip  2 . Having the above configuration, the LED lighting apparatus A 4  finally emits white light. Alternatively, the fluorescent material may be one that emits red light or green light by being excited by blue light. 
     In the LED lighting apparatus A 4  of this embodiment, a plurality of LED chips  2  may be covered with one sealing resin member  3 . It is preferable that such LED chips  2  emit light of different wavelengths from one another, such as red light, blue light, and green light. This will make it possible for the LED lighting apparatus A 4  to output a plurality of kinds of light different in color in each pixel. 
     The sealing resin member  3  includes a columnar portion  31  and a dome portion  32 . The columnar portion  31  is in a shape of a column having an axial center extending in the z direction, and its cross section is circular, for example. The columnar portion  31  is in contact with the main surface  1   a  of the substrate  1 , and covers the LED chip  2  and the two wires  25 . The dome portion  32  is formed on the top surface of the columnar portion  31  and has an upwardly bulging shape. In this embodiment, the dome portion  32  is hemispherical. 
     In this embodiment, the top surface of the columnar portion  31  is not flat but slightly recessed downward. The bottom surface of the dome portion  32  is in close contact with the top surface of the columnar portion  31 . That is, the bottom surface of the dome portion  32  is not flat but slightly protrudes downward. At the interface between the columnar portion  31  and the dome portion  32 , the outer rims of the columnar portion  31  and the dome portion  32  completely coincide with each other. Specifically, the outer rim  31   a  of the top surface of the columnar portion  31  and the outer rim  32   a  of the bottom surface of the dome portion  32  completely coincide with each other. The angle (see angle θ in  FIG. 18 ) formed between the top surface of the columnar portion  31  (or the bottom surface of the dome portion  32 ) and the side surface of the columnar portion  31  is acute (slightly smaller than the right angle in this embodiment). The heights of the columnar portion  31  and the dome portion  32  are each about 1 mm, for example. 
     The surface roughness (e.g., arithmetic mean roughness) of the exposed surface (i.e., side surface) of the columnar portion  31  is larger than that of the exposed surface (i.e., semispherical curved surface) of the dome portion  32 . This difference in surface roughness is caused by the production method for the LED lighting apparatus A 4  (described below). 
       FIGS. 19 to 22  show an example production method for the LED lighting apparatus A 4 . 
     First, a plurality of LED chips  2  are mounted on the substrate  1 , and two wires  25  are bonded to each chip (only one LED chip is shown in  FIG. 19 ). A sheet S is then stuck to the main surface  1   a  of the substrate  1 . The sheet S has a plurality of openings Sa. The openings Sa are each shaped, sized, and positioned to accommodate one corresponding LED chip  2 . As shown in  FIG. 19 , the height of the opening Sa (the thickness of the sheet S) is set so that the LED chip  2  and the two wires  25  are completely housed in the inside of the opening Sa. The sheet S is made of a fluorocarbon resin, for example, but the invention is not limited to this. 
     Thereafter, as shown in  FIG. 20 , each opening Sa of the sheet S is filled with a liquid resin material using a nozzle Nz, etc. The filling amount of the resin material is set to an amount with which at least the LED chip  2  and the two wires  25  are covered with the resin material, and preferably an amount with which the surface of the resin material is in contact with the top end of the sheet S. Note however that, in order to avoid an overflow of the resin material from the opening Sa, an amount with which the surface of the resin material is slightly curved inward as illustrated is preferred. The filled resin material is exposed to heat or UV to harden the resin material, thereby obtaining the columnar portion  31 . 
     Subsequently, as shown in  FIG. 21 , the sheet S is removed from the substrate  1 . The side surface of the columnar portion  31  is constituted by the inner side surface of the opening Sa of the sheet S, and thus the surface roughness of the side surface of the columnar portion  31  depends on the surface roughness of the opening Sa. The opening Sa is formed by punching, for example. Therefore, the inner side surface of the opening Sa is rough compared with a smooth liquid surface formed by surface tension, for example, and the side surface of the columnar portion  31  has similar roughness. 
     Subsequently, as shown in  FIG. 22 , a liquid resin material is dropped onto the top surface of the columnar portion  31  using a nozzle Nz, etc. The drop amount of the resin material at this time is an amount with which the resin material covers at least the entire top surface of the columnar portion  31 , and preferably an amount with which the resin material takes a dome shape. The resin material is exposed to heat or UV to harden the resin material, thereby obtaining the dome portion  32 . The surface of the dome portion  32  is smooth compared with the side surface of the columnar portion  31 . 
     Next, the workings of the LED lighting apparatus A 4  will be described. 
     In the LED lighting apparatus A 4 , with the dome portion  32  provided on the columnar portion  31 , the distance between the top surface of the sealing resin member  3  and the LED chip  2  can be increased. For sealing resin members  3  whose top surfaces are the same in shape, the directionality can be more enhanced as the distance of the top surface from the LED chip  2  is longer. 
     While contributing to increase in the height of the sealing resin member  3 , the columnar portion  31  does not increase the size of the sealing resin member  3  as viewed in the z direction. It is therefore possible to make the LED lighting apparatus A 4  compact while achieving improvement in the brightness of the LED lighting apparatus A 4 . 
     The columnar portion  31  has a size large enough to cover the entire LED chip  2  and the entire wires  25 . Therefore, at the formation of the dome portion  32 , the shape of the dome portion  32  is prevented from becoming deformed due to the LED chip  2  and the wires  25 . 
     The top surface of the columnar portion  31  is not flat but slightly recessed downward. The bottom surface of the dome portion  32  is in close contact with the top surface of the columnar portion  31 . That is, the bottom surface of the dome portion  32  is not flat but slightly protrudes downward. At the interface between the columnar portion  31  and the dome portion  32 , the outer rims of the columnar portion  31  and the dome portion  32  coincide with each other. Specifically, the outer rim  31   a  of the top surface of the columnar portion  31  and the outer rim  32   a  of the bottom surface of the dome portion  32  coincide with each other. The reason is that, as shown in  FIG. 22 , with the outer rim  31   a  of the columnar portion  31 , the dropped resin material is prevented from spreading beyond the outer rim  31   a  at the formation of the dome portion  32 . Using such a technique, the dome portion  32  can be made to bulge in the z direction without fail and also prevented from unduly spreading laterally beyond the columnar portion  31 . 
     Since the angle A (see  FIG. 18 ) formed between the interface between the columnar portion  31  and the dome portion  32  and the side surface of the columnar portion  31  is acute, the resin material can be made to stay on the top surface of the columnar portion  31  by surface tension at the formation of the dome portion  32 . This contributes to formation of the upwardly bulging shape of the dome portion  32 , and eventually to improvement in the brightness of the LED lighting apparatus A 4 . 
       FIGS. 23 and 24  show two alterations of the LED lighting apparatus A 4 . 
     In an LED lighting apparatus A 4 ′ shown in  FIG. 23 , the columnar portion  31  includes the above-described fluorescent material, but the dome portion  32  includes no fluorescent material and is transparent. In contrast to this, in the alteration shown in  FIG. 24 , only the dome portion  32  includes the above-described fluorescent material, and the columnar portion  31  includes no fluorescent material and is transparent. 
     As described above, the sealing resin member  3  may be configured to entirely include a fluorescent material, or partly include it (as in the alterations shown in  FIGS. 23 and 24 ). 
       FIG. 25  shows an LED lighting apparatus according to the fifth embodiment of the invention. The LED lighting apparatus A 5  of this embodiment is different from the above-described embodiments in having a shading layer  8 . The shading layer  8  is joined to the main surface  1   a  of the substrate  1  and has a plurality of openings  8   a  (only one opening is shown in  FIG. 25 ). The opening  8   a  houses the columnar portion  31  of the sealing resin member  3 . 
     Such a shading layer  8  is provided by leaving the sheet S shown in  FIG. 20  behind in its state of being joined to the substrate  1 , for example. In this case, it is preferable that the sheet S be opaque. The dropping of the resin material as shown in  FIG. 22  is performed with the sheet S kept joined to the substrate  1 . 
     In this embodiment, having the shading layer  8 , light leakage from the side surface of the columnar portion  31  is prevented. Also, since the trouble of removing the sheet S used for formation of the columnar portion  31  is saved, the LED lighting apparatus A 5  can be produced efficiently. 
     The shading layer  8  is not limited to the configuration described above. For example, after the process steps shown in  FIGS. 19 to 22 , gaps between any adjacent columnar portions  31  may be filled with an opaque liquid resin (e.g., a white resin), and the resin is then hardened, to form the shading layer  8 . 
       FIG. 26  shows an LED lighting apparatus according to the sixth embodiment of the invention. In the LED lighting apparatus. A 6  of this embodiment, the sealing resin member  3  has a coupling base layer  33 . The coupling base layer  33  covers most of the main surface  1   a  of the substrate  1  and also covers the plurality of LED chips  2 . A groove  33   a  is formed in the coupling base layer  3 . Portions of the coupling base layer  33  separated from one another by the groove  33   a  constitute the plurality of columnar portions  31 . 
       FIG. 27  shows an LED lighting apparatus according to the seventh embodiment of the invention. In the LED lighting apparatus A 7  of this embodiment, a plurality of recess portions  1   c  are formed on the substrate  1  (only one recess portion is formed in  FIG. 27 ). The recess portion  1   c  has a circular cross section and houses the LED chip  2 , the two wires  25 , and the columnar portion  31 . 
     The substrate  1  is obtained in the following manner, for example: the base  11  is formed as a laminated body of a plurality of layers, and the wiring pattern  12  is formed inside the base  11 . An opening is provided through a layer of the base  11  constituting the main surface  1   a , to obtain the recess portion  1   c . The wiring pattern  12  is formed on the top surface of a layer of the base  11  constituting the reverse surface  1   b . As shown in  FIG. 27 , the die bonding pad  12   a  and the wire bonding pad  12   b  are located on the bottom of the recess portion  1   c.    
     The LED chip  2  is die-bonded to the die bonding pad  12   a , and the two wires  25  are bonded to the LED chip  2 . Thereafter, the recess portion  1   c  is filled with a liquid resin material. By hardening the filled resin material, the columnar portion  31  is obtained. A resin material is dropped onto the top surface of the columnar portion  31  and then hardened, to obtain the dome portion  32 . 
       FIGS. 28 to 34  show an LED lighting apparatus according to the eighth embodiment of the invention. The LED lighting apparatus A 8  of this embodiment includes a substrate  1 , a plurality of LED chip  2 , a plurality of sealing resin members  3 , a plurality of cases  4 , an auxiliary substrate  5 , and a cover  7 . 
     The substrate  1  supports the plurality of LED chips  2 , and has power supply paths for allowing the plurality of LED chips  2  to emit light. Specifically, as shown in  FIG. 33 , the substrate  1  has a base  11  and a wiring pattern  12 . The plurality of LED chips  2  are mounted on a main surface  1   a  of the base  11 . 
     The size of the substrate  1  is about 116 mm in the x direction and about 55 mm in the y direction, for example. The size of the substrate  1  in the z direction is 0.5 mm to 1.5 mm, for example: it is about 1.0 mm, for example. 
     The base  11  is made of an insulating material. In this embodiment, the base  11  is a laminated body having a plurality of layers, and each layer is made of a glass epoxy resin, for example. 
     The wiring pattern  12  is formed on the main surface  1   a  and reverse surface  1   b  of the base  11  and inside the base  11 . The wiring pattern  12  may have a single-layer structure made of a metal such as Cu, Pd, Ni, and Au, or have a laminated structure of a plurality of layers. For the wiring pattern  12  having a laminated structure, it is preferable that the surface layer be made of Au. The wiring pattern  12  has a plurality of die bonding pads  12   a  and a plurality of wire bonding pads  12   b  formed on the main surface  1   a  of the base  11 . As will be described later, the die bonding pads  12   a  are arranged such that each die bonding pad is located at an apex of a triangle. 
     A resist layer  13  is formed on the main surface  1   a . The resist layer  13 , made of an insulating resin, has a plurality of circular openings for exposing the die bonding pads  12   a  and the wire bonding pads  12   b . The diameter of the openings is about 2.9 mm, for example. 
     The plurality of LED chips  2  are separately die-bonded to the plurality of die bonding pads  12   a  of the wiring pattern  12  on the main surface  1   a  of the substrate  1 . In this embodiment, as will be understood from  FIG. 28 , the plurality of LED chips  2  are arranged such that each LED chip is located at an apex of a triangle. The length of one side of the triangle is about 8.0 mm, for example. 
     As shown in  FIG. 33 , each LED chip  2  has a semiconductor layer  20 , an upper electrode  21 , and a lower electrode  22 . The semiconductor layer  20  has a structure of an n-type semiconductor layer, an active layer, and a p-type semiconductor layer placed on top of one another. In this embodiment, the semiconductor layer  20  is made of an AlInGaNp semiconductor and a GaAs semiconductor, for example, so that the LED chip  2  emits infrared light. 
     The upper electrode  21  is formed on the top surface of the semiconductor layer  20 . Ends of two wires  25  are bonded to the upper electrode  21 . The other ends of the two wires  25  are bonded to the wire bonding pad  12   b . These wires  25  extend in the opposite directions from the LED chip  2 . The lower electrode  22  is formed on the bottom surface of the semiconductor layer  20  and joined to the die bonding pad  12   a  with a conductive joining material  26 . 
     The plurality of sealing resin members  3 , each covering one corresponding LED chip  2 , are made of a transparent material (e.g., an epoxy resin or a silicone resin) that transmits light from the LED chips  2 . Each sealing resin member  3  also covers the two wires  25 . 
     The cases  4  are provided for reflecting part of light emitted from the LED chips  2  upward in the z direction. In this embodiment, the cases  4  are formed by applying A 1  evaporation coating to a white polycarbonate resin, for example. The invention is however not limited to this. If a sufficient reflectivity is secured, the cases may be formed of only a white resin or only a metal, for example. As shown in  FIGS. 31 to 33 , each case  4  has two reflecting faces  4   a  adjacent to each other. Each reflecting face  4   a  has a ring shape surrounding the corresponding sealing resin member  3 . The reflecting face  4   a  is a concave curved surface, and, in this embodiment, an aspheric surface. As shown in  FIG. 33 , the reflecting face  4   a  is larger in height than the sealing resin member  3 . 
     As shown in  FIG. 28 , the plurality of cases  4  are arranged to correspond to the plurality of sealing resin members  3  (eventually to the plurality of LED chips  2 ). As shown in  FIGS. 32 and 34 , two protrusions  41  are formed in each case  4 . The two protrusions  41  are placed between the two reflecting faces  4   a  at positions apart from each other in the direction perpendicular to the direction in which the two reflecting faces  4   a  are apart. The two protrusions  41  do not overlap either of the two reflecting faces  4   a  as viewed in the z direction. 
     As shown in  FIG. 34 , each protrusion  41  engages with a fixing hole  11   a  formed through the substrate  1 , whereby the case  4  is secured with respect to the substrate  1 . In this embodiment, the protrusion  41  has a fixed-diameter portion  41   a  and a large-diameter portion  41   b . The fixed-diameter portion  41   a  fits in through the fixing hole  11   a  of the substrate  1 . The large-diameter portion  41   b , constituting a tip portion of the protrusion  41 , expands from the reverse surface  1   b  of the substrate  11 . The large-diameter portion  41   b  is larger in diameter than the fixing hole  11   a , thereby preventing the protrusion  41  from coming out of the fixing hole  11   a . Such a large-diameter portion  41   b  can be formed by forming a rod-shaped portion having a fixed diameter on the case  4 , inserting the rod-shaped portion through the fixing hole  11   a  of the substrate  1 , and then deforming the tip of the rod-shaped portion by heating, i.e., heat caulking, for example. In this embodiment, the case  4  is secured to the substrate  1  with the two protrusions  41 , with no adhesive used. 
     The auxiliary substrate  5  includes a base (made of a glass epoxy resin, for example) and a wiring pattern formed on this base. A plurality of electronic components and two connectors  52  are mounted on the auxiliary substrate  5 .  FIG. 35  is a plan view of the auxiliary substrate  5 , and  FIG. 36  is a bottom view thereof. As shown in  FIG. 29 , the auxiliary substrate  5  is placed apart from the substrate  1  to face the reverse surface  1   b  of the substrate  1 . In this embodiment, the auxiliary substrate  5  is in parallel with the substrate  1 . The auxiliary substrate  5  and the substrate  1  are coupled to each other with four coupling rods  53 . Also, a plurality of conductive rods  54  are attached to the auxiliary substrate  5  and the substrate  1 . Each conductive rod  54  includes a conductive member made of a metal, and the conductive member is covered with an insulating coating, for example. The conductive rod  54  is connected to an appropriate position of the wiring pattern  12  of the substrate  1  and an appropriate position of the wiring pattern of the auxiliary substrate  5 . 
     The plurality of electronic components  51  are for lighting up the plurality of LED chips  2 , and include ICs for drive control, chip resistors, and diodes, for example. In this embodiment, the plurality of electronic components include a plurality of capacitors  51   a . These capacitors  51   a  have a function of storing electric power for allowing the plurality of LED chips  2  to emit light with high brightness simultaneously. As shown in  FIGS. 29, 30, 35, and 36 , part of the plurality of capacitors  51   a  are mounted on one surface of the auxiliary substrate  5  while the remainder of the capacitors  51   a  on the other surface thereof. 
     The two connectors  52  are used when the LED lighting apparatus A 8  is incorporated in a traffic information system, for example. As shown in  FIGS. 29 and 36 , the two connectors  52  are mounted on one surface (surface opposite from the substrate  1 ) of the auxiliary substrate  5 . 
     The cover  7 , made of a transparent resin, for example, is provided to cover the plurality of sealing resin members  3  and the plurality of cases  4 . In  FIG. 28 , the cover  7  is represented by the two-dot chain line. The cover  7  has a function of protecting the plurality of sealing resin members  3  and the plurality of cases  4 . The surface of the cover  7  may be machined (e.g., fine prisms may be formed) to refract light emitted from the plurality of LED chips  2  in a specific direction. 
     As shown in  FIG. 33 , part of the light emitted from the LED chip  2  is output upward through the dome portion  32  of the sealing resin member  3 . At this time, with the upwardly bulging dome portion  32 , the directionality of the output light is enhanced so that the light travel in the z direction. The other part of the light emitted from the LED chip  2  is reflected by the reflecting face  4   a  after having been output from the columnar portion  31  of the sealing resin member  3 , whereby the light travels upward in the z direction. In this way, most of the light emitted from the LED chip  2  can be directed toward the object to be illuminated. 
     The upper electrode  21  and the wire bonding pad  12   b  are connected by the two wires  25 . Therefore, a large current can be supplied to the LED chip  2 , and this contributes to improvement in the brightness of the LED lighting apparatus A 8 . Also, with the two wires  25  extending in the opposite directions from the LED chip  2 , deterioration in the shape of the sealing resin member  3  can be avoided. 
     The reflecting face  4   a  has a ring shape as viewed in the z direction and also has an aspheric shape. Therefore, the reflecting face  4   a  can reflect light from the LED chip  2  efficiently in the z direction. 
     The case  4  is made of a resin member subjected to metal coating. The resin member can be easily formed into a desired shape and size. The metal coating contributes to enhancement in the reflectivity of the reflecting face  4   a.    
     With a plurality of LED chips  2  mounted on the substrate  1 , a high-brightness light source device emitting planar light can be provided. With a plurality of cases  4  spaced from one another, even if an individual case  4  is thermally deformed at use, the substrate  1  can be prevented from being unduly deformed. 
     Since the plurality of LED chips  2  are arranged such that each LED chip is located at an apex of a triangle, planar light with a uniform brightness distribution can be output. 
     The case  4  is secured to the substrate  1  with the protrusions  41  engaging with the fixing holes  11   a  of the substrate  1 . Therefore, the case  4  can be secured to the substrate  1  without fail. Also, at the time of thermal deformation, it is possible to prevent or reduce such an occurrence that the case  4  and the substrate  1  may affect each other. 
     With the two protrusions  41  located between the two adjacent reflecting faces  4   a , the case  4  can be secured to the substrate  1  in balance. Also, with the provision of the protrusions  41 , the case  4  can be avoided from increasing in size. Since the protrusions  41  do not overlap the reflecting faces  4   a  as viewed in the z direction, the reflecting faces  4   a  can be prevented from undue deformation in the process of heat caulking for attaching the case  4  to the substrate  1 . 
     With the auxiliary substrate  5  provided on the side of the substrate  1  opposite to the side on which the plurality of LED chips  2  are provided, a plurality of electronic components  51  can be placed without blocking output of light. Also, since the auxiliary substrate  5  is apart from the substrate  1 , a plurality of electronic components  51  can be provided on both surfaces of the auxiliary substrate  5 . The capacitors  51   a  has a function of storing electric power required for allowing the plurality of LED chips  2  to emit light with high brightness simultaneously. Therefore, providing a larger number of capacitors  51   a  is suitable for improvement in the brightness of the LED lighting apparatus A 8 . The placement in this embodiment, in which a number of capacitors  51   a  are provided on both surfaces of the auxiliary substrate  5 , is therefore advantageous in brightness improvement. 
     The LED lighting apparatuses according to the invention are not limited to the embodiments described above, and the specific configurations of the components of the devices can be freely changed in design in various ways. 
     As described above, a plurality of LED chips may be covered with one sealing resin member. Such a plurality of LED chips may be three LED chips emitting red light, green light, and blue light, for example. The LED chips may be of a flip chip type using no connection wire. 
     Variations of the present invention will be listed as follows as supplementary appendixes. 
     [Appendix 1] 
     An LED lighting apparatus including: 
     an LED substrate having a main surface; 
     an LED chip provided on the main surface of the LED substrate; and 
     a sealing resin member made of a material that transmits light from the LED chip, the member covering the LED chip, 
     wherein the sealing resin member includes a columnar portion that is in contact with the main surface and a dome portion that is formed on the columnar portion and bulges in a direction in which the main surface faces. 
     [Appendix 2] 
     The LED lighting apparatus of appendix 1, wherein the columnar portion covers the entirety of the LED chip. 
     [Appendix 3] 
     The LED lighting apparatus of appendix 2, further including a wire bonded to the LED chip, wherein 
     the columnar portion covers the entirety of the wire. 
     [Appendix 4] 
     The LED lighting apparatus of appendix 1, wherein the columnar portion is circular in cross section. 
     [Appendix 5] 
     The LED lighting apparatus of appendix 1, wherein the columnar portion and the dome portion respectively have a top surface and a bottom surface that are in contact with each other, and an outer rim of the top surface and an outer rim of the bottom surface coincide with each other. 
     [Appendix 6] 
     The LED lighting apparatus of appendix 5, wherein the angle formed between the top surface of the columnar portion and the side surface of the columnar portion is acute. 
     [Appendix 7] 
     The LED lighting apparatus of appendix 1, wherein the surface roughness of the columnar portion is larger than the surface roughness of the dome portion. 
     [Appendix 8] 
     The LED lighting apparatus of appendix 1, wherein the sealing resin member includes a fluorescent material, and, by being excited by light from the LED chip, the fluorescent material emits light different in wavelength from the light from the LED chip. 
     [Appendix 9] 
     The LED lighting apparatus of appendix 8, wherein only the columnar portion includes the fluorescent material. 
     [Appendix 10] 
     The LED lighting apparatus of appendix 8, wherein only the dome portion includes the fluorescent material. 
     [Appendix 11] 
     The LED lighting apparatus of appendix 1, further comprising a shading layer supported by the main surface of the LED substrate, wherein the shading layer surrounds the columnar portion and also shades light from the LED chip. 
     [Appendix 12] 
     The LED lighting apparatus of appendix 11, wherein the shading layer is made of a resin sheet joined to the main surface. 
     [Appendix 13] 
     The LED lighting apparatus of appendix 11, wherein the shading layer is made of a resin fed to fill a portion surrounding the columnar portion. 
     [Appendix 14] 
     The LED lighting apparatus of appendix 1, wherein the substrate has a recess portion recessed from the main surface, and the columnar portion is housed in the recess portion. 
     [Appendix 15] 
     The LED lighting apparatus of appendix 1, further including a reflecting face surrounding the sealing resin member. 
     [Appendix 16] 
     The LED lighting apparatus of appendix 15, further including a case supported by the LED substrate, and the reflecting face is constituted by the case. 
     [Appendix 17] 
     The LED lighting apparatus of appendix 16, wherein the reflecting face has a ring shape as viewed in the thickness direction of the LED substrate and has an aspheric shape. 
     [Appendix 18] 
     The LED lighting apparatus of appendix 16, wherein the case includes a resin member and a metal coating formed on the resin member. 
     [Appendix 19] 
     The LED lighting apparatus of appendix 1, further including an auxiliary substrate and a plurality of electronic components provided on the auxiliary substrate, 
     wherein the auxiliary substrate is apart from the LED substrate, and the plurality of electronic components are provided for activating the LED chip. 
     [Appendix 20] 
     The LED lighting apparatus of appendix 19, wherein the auxiliary substrate is in parallel with the LED substrate. 
     [Appendix 21] 
     The LED lighting apparatus of appendix 19, wherein the plurality of electronic components are mounted on two surfaces of the auxiliary substrate. 
     [Appendix 22] 
     The LED lighting apparatus of appendix 19, wherein the plurality of electronic components include a capacitor. 
     [Appendix 23] 
     The LED lighting apparatus of appendix 19, further including a connector, wherein the auxiliary substrate has a surface facing the LED substrate and a reverse surface opposite to the surface, and the connector is mounted on the reverse surface of the auxiliary substrate. 
     [Appendix 24] 
     An LED lighting apparatus including: 
     an LED substrate having a main surface and a reverse surface; 
     a plurality of LED chips provided on the main surface of the LED substrate; 
     a plurality of light-transmissive sealing resin members covering the plurality of LED chips; and 
     a plurality of cases provided on the main surface of the LED substrate, 
     wherein each of the plurality of sealing resin members includes a columnar portion that is in contact with the main surface and a dome portion that is formed on the columnar portion and bulges in a direction in which the main surface faces, and 
     each of the plurality of cases includes two reflecting faces, and each of the reflecting faces surrounds one of the plurality of LED chips. 
     [Appendix 25] 
     The LED lighting apparatus of appendix 24, wherein each of the plurality of LED chips is located at an apex of a triangle. 
     [Appendix 26] 
     The LED lighting apparatus of appendix 24, wherein a plurality of fixing holes are formed through the LED substrate, and 
     each of the cases includes a fixed-diameter portion and a large-diameter portion larger in size than the fixed-diameter portion, the fixed-diameter portion sits inside one of the plurality of fixing holes, and the large-diameter portion engages with the reverse surface of the LED substrate. 
     [Appendix 27] 
     A production method for an LED lighting apparatus, including the steps of: 
     preparing an LED substrate having a main surface on which an LED chip is mounted; 
     joining a sheet having an opening to the LED substrate so that the opening can house the LED chip inside; 
     filling the opening with a first resin material; 
     hardening the first resin material to form a columnar portion having a surface facing in the same direction as that in which the main surface faces; 
     dropping a second resin material onto the surface of the columnar portion; and 
     hardening the second resin material to form a dome portion. 
     [Appendix 28] 
     The production method for an LED lighting apparatus of appendix 27, further including the step of removing the sheet from the LED substrate after the step of hardening the first resin material and before the step of dropping the second resin material.