Abstract:
An object is to provide an LED module that eliminates the need for providing electrodes between each device and allows LEDs to be arrayed with high density. An LED module includes a substrate, a first frame member, a second frame member disposed outside the first frame member, a plurality of LEDs for producing white light disposed within the first frame member, a phosphor resin disposed within the first frame member, a plurality of LEDs for producing colored light disposed between the first frame member and the second frame member, and electrodes for applying a voltage to the plurality of LEDs for producing the white light, wherein a metal wire to connect the plurality of LEDs for producing the colored light to one another is disposed so as to straddle a part of each of the electrodes.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a new U.S. patent application that claims benefit of JP 2014-152381, filed on Jul. 25, 2014, the entire content of JP 2014-152381 is hereby incorporated by reference. 
       TECHNICAL FILED 
       [0002]    The present invention relates to an LED module, and more specifically relates to an LED module that can emit white light and light of full colors by itself. 
       BACKGROUND OF THE INVENTION 
       [0003]    LEDs, i.e., semiconductor devices that are compact in size and emit light of bright colors with high luminous efficiency, as well as having a long life and high drive performance, are becoming widely used in recent years for lighting and the like. 
         [0004]    An LED module is known in which blue LEDs and a phosphor resin layer to emit yellow light of 3500K are disposed inside, and blue LEDs and a phosphor resin layer to emit white light of 6500K are disposed outside. The LED module mixes the yellow light and the white light (see Japanese Patent Application Laid-Open No. 2011-49516, for example). 
       SUMMARY OF THE INVENTION 
       [0005]    However, since the LEDs are bonded separately to respective electrodes with wire, the electrodes are each required to be disposed between the devices. Furthermore, the electrodes, each disposed between the devices, hinder the LEDs from being arrayed with high density. 
         [0006]    An object of the present invention is to provide an LED module that can solve the problems described above. 
         [0007]    Another object of the present invention is to provide an LED module that can eliminate the need for providing the electrodes between each device and allow LEDs to be arrayed with high density. 
         [0008]    Yet another object of the present invention is to provide an LED module that can emit white light and light of full colors, while eliminating the need for providing the electrodes between each device and allowing LEDs to be arrayed with high density. 
         [0009]    An LED module includes a substrate, a first frame member, a second frame member disposed outside the first frame member, a plurality of LEDs for producing white light disposed within the first frame member and on the substrate, a phosphor resin disposed within the first frame member to protect the plurality of LEDs for producing white light, a plurality of LEDs for producing colored light disposed between the first frame member and the second frame member and on the substrate, and electrodes for applying a voltage to the plurality of LEDs for producing white light, wherein a part of each of the electrodes is disposed between the first frame member and the second frame member, and wherein metal wire for connecting the plurality of LEDs for producing the colored light to one another is disposed in such a manner as to straddle the parts of the electrodes disposed between the first frame member and the second frame member. 
         [0010]    In the above LED module, it is preferable that the plurality of LEDs for producing colored light include red LEDs, green LEDs, and blue LEDs, that the LED module further include red electrodes for applying a voltage to the red LEDs, green electrodes for applying a voltage to the green LEDs, and blue electrodes for applying a voltage to the blue LEDs, and that a red metal wire for connecting the red LEDs to one another be disposed in such a manner as to straddle the green electrodes and the blue electrodes. 
         [0011]    In the above LED module, the red metal wire is preferably disposed in such a manner as to straddle the green electrodes and the blue electrodes via metal bumps. 
         [0012]    In the above LED module, a resist resin for protection is preferably disposed between the red metal wire and the green electrode and between the red metal wire and the blue electrode. 
         [0013]    In the above LED module, it is preferable that the first frame member and the second frame member be concentrically disposed on the substrate. 
         [0014]    In the above LED module, it is preferable that another part of each of the electrodes for applying the voltage to the plurality of LEDs for producing the white light be disposed under the first frame member, and the plurality of LEDs for producing the white light be connected to the parts of the electrodes disposed under the first frame member by metal wire. 
         [0015]    According to the LED module described above, the two frame members form the inner and outer mounting areas, and the electrodes for applying the voltage to the LEDs disposed in the inner mounting area are disposed under the inner frame member, thus eliminating the need for providing other electrodes between each device. Therefore, the LEDs can be arrayed with high density in the above LED module. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    Other features and advantages of the present invention will be better understood based on the following detailed description, taken together with the drawings wherein: 
           [0017]      FIG. 1A  is a top plan view of an LED module  1  according to the present invention. 
           [0018]      FIG. 1B  is a cross-sectional view taken along the line AA′ in  FIG. 1A . 
           [0019]      FIG. 2  is a drawing for explaining electrodes for blue LEDs for producing white light arrayed in a first mounting area  2 . 
           [0020]      FIG. 3  is a drawing for explaining electrodes for green LEDs arrayed in second to fifth mounting areas  3 - 1  to  3 - 4 . 
           [0021]      FIG. 4  is a drawing for explaining electrodes for red LEDs arrayed in the second to fifth mounting areas  3 - 1  to  3 - 4 . 
           [0022]      FIG. 5  is a drawing for explaining electrodes for blue LEDs arrayed in the second to fifth mounting areas  3 - 1  to  3 - 4 . 
           [0023]      FIG. 6A  is an enlarged view of a portion B shown in  FIG. 1A . 
           [0024]      FIG. 6B  is an enlarged view of a portion C shown in  FIG. 1B . 
       
    
    
     DESCRIPTION 
       [0025]    An LED module according to the present invention will be described below with reference to the drawings. It is noted that the technical scope of the present invention is not limited to the embodiments thereof, but extends to the invention described in the claims and equivalents thereof. 
         [0026]      FIG. 1A  is the top plan view of an LED module  1  according to the present invention, and  FIG. 1B  is the cross-sectional view taken along the line AA′ in  FIG. 1A . 
         [0027]    The LED module  1  is constituted of an aluminum substrate  10 , various electrodes, a first frame member  11 , a second frame member  12 , LEDs of various colors, a phosphor resin  16 , and the like. The LED module  1  is attached to a lighting fixture or the like using guide holes  13  provided at its end portions. 
         [0028]    As shown in  FIG. 1A , the first frame member  11  and the second frame member  12  are concentrically disposed. A first mounting area  2  is provided within the first frame member  11 . Second to fifth mounting areas  3 - 1  to  3 - 4  are provided outside the first frame member  11  and between the first frame member  11  and the second frame member  12 . Each mounting area is an area provided on the aluminum substrate  10 , to mount the LEDs of individual colors. In the mounting areas, the LEDs of individual colors are bonded directly onto the aluminum substrate  10  with a die bond. 
         [0029]    First wiring areas  4 - 1  and  4 - 2  are provided between the fifth mounting area  3 - 4  and the second mounting area  3 - 1 , and between the third mounting area  3 - 2  and the fourth mounting area  3 - 3 , respectively. Second wiring areas  5 - 1  and  5 - 2  are provided between the second mounting area  3 - 1  and the third mounting area  3 - 2 , and between the fourth mounting area  3 - 3  and the fifth mounting area  3 - 4 , respectively. 
         [0030]    In the first mounting area  2 , a plurality of blue LEDs  25  for producing white light are arrayed. The plurality of blue LEDs  25  are bonded directly onto the aluminum substrate  10  with the die bond. 
         [0031]    The inside of the first frame member  11  is filled with the phosphor resin  16  to protect the blue LEDs  25 . As the phosphor resin  16 , a translucent epoxy resin or silicone resin is usable. The phosphor resin  16  contains a phosphor mixed in the resin. The phosphor absorbs a part of blue light emitted from the blue LEDs  25  and emits yellow light produced by wavelength conversion of the blue light, so that white light is emitted from the inside of the first frame member  11  as a mixture of the blue light and the yellow light. Note that, the phosphor resin  16  may contain a diffusing material to uniformly diffuse the light emitted from the blue LEDs  25 . 
         [0032]    A plurality of green LEDs  35 , a plurality of red LEDs  45 , and a plurality of blue LEDs  55  for producing colored light are arrayed in the second to fifth mounting areas  3 - 1  to  3 - 4 . The plurality of green LEDs  35 , the plurality of red LEDs  45 , and the plurality of blue LEDs  55  are bonded directly onto the aluminum substrate  10  with the die bond. 
         [0033]    A protective layer  70  is formed between the first frame member  11  and the second frame member  12  to protect the plurality of green LEDs  35 , the plurality of red LEDs  45 , and the plurality of blue LEDs  55 . As the protective layer  70 , a translucent epoxy resin or silicone resin is usable. Monochromatic light of each individual color by each of the plurality of green LEDs  35 , the plurality of red LEDs  45 , and the plurality of blue LEDs  55 , and colored light, i.e., a mixture of the monochromatic light can be emitted from the second to fifth mounting areas  3 - 1  to  3 - 4 . 
         [0034]    An anode electrode  20  and a cathode electrode  21  are disposed outside the second frame member  12  to apply a voltage to the blue LEDs  25  arrayed in the first mounting area  2 . An anode electrode  30  and a cathode electrode  31  are also disposed outside the second frame member  12  to apply a voltage to the green LEDs  35  arrayed in the second to fifth mounting areas  3 - 1  to  3 - 4 . An anode electrode  40  and a cathode electrode  41  are also disposed outside the second frame member  12  to apply a voltage to the red LEDs  45  arrayed in the second to fifth mounting areas  3 - 1  to  3 - 4 . Furthermore, an anode electrode  50  and a cathode electrode  51  are disposed outside the second frame member  12  to apply a voltage to the blue LEDs  55  arrayed in the second to fifth mounting areas  3 - 1  to  3 - 4 . 
         [0035]    A resist layer  17  is applied to the circumference of the second frame member  12  except the portions of the anode electrodes and the cathode electrodes for the LEDs of individual colors. In the LED module  1 , the control for the white light and the colored light can be performed independently by applying different voltages to each pair of the anode and cathode electrodes for the LEDs of each individual color. 
         [0036]      FIG. 2  is the drawing that explains electrodes for the blue LEDs for producing the white light arrayed in the first mounting area  2 . 
         [0037]    The anode electrode  20  is connected to an electrode  22  that passes through the first wiring area  4 - 1  and is disposed along the first mounting area  2  under the first frame member  11 . The cathode electrode  21  is connected to an electrode  23  that passes through the first wiring area  4 - 2  and is disposed under the first frame member  11  so as to be opposite to the electrode  22  across the first mounting area  2 . The blue LEDs  25  for producing the white light are divided into eleven groups each of which includes fifteen of the blue LEDs  25  connected in series by metal wire  26 . The eleven groups of the fifteen blue LEDs  25  for producing the white light are connected in parallel between the electrodes  22  and  23 . All of the blue LEDs  25  for producing the white light are turned on by applying a voltage of 15×Vfw (a forward voltage of the blue LED for producing the white light) or more between the anode electrode  20  and the cathode electrode  21 . 
         [0038]    Since the electrodes  22  and  23  to apply the voltage to the blue LEDs  25  for producing the white light are disposed under the first frame member  11 , it is possible to eliminate the need for providing other electrodes for use in wire bonding to the respective blue LEDs  25  for producing the white light. Therefore, the blue LEDs  25  for producing the white light can be arrayed within the first mounting area  2  with high density. 
         [0039]      FIG. 3  is the drawing that explains electrodes for the green LEDs arrayed in the second to fifth mounting areas  3 - 1  to  3 - 4 . 
         [0040]    The anode electrode  30  is connected to an electrode  32  disposed along the second mounting area  3 - 1 , and the cathode electrode  31  is connected to an electrode  33  disposed along the fourth and fifth mounting areas  3 - 3  and  3 - 4 . The electrode  32  includes a narrow electrode  32 - 1  disposed in the second wiring area  5 - 1 . Similarly, the electrode  33  includes a narrow electrode  33 - 1  disposed in the second wiring area  5 - 2 . 
         [0041]    The green LEDs  35  are divided into eight groups each of which includes twenty-four of the green LEDs  35  connected in series by metal wire  36 . The eight groups of the twenty-four green LEDs  35  are connected in parallel between the narrow electrodes  32 - 1  and  33 - 1 . All the green LEDs  35  are turned on by applying a voltage of 24×Vfg (a forward voltage of the green LED) or more between the anode electrode  30  and the cathode electrode  31 . 
         [0042]      FIG. 4  is the drawing that explains electrodes for the red LEDs arrayed in the second to fifth mounting areas  3 - 1  to  3 - 4 . 
         [0043]    The anode electrode  40  is connected to an electrode  42  disposed along the second mounting area  3 - 1 , and the cathode electrode  41  is connected to an electrode  43  disposed along the fourth mounting area  3 - 3 . The electrode  42  includes a narrow electrode  42 - 1  disposed in the second wiring area  5 - 1 . Similarly, the electrode  43  includes a narrow electrode  43 - 1  disposed in the second wiring area  5 - 2 . 
         [0044]    The red LEDs  45  are divided into four groups each of which includes twenty-four of the red LEDs  45  connected in series by metal wire  46 . The four groups of the twenty-four red LEDs  45  are connected in parallel between the narrow electrodes  42 - 1  and  43 - 1 . All the red LEDs  45  are turned on by applying a voltage of 24×Vfr (a forward voltage of the red LED) or more between the anode electrode  40  and the cathode electrode  41 . 
         [0045]      FIG. 5  is the drawing that explains electrodes for the blue LEDs arrayed in the second to fifth mounting areas  3 - 1  to  3 - 4 . 
         [0046]    The anode electrode  50  is connected to an electrode  52  disposed along the second and third mounting areas  3 - 1  and  3 - 2 , and the cathode electrode  51  is connected to an electrode  53  disposed along the fourth mounting area  3 - 3 . The electrode  52  includes a narrow electrode  52 - 1  disposed in the second wiring area  5 - 1 . Similarly, the electrode  53  includes a narrow electrode  53 - 1  disposed in the second wiring area  5 - 2 . 
         [0047]    The blue LEDs  55  are divided into four groups each of which includes twenty-four of the blue LEDs  55  connected in series by metal wire  56 . The four groups of the twenty-four blue LEDs  55  are connected in parallel between the narrow electrodes  52 - 1  and  53 - 1 . All of the blue LEDs  55  are turned on by applying a voltage of 24×Vfb (a forward voltage of the blue LED) or more between the anode electrode  50  and the cathode electrode  51 . 
         [0048]      FIG. 6A  is the enlarged view of the portion B shown in  FIG. 1A .  FIG. 6B  is the enlarged view of the portion C shown in  FIG. 1A . 
         [0049]      FIG. 6A  shows the connection state of the red LEDs  45  shown in  FIG. 4  to the narrow electrode  43 - 1  in the second wiring area  5 - 2 . In the second wiring area  5 - 2 , the left and right red LEDs  45  are each connected to the narrow electrode  43 - 1  by bent metal wire  47  in such a manner as to straddle the narrow electrode  33 - 1  for the green LEDs and the narrow electrode  53 - 1  for the blue LEDs, respectively. 
         [0050]    In the second wiring area  5 - 2 , metal bumps  71  are disposed on the left and right of the second wiring area  5 - 2  and in front of the red LEDs  45 , in order to prevent the metal wire  47  from sagging. The metal wire  47  rises to a height of the metal bumps, and then straddles the narrow electrode  33 - 1  for the green LEDs and the narrow electrode  53 - 1  for the blue LEDs. 
         [0051]    Furthermore, in the second wiring area  5 - 2 , a resist resin  72  is applied between the narrow electrode  33 - 1  for the green LEDs and the metal wire  47  and between the narrow electrode  53 - 1  for the blue LEDs and the metal wire  47 , to prevent short-circuits therebetween. In addition, the protective layer  70  is applied over the red LEDs  45 , the metal wire  47 , the metal bumps  71 , and the resist resin  72  to protect each component. 
         [0052]      FIG. 6A  shows a case in which the metal wire  47  for connecting the red LEDs  45  straddles the narrow electrode  33 - 1  for the green LEDs and the narrow electrode  53 - 1  for the blue LEDs in the second wiring area  5 - 2 . The same goes for a case in which metal wire for connecting the green LEDs  35  or metal wire for connecting the blue LEDs  55  straddles the narrow electrodes for the LEDs of the other colors. 
         [0053]      FIG. 6B  shows a state in which in the first wiring area  4 - 1 , the metal wire for connecting the red LEDs  45 , as shown in  FIG. 4 , straddles the electrode  22  for the blue LEDs  25  for producing the white light arrayed in the first mounting area  2 . In the first wiring area  4 - 1 , the red LEDs  45  are connected to each other by bent metal wire  48  in such a manner as to straddle the electrode  22 . 
         [0054]    Although the metal bumps  71  are used in the second wiring area  5 - 2  (see  FIG. 6A ), no meal bump is used in the first wiring area  4 - 1  because a resist resin  73  is applied between the metal wire  48  and the electrode  22 . Note that, the protective layer  70  is applied over the red LEDs  45 , the metal wire  48 , and the resist resin  73  to protect each component. 
         [0055]      FIG. 6B  shows a case in which the metal wire  48  for connecting the red LEDs  45  straddles the electrode  22  for the blue LEDs  25  for producing the white light arrayed in the first mounting area  2 , in the first wiring area  4 - 1 . The same goes for a case in which the metal wire for connecting the green LEDs  35  or the metal wire for connecting the blue LEDs  55  straddles the electrode  22  for the blue LEDs  25  for producing the white light arrayed in the first mounting area  2 . 
         [0056]    The preceding description has been presented only to illustrate and describe exemplary embodiments of the present invention. It is not intended to be exhaustive or to limit the invention to any precise form disclosed. It will be understood by those skilled in the art that various changes may be made and equivalent may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. The invention may be practiced otherwise than is specifically explained and illustrated without departing from its spirit or scope. 
       DESCRIPTION OF THE REFERENCE NUMERALS 
       [0000]    
       
           1  . . . LED module 
           10  . . . aluminum substrate 
           11  . . . first frame member 
           12  . . . second frame member 
           16  . . . phosphor resin 
           20 ,  30 ,  40 ,  50  . . . anode electrode 
           21 ,  31 ,  41 ,  51  . . . cathode electrode 
           22 ,  23  . . . electrode for blue LEDs for producing white light 
           25  . . . blue LED for producing white light 
           32 ,  33  . . . electrode for green LEDs 
           35  . . . green LED 
           42 ,  43  . . . electrode for red LEDs 
           45  . . . red LED 
           52 ,  53  . . . electrode for blue LEDs 
           55  . . . blue LED