Patent Publication Number: US-7906731-B2

Title: Light emitting module, lighting device and display device

Description:
RELATED APPLICATION 
     The present application is a divisional application of U.S. patent application Ser. No. 11/577,584 (now U.S. Pat. No. 7,728,231, issued on Jun. 1, 2010) which is a 371 application from PCT/JP2005/019846 filed on Oct. 24, 2004 which claims priority from Japanese Patent Application No. 2004-318493 filed on Nov. 1, 2004. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a light emitting module that is mounted on a heatsink, and a lighting device and a display device composed of the light emitting module mounted on a heatsink by a socket. 
     BACKGROUND ART 
     Inventors have proposed various lighting devices composed of an LED (light emitting) module in which light emitting units are formed on a front surface of a substrate, a heatsink, and a socket for mounting the LED module to the heatsink (for example, see Japanese Laid-Open Patent Application No. 2004-265626 and Japanese Laid-Open Patent Application No. 2004-265619). 
     The substrate of an LED module is composed of an insulating plate and a metal plate (heat conducting plate) layered together, and the light emitting unit is composed of a plurality of LEDs that are mounted in a central area of the front surface of the insulating plate. The metal plate ensures stiffness of the LED module as well as having a function of conducting heat generated when the light emitting unit (in other words, the LEDS) emits light to the heatsink. 
     The socket is mounted on a flat surface of the heatsink from over the LED module so as to cover the front side thereof. In this mounted state, pressing units of the socket press against edge parts of the insulating plate, thus having a function of pressing the LED module, in other words the metal plate, against the heat sink. 
     DISCLOSURE OF THE INVENTION 
     In the described lighting device, however, there is a problem that even thought the LED module is mounted so as to push against the heatsink, the heat generated when the light emitting unit emits light is not sufficiently conducted to the heatsink. In other words, sufficient heat dissipation properties cannot be obtained in the lighting device. 
     The present invention was conceived in view of the stated problem, and has a object of proving a light emitting module, a lighting device, and a display device that are capable of improving heat dissipation properties during light emission. 
     Note that, because heat is generated during operation, the light emitting module requires some kind of measure for heat dissipation (a heat dissipater). Besides a general heatsink, the body of the lighting device or the display device are also assumed to also function as a heatsink. In the present Description, the term heatsink should be interpreted as including all of these. 
     Means to Solve the Problem 
     As a result of investigating and analyzing conventional lighting devices, the inventors of the present invention found that when an LED module is in a non-mounted state (i.e. not mounted on a heatsink), the LED module is warped such that the central part of the substrate protrudes on the insulating plate side (the opposite side to the heatsink when mounted on the heatsink). For this reason, even if the LED module is mounted on the heatsink, the edges of the substrate (the parts pushed by the pushing units of the socket) contact the heatsink, while, due to the warping of the substrate, the central part of the back surface of the light emitting unit does not contact the heatsink. 
     The substrate of the LED module is obtained from a large-sized material having the same structure as the substrate according to a blanking process. Further investigation by the inventors showed that warping occurs in the blanking process. 
     In order to achieve the stated object, the present invention is a light emitting module used mounted on a heatsink, the light emitting module including: a substrate composed of an insulating plate and a heat conducting plate layered together, and a light emitting unit provided on the insulating plate in a central area of the insulating plate, wherein the substrate is warped such that a central part thereof protrudes on a heatsink side, the heatsink side being a heat conducting plate side of the substrate. 
     According to the stated structure, when the light emitting module is mounted on the heatsink side, the central part, or the vicinity thereof, of the heat conducting plate contacts the heatsink. When the light emitting unit emits light the central part of the light emitting unit is the hottest part and the light emitting unit is located in the central area that excludes the edge parts of the insulating plate, and therefore the place that is the hottest during light emission and the place that contacts the heatsink when the light emitting module is mounted on the heatsink are close to each other. Therefore, the heat generated during light emission is conveyed effectively from the heat conducting plate to the heatsink. 
     Furthermore, the present invention is a lighting device including: a heatsink; a light emitting module including a substrate and a light emitting unit, the substrate being composed of an insulating plate and a heat conducting plate layered together, and the light emitting unit being provided on the insulating plate in a central area of the insulating plate; and a socket for mounting the light emitting module on the heatsink such that the light emitting unit is on a front side, wherein the light emitting module is warped such that a central part thereof protrudes on a heatsink side when the light emitting module is in a mounted state on the heatsink. 
     Furthermore, the present invention is a lighting device including: a heatsink; a light emitting module including a substrate and a light emitting unit, the substrate being composed of an insulating plate and a heat conducting plate layered together, and the light emitting unit being provided on the insulating plate in a central area of the insulating plate; and a socket for mounting the light emitting module on the heatsink such that the light emitting unit is on a front side, wherein the heatsink is warped such that at least a substantially central part of an area thereof in which the light emitting module is to be mounted protrudes on a light emitting module side. 
     Furthermore, the present invention is a display device including: a heatsink; a light emitting module including a substrate and a light emitting unit, the substrate being composed of an insulating plate and a heat conducting plate layered together, and the light emitting unit being provided on the insulating plate in a central area of the insulating plate; and a socket for mounting the light emitting module on the heatsink such that the light emitting unit is on a front side, wherein the light emitting module is warped such that a central part thereof protrudes on a heatsink side when the light emitting module is in amounted state on the heatsink. 
     Effects of the Invention 
     When the light emitting module of the present invention is mounted on a heatsink with, for example, the light emitting unit on the insulating plate at the front side, the part (or the vicinity thereof) of the heat conducting plate that is hottest during light emission contacts the heatsink, and therefore the heat that occurs during light emission is effective conveyed via the heat conducting plate to the heatsink. This improves heat dissipation properties of the light emitting module. 
     Furthermore, in a lighting device of the present invention, when the light emitting module that is warped such that the central part of the substrates protrudes on the heatsink side is mounted on the heatsink by the socket the part (or the vicinity thereof) of the heat conducting plate of the light emitting module that is hottest during light emission contacts the heatsink and therefore the heat that occurs during light emission is effectively conveyed via the heat conducting plate to the heatsink. This improves heat dissipation properties of the light emitting module. 
     Furthermore, in a lighting device of the present invention, when the light emitting module is mounted by a socket to a heatsink that is warped such that a central part protrudes on the light emitting module side, the part (or the vicinity thereof) of the heat conducting plate of the light emitting module that is hottest during light emission contacts the heatsink, and therefore the heat that occurs during light emission is effectively conveyed via the heat conducting plate to the heatsink. This improves heat dissipation properties of the light emitting module. 
     Furthermore, in a display apparatus of the present invention, when the light emitting module that is warped such that the central part of the substrates protrudes on the heatsink side is mounted on the heatsink by the socket, the part (or the vicinity thereof) of the heat conducting plate of the light emitting module that is hottest during light emission contacts the heatsink and therefore the heat that occurs during light emission is effectively conveyed via the heat conducting plate to the heatsink This improves heat dissipation properties of the light emitting module. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective drawing showing a lighting device in an embodiment in a disassembled state; 
         FIG. 2A  is a planar drawing of an LED module;  FIG. 2B  is a cross section along a line X-X of  FIG. 2A  as seen from an arrow A direction; and  FIG. 2C  is a cross section along a line Y-Y of  FIG. 2B  as seen from an arrow B direction; 
         FIG. 3A  is a vertical cross sectional drawing of the LED module; and  FIG. 3B  is an enlarged drawing of a portion of  FIG. 3A  shown by the broken line; 
         FIG. 4  shows the structure of a bottom side of the socket; 
         FIG. 5  is for describing the mounting of the LED module; 
         FIGS. 6A and 6B  show results of measuring the amount that the LED module is warped; 
         FIGS. 7A to 7E  illustrate the process for manufacturing the LED module; 
         FIGS. 8A to 8D  illustrates the processing for manufacturing the metal base substrate; 
         FIG. 9  shows an example of when submounts are used as light emitting bodies; 
         FIG. 10  is a perspective view of a modification example of the socket; and 
         FIG. 11  is a schematic drawing showing a modification example lighting device. 
     
    
    
     NUMERICAL REFERENCES 
       1  lighting device 
       10  socket 
       14 R,  14 L,  14 D,  14 T pushing units 
       60  LED module 
       62  light emitting unit 
       70  heatsink 
       71  flat surface 
     BEST MODE FOR CARRYING OUT THE INVENTION 
     The following describes a light emitting module of the present invention and a lighting device in which the light emitting module is employed, in an embodiment in which LEDs are used as light emitting elements. 
     1. Structure of the Lighting Device 
       FIG. 1  is a perspective drawing showing a lighting device  1  of the embodiment, in a disassembled state. 
     The lighting device  1 , as shown in  FIG. 1 , is composed of an LED module (corresponding to the light emitting module of the present invention)  60 , a heatsink  70 , and a socket  10  that mounts the LED module  60  to the heatsink  70 . 
     The LED module  60 , which is described in detail later, emits light from a light emission unit which is on a surface thereof. A back surface side of the LED module  60  is a metal plate with superior heat conductivity that transfers the heat generated during light emission (this metal plate corresponds to the heat conducting plate of the present invention) to the heatsink  70 . The LED module  60  is mounted to the heatsink  70  by mounting the socket  10  on the heatsink  70  in a state in which the socket  10  is disposed over the LED module  60  so as to cover the front surface of the LED module  60 . 
     (1) Structure of the LED Module  60   
       FIG. 2A  is a planar drawing of the LED module  60 ,  FIG. 2B  is a cross section along a line X-X of  FIG. 2A  as seen from an arrow A direction, and  FIG. 2C  is a cross section along a line Y-Y of  FIG. 2A  as seen from an arrow B direction. Furthermore,  FIG. 3A  is a vertical cross sectional drawing of the LED module  60 , and  FIG. 3B  is an enlarged drawing of the portion of  FIG. 3A  shown by the broken line. 
     As shown in  FIG. 1  to  FIG. 3 , and in particular in  FIG. 2A  and  FIG. 3A , the LED module  60  is principally composed of an insulating plate  632  that has a light emitting unit  62  and a power unit  61  formed on the front side thereof, and a metal plate  631  that is provided on the bottom side of the insulating plate  632  in order to increase the heat dissipation effect. The insulating plate  632  and the metal plate  631  are a layered structure, and together with a wiring pattern formed on the front surface of the insulating plate  632  for supplying power to the light emitting unit  62 , compose a metal base substrate (corresponding to the substrate of the present invention)  63 . 
     The light emitting unit  62 , as shown in the cross sectional drawing of  FIG. 3A  and the enlarged drawing of  FIG. 3B , is composed of: LEDs  6010  which are mounted on a wiring pattern (not illustrated) formed on the part of the insulating substrate  632  that corresponds to the light emitting unit  62 ; resin bodies  6020  which cover respective LEDs  6010 ; a reflective plate  602  that has reflective apertures  603  in parts corresponding to the LEDs  6010 ; and a lens member  601  of which parts corresponding to the reflective apertures  603  of the reflective plate  602  are lens units  604 . 
     As can be seen from  FIG. 2A , in the present embodiment a total of 64 LEDs  6010  are mounted in an eight by eight arrangement in substantially a square shape. Phosphor for converting light emitted from the LEDs  6010  into a desired color of light is included in the resin bodies  6020  that cover the LEDs  6010 . 
     The reflective plate  602  is for reflecting the light emitted from the LEDs  6010  in desired directions. In the present embodiment the reflective plate  602  has trumpet-shaped reflective apertures  603  that widen towards the front side (the side opposite to the insulating plate  632 ). Note that reason for making the reflective apertures  603  trumpet-shaped is to effectively reflect light emitted from the LEDs  6010  to the front side. 
     The lens units  604  fill in the reflecting apertures  603  of the reflective plate  602 , as well as being shaped so as to protrude as semi-spheres from the front surface of the reflecting plate  602 . The lens member  601  including the lens units  604  is made, for example, of highly-transparent resin. Details of the structure of the LED module  60  having the described structure can be found in Japanese Laid-Open Patent Application No. 2003-124528. 
     The width and length of the insulating plate  632  are greater than the width and length of the light emitting unit  62 , thus ensuring a margin surrounding the light emitting unit  62 . In other words, the light emitting unit  62  is formed in a central region that excludes peripheral parts  65  of the insulating plate  632 . 
     As shown in  FIG. 2A , since in the present embodiment the light emitting module  60  has a flat, rectangular shape when seen in planar view and the light emitting unit  62  has a substantially square shape when seen in planar view, the insulating plate  632  has four periphery parts  65   a ,  65   b ,  65   c , and  65   d  on the front surface thereof, corresponding to the four sides of the light emitting unit  62 . When describing the periphery parts  65   a ,  65   b ,  65   c , and  65   d  without reference to a particular one of the four, the reference numeral  65  is used, although this does not appear in the drawings. 
     The power unit  61  is for supplying power to the LEDs  6010 . In the present embodiment the LEDs  6010  are arranged appropriately in series and in parallel to each other, and each line is electrically connected with a corresponding one of power terminals  61 - n  (n being an integer from 1 to 16) by a wiring pattern (not illustrated). Note that the power unit  61  receives power from a power terminal unit  16  of the socket  10 . 
     Furthermore, the LED module  60 , as shown in  FIG. 2B  and  FIG. 2C , bends such that a central part  631   b  of the back surface side is convex. In other words, when viewed from each of the A arrow direction and the B arrow direction, the metal base substrate  63  is warped such that the central part  631   b  of the metal plate  631  is convex on the side that is opposite to the light emitting unit  62 . Note that the central part  631   b  of the metal plate  631  is also the central part of the metal base substrate  63 , and the reference numeral  631   a  is used also to indicate the central part of the metal base substrate  63 . 
     (2) Structure of the Heatsink  70   
     The heatsink  70  is a metal member (an aluminium member, for example) that is a rectangular solid and is highly heat conductive. A plurality of pectinate fins  72  are disposed on a side of the heatsink  70  that is the opposite side to the side on which the LED module  60  is mounted. These pectin fins  72  heighten the heat dissipation effect. 
     As shown in  FIG. 1 , the flat surface  71  on which the LED module  60  is mounted is provided with screw holes  710 ,  711 ,  712  and  713  ( 713  is not illustrated) for screws  800 ,  801 ,  802  and  803  to secure the socket  10 . 
     The LED module  60  is placed on and mounted on the flat surface  71  of the heatsink  70  in an area  73  that is located between a line connecting the screw hole  710  and the screw hole  711  and a line connecting the screw hole  712  and the screw hole  713 . 
     (3) Structure of the Socket  10   
       FIG. 4  shows the structure of the bottom side of the socket. 
     The socket  10 , as shown in  FIG. 1  and  FIG. 4 , is composed of a socket main body  11  and external terminals  16 . The socket main body  11  is formed by, for example, press machining a stainless steel plate. The socket main body  11  has a main wall  12  and side walls  13 R,  13 L and  13 T that extend respectively from three sides of the four sides of the main wall  12 . In the main wall  12  is provided an opening  110  that corresponds to the size of the light emitting unit  62  of the LED module  60 . 
     The side walls  13 R and  13 L, which are on the longer sides of the main wall  12 , bend so as to be substantially at right angles with main wall  12  at a base part with the main wall  12 , and further have a right-angled bend at an intermediate part between the base part and a tip part, so as to extend away from the main wall  12 . On the other hand, the side wall  13 T bends in one place so as to be at substantially a right angle at the base part with the main wall  12  and to extend orthogonal to the main wall  12 . 
     Through holes  130 R,  131 R,  130 L and  131 L are provided in the parts of the side walls  13 R and  13 L that extend parallel with the main wall  12 , in locations corresponding to the screw holes  710 ,  711 ,  712  and  713  of the heatsink  70 . 
     Note that instead of a stainless steel plate, the socket main body  11  may be made using another material that has superior heat dissipation properties such as brass. 
     As shown in  FIG. 1  and  FIG. 4 , four pressing units (corresponding to the pressing units of the present invention)  14 R,  14 L,  14 T and  14 D are formed on the edges of the socket  110  that surround the opening  110 . These pressing units  14 R,  14 L,  14 T and  14 D have a spring structure formed integrally with the socket main body  11 . 
     The pressing units  14 R,  14 L,  14 T and  14 D are formed by leaving T-shape parts connected to the edge of the opening  110  when punching out the opening  110 , and then bending the T-shaped parts. The pressing units  14 R,  14 L,  14 T and  14 D are respectively composed of vertical bars  140 R,  140 L,  140 T and  140 D ( 140 L is not illustrated), horizontal bars  141 R,  141 L,  141 T and  141 D that are supported by the vertical bars  140 R,  140 L,  140 T and  140 D respectively, and pressing contact units  142 R,  143 R,  142 L,  143 L,  142 T,  143 T,  142 D and  143 D that are arc-shaped and provided on either end of respective horizontal bars  141 R,  141 L,  141 T and  141 D. 
     The height of the socket  10  in a thickness direction thereof is designed to be slightly less than the sum of (i) the height of the pressing units  14 R,  14 L,  14 T and  14 D and (ii) the height of the LED module  60 , in order to ensure that the LED module  60  is pressed against the flat surface  71  of the heatsink  70  by the pressing units  14 R,  14 L,  14 T and  14 D. 
     On the inner surface of the main wall  12 , a power terminal unit  16  is provided on the side of the socket main body  11  that does not have a side wall, in a location corresponding to the power terminal  61  of the LED module  60 . The power terminal unit  16 , as shown in  FIG. 4 , has a structure in which external terminals  16 - n  (n being an integer from 1 to 16, and corresponding to the “n” of the power terminals  61 - n  of the LED module  60 ) are held by a terminal holding member  150  (insulating housing). The terminal holding member  150  is made of liquid crystal polymer or resin material that is durable, incombustible material or the like. The external terminal&#39;s  16 - n  are made of phosphor bronze that is superior in terms of both electrical conductivity and durability with respect to insertion and removal. 
     Of the external terminals  16 - n , the parts that extend from the terminal holding member  150  toward the opening  110  are contact units  162 - n  (n being an integer from 1 to 16, and corresponding to the “n” of the power terminals  61 - n  of the LED module  60 ). The contact units  162 - n  have a warped shape such that they are convex in a thickness direction of the socket  100 , away from the main wall  12  side. Note that the reason that the contact units  162 - n  have this shape is to ensure that they contact (electrically connect with) the power terminals  61 - n  of the LED module  60 . 
     On the other hand, of the external terminals  16 - n , the parts that extend from the terminal holding member  150  toward the opposite side to the opening  110  are external contact units for receiving power from an external source. These external connection parts are connected via a connecter (not illustrated) to a common LED driving circuit and, by receiving power, are driven as appropriate. 
     Note that LED module  60  can be removed and replaced by removing the screws  800 ,  801 ,  802  and  803  as shown in FIG  1 . 
     2. Mounting of the LED Module  60   
       FIG. 5  is for describing mounting of the LED module  60 . 
     The LED module  60  having the described structure is placed on the flat surface  71  of the heatsink  70  as shown in process A in  FIG. 5 . Next, with the pressing units  14 R,  14 L,  14 T and  14 D ( 14 R does not appear in the drawing) facing towards the LED module  60 , the socket  10  is lowered from above the LED module  60 . The metal base substrate  63  of the LED module  60  in this state is warped such that the central part  63  protrudes on the heatsink-side. The substantially center part  631   b  of the metal plate  631  contacts the heatsink  70 . 
     Next, as shown by process B, the socket  10  is further lowered, and fitted onto the LED module  60  such that the light emitting unit  62  of the LED module  60  fits in the opening  110  of the socket  10 . With the socket  10  further pressed against the heatsink  70  side, the screws  800 ,  801 ,  802  and  803  (see  FIG. 1 ) are screwed in to fix the socket  10  to the heatsink  70 . 
     When in a state of not being pressed against the heatsink side, the metal base substrate  63  of the LED module  60  is warped such that the central part  631   b  thereof protrudes on the heatsink side. When the LED module  70  is in the mounted state on the heatsink  70 , the edge parts  65  of the insulating plate  632  are pressed by the pressing units  14 R,  14 L,  14 T and  14 D of the socket  10 , thus ensuring that the central part (or the central part and its proximity) of the metal base substrate  63  where heat generation is concentrated during light emission contacts the heatsink  70 . 
     As a result of the described processes, mounting of the LED module  60  to the heatsink  70  with the socket  10  is complete. 
     3. Implementation Example 
     The dimensions of the LED module  60  are, as shown in  FIG. 2A , as follows: a dimension L 1  of the short sides is 23.5 mm, and a dimension L 2  of the long sides is 28.5 mm. The metal plate  631  that composes the metal base substrate  63  is a 1 mm-thick aluminium plate, and the insulating plate  632  is 0.1 mm thick and is made of thermosetting resin that includes filler. A wiring pattern is formed on the insulating plate  632  according to etching or the like using 10 μm-thick copper foil. The resin is epoxy resin. 
     Each LED  6010  mounted on the metal base substrate  63  is substantially cuboid in shape, with a 0.3 mm by 0.3 mm square-shaped base and a height of 0.1 mm, and is made of an InGaN material. Each LED  6010  has a P-type electrode and an N-type electrode on a lower surface, and is flip chip mounted via a bump to a wiring pattern formed on the front surface of the insulating plate  632 . Note that the LEDs  6010  are blue-light emitting LEDs, and the phosphor is yellow-light emitting phosphor, and hence the blue light is converted into white light. 
     The reflective plate  602  is made from a 1 mm-thick aluminium plate, and is attached to the metal base substrate  63  using a white epoxy resin layer. The reason for using a resin layer that is white is to effectively draw light emitted from the LEDs  6010  outside (to the front side). 
     Note that instead of a metal plate such as aluminium, the reflective plate  602  may be a metal plate of another material, white resin, or resin or the like whose front surface (particularly, the surface that composes the reflective apertures) has been plated. Furthermore, when an aluminium plate is used for the reflective plate  602 , the reflecting rate of the reflective plate  602  can be improved and electric insulation can be ensured if, for example, an oxide film is formed on the surfaces that compose the reflective apertures  603  according to alumite treatment. 
     The lens member  601  is made of translucent resin, specifically, epoxy resin. Instead of epoxy resin, the lens member  601  may be made of a translucent resin such as acrylic resin or silicone resin, or of glass or the like. Furthermore, although the lens units  604  are semi-spherical convex lenses in the present embodiment, their shape may be modified according to purpose. 
       FIG. 6  shows results of measuring the amount that the LED module is warped. 
       FIG. 6A  shows warping Z 1  of  FIG. 2C , and  FIG. 6B  shows warping Z 2  of  FIG. 2B . 
     The warping of the LED module  60 , in other words the displacement in the thickness direction Z 1  and Z 2  of the surface of the metal plate  631  (the surface of the opposite side to the insulating plate  632 ) of the metal base substrate  63  with respect to the short sides and the long sides, when the central part  631   b  is used as a reference, gradually becomes concave toward each of the short sides and the long sides. In other words, when seen from either the A arrow direction or the B arrow direction shown in  FIG. 2A , the LED module  60  is a convex curve such that the substantially central part  631   b  of the metal base substrate  63  protrudes parabolically on the side opposite to the insulating plate  632 . 
     4. Manufacture of the LED Module  60   
       FIGS. 7A to 7E  illustrate the process for manufacturing the LED module  60 . 
     First, the metal base substrate  63  is provided. This metal base substrate  63 , as shown in  FIG. 7A , already has a warped shape such that the central part  631   b  of the metal plate  631  protrudes on the side opposite to the insulating plate  632 . The reason that the metal base substrate  63  is warped is as follows. 
       FIGS. 8A to 8D  illustrate the processing for manufacturing the metal base substrate  63 . 
     The metal base substrate  63  used in the LED module  60  is obtained by subjecting a large, original substrate  63   a  such as that shown in  FIG. 8A  to a blanking process. This original substrate  63   a  is rectangular, and is, for example, of a size that enables a total of twenty metal base substrates  63  (five in the long side direction and four in the short side direction) to be obtained. 
     The original substrate  63   a  is made of a large, original metal plate  631   a  of the same material and thickness as the metal plate  631  used in the metal base substrate  63 , and a large, original insulating plate  632   a  of the same material and thickness as the insulating plate  632  used in the metal base substrate  63 . The original metal plate  631   a  and the original insulating plate  632   a  are integrated to form the original substrate  63   a.    
     Here, the original metal plate  631   a  and the original insulating plate  632   a  are integrated by layering as-yet uncured resin that is to form the original insulating plate  623   a  on the front surface of the original metal plate  631   a , and, before the resin cures, subjecting this arrangement to heating and pressuring in order to cure the resin. As a result, formation of the original insulating plate  632   a  and adhesion thereof to the original metal plate  631   a  are carried out simultaneously. 
     After heating (for example, 130° C.) and curing the resin of the original insulating plate  632   a , the temperature of the resin is lowered to room temperature. The degree of shrinkage of the original insulating plate  632   a  that has been formed is lower than the stiffness of the original metal plate  631   a , and therefore a precursory metal base substrate that is obtained by forming the resin of the original insulating plate  632   a  (the precursory metal base substrate being, in other words, the metal base substrate without the wiring pattern) is not significantly warped. 
     A pattern the same as the wiring pattern of the metal base substrates  63  is formed in locations corresponding to the metal base substrates  63  on the original insulating plate  632   a . Each wiring pattern is formed by adhering copper foil to the original insulating plate  632   a  and etching the copper foil in the shape of the pattern. Note that the method described here to form the original substrate  63   a  and the wiring patterns is merely one example, and other methods may be used. 
     Next, using a blanking press, twenty metal base substrates  63  are punched out from the original substrate  63   a  on which the wiring patterns have been formed. This blanking press punches away a punching area  633  of the original substrate  63   a , in other words, the blanking press punches the edges of the metal base substrates  63 . 
     The blanking press has an upper die  650  and a lower die  660 . As one example, the lower die  660  has an concave part  661  that recedes, in the part corresponding to the punching area  633 , while the upper die  650  has an convex part  651  that protrudes, in the part corresponding to the punching area  633 . As one example, the upper die  650  is vertically movable, and arranged such that when the upper die  650  is lowered, the convex part  651  advance into the concave part  661  of the lower die  660 . 
     As shown in  FIG. 8B , the original substrate  63   a  is set on the lower die  660  such that the original insulating plate  632   a  directly contacts the lower die  660 . When the upper die  650  is lowered, the punching area  633  is punched out from around the metal base substrates  63 . 
     Next, as shown in  FIG. 8D , the upper die  650  is raised, thereby removing the concave parts  661  from the convex parts  651 . As a result, twenty metal base substrates  63  are obtained from the large original substrate  63   a . The punched out metal base substrates  63  curve in a convex shape as shown in  FIG. 8D . In other words, at this point the metal base substrates  63  are warped such that the central part  631   b  of the metal plate  631  protrudes on the opposite side to the insulating plate  632 . 
     Next, returning to  FIG. 7 , the LEDS  6010  are mounted in predetermined positions on the insulating plate  632  of the metal base substrate  63 . The LEDs  6010  are mounted by, for example, absorbing each LED  6010  with tip of the collet of an LED mounting device, placing the absorbed LEDs  6010  on corresponding bumps on the wiring pattern formed on the insulating plate  632 , and bonding the LEDs  6010  and the bumps by applying ultrasonic waves. 
     Next, the LEDs  6010  are covered with the resin bodies  6020  (see  FIG. 7B ). This is done by, for example, placing, on the metal base substrate  63  on which the LEDs  6010  have been mounted, a plate-shaped mold that has through holes in portions corresponding to the LEDs  6010 , and filling the mold via the through holes with resin that is to become the resin bodies  6020 . This arrangement is then heated to cure the resin. 
     Next, the reflective plate  602  is attached to the metal base substrate  63  on which the resin bodies  6020  have been formed, as shown in  FIG. 7C , such that the reflective apertures  603  correspond to the resin bodies  6020  (the LEDs). The reflective plate  602  is attached as described earlier, by adhering the reflective plate  602  and the metal base substrate  63  using a white epoxy resin layer (a resin sheet). 
     Finally, the lens member  601  is formed on the reflective plate  602  that has been attached to the metal base substrate  63 , and the LED module  60  as shown in  FIG. 7E  is complete. The lens member  601  is formed by, as shown in  FIG. 7D , injecting resin that is to become the lens member  601  into a mold  605 , in other words, by using a transfer mold method. This mold  605  is, for example, a split mold that has a upper die  610  and a lower die  620 , and parts  621  of the lower die  620  that correspond to the lens units  604  are semi-spherical depressions. 
     5. Effects 
     The LED module  60  having the described structure is prone to reaching particularly high temperatures at a substantially central location of the light emitting unit  62  during light emission. With the LED module  60  of the present invention, since the central part  631   b  that includes the part of the metal plate  631  where the high temperatures occur is in contact with the heatsink  70 , the amount of heat that is conveyed to the heatsink  70  side is greater than in a conventional LED module in which the metal base substrate contacts the heatsink at edge parts. 
     Naturally, when the LED module  60  emits light in the described state, the heat is conveyed to the heatsink  70  through the metal plate  631 . The grater the area of contact between the metal plate  631  and the heatsink  70 , the greater the amount of heat that is conveyed. Hence, the present invention effectively improves heat dissipation properties over conventional structures. 
     While the present invention has been described based on the above embodiment, the present invention is by no means limited to the specific example given as the embodiment. The following are examples of modifications that may be made to the present invention. 
     1. Light Emitting Module and Warping 
     The light emitting (LED) module of the present invention is not limited to the structure described in the above embodiment, and may be a module such as the following. 
     (1) Lens Units 
     In the embodiment the lens member  101  is structured such that the lens units  604  protrude in semi-spherical shapes in parts corresponding to the reflective apertures  603  of the reflective plate  602 , and each lens unit  604  is connected to neighboring lens units  604  by the same resin. However, it is possible for the lens units to be independent lens units, unconnected to neighboring lens units. 
     In such a case, when forming the resin that is to compose the lens units, the amount of warping will be reduced due to the differing heat expansion coefficient of the metal base substrate and the lens units. For this reason, in order to make the LED module in the warped form described in the embodiment, when punching out the metal base substrate it is necessary to make the central part of the metal base substrate protrude on the side opposite to the insulating plate. 
     Conversely, when the lens member  601  is formed with the lens units  604  connected to each other as described in the embodiment, if the amount of warping due to forming the resin of the lens member  601  is too great, the direction in which the metal base substrate is punched out should be the opposite to that in the embodiment (specifically, by setting the original substrate on the lower die with the top and bottom of the original substrate in the opposite way to described the manner in the embodiment). 
     (2) Reflective Plate 
     Although the reflective plate  602  is provided in the embodiment, it is not necessary to have a reflective plate. However, since the stiffness of the metal base substrate is considerably low if a reflective plate is not provided, there is a possibility that the if the lens unit is formed according to the transfer mold method described in the embodiment, the amount of warping will increase due to the differing heat expansion coefficient of the metal base substrate and the lens member. 
     Consequently, in the case of a light emitting module that lacks a reflective plate but has a lens member formed according to a transfer mold method or the like, and in which the metal base substrate exhibits an excessive amount of warping, the amount of warping can be reduced in ways such as the following. The metal base substrate may be punched out in a manner such as described in the embodiment, and a pre-formed lens member may be adhered to the metal base substrate on which light emitting bodies are mounted, using, for example, a resin layer (adhesive sheet). If no reflective plate is provided, lens units may be formed independently with respect to each light emitting unit. Alternatively, independent lens units may be provided respectively for each reflective aperture of the reflective plate. 
     2. Light Emitting Module 
     (1) Substrate 
     The substrate (metal base substrate) of the embodiment is made up of an insulating plate that is a resin member and a heat conducting plate that is a metal plate, which are integrated (formation of the insulating plate in a semi-cured state and attachment thereof to the heat conducting plate being carried out simultaneously). However, it is possible to pre-cure the resin that composes the insulating plate, and then attach the cured insulating plate to the heat conducting plate. 
     (2) Insulating Plate 
     Although the insulating plate of the embodiment is composed of thermosetting resin that includes filler, the insulating plate may be composed of another material, an example of which is glass epoxy. The number of layers composing the insulating plate is by no means limited to the one layer described in the embodiment and the insulating plate may have multiple layers. In the case of a multi-layer structure, the wiring pattern of the insulating plate may be formed on the top layer, may span all layers, or may be formed in some of the multiple layers. 
     (3) Heat Conducting Plate 
     Although a metal plate, specifically an aluminium plate, is used for the heat conducting plate of the embodiment, the heat conducting plate may be made from another material such as copper, steel, magnesium or the like. Furthermore, a material other than metal may be used, examples of which include ceramic material and resin material. However, if ceramic material is used, it is preferable to make the insulating layer ceramic also, in order to maximize the heat dissipation effect of the ceramic. 
     Furthermore, although the insulating plate and the heat conducting plate are substantially the same size in the embodiment, they are not limited to being any particular size, and may differ from each other in size. 
     (4) Light Emitting Unit 
     Although the light emitting unit in the embodiment has, as one example of light emitting elements, LEDs mounted on a wiring pattern on the front surface of the insulating plate, other light emitting elements may be used. One example of such light emitting elements is laser diodes (LD). However, since the light emitted from laser diodes has strong directivity, it may be necessary to provide a diffusion lens or the like to diffuse the light. 
     Furthermore, the light emitting bodies may be light emitting elements mounted in advance on substrates, in other words, submounts. 
       FIG. 9  shows an example of when submounts are used as light emitting bodies. Note that parts that are the same as in the first embodiment have the same numbering as in the first embodiment, and a description thereof is omitted here. 
     A submount  6120  is composed, for example, of a silicon substrate (hereinafter called “Si substrate”)  6121 , alight emitting element, such as an LED  6010 , mounted on atop surface of the Si substrate  6121 , and a resin body  6021  that surrounds the LED  6010 . 
     Note that a first terminal and a second terminal are formed on a bottom surface and the top surface, respectively, of the Si substrate  6121 . The first terminal is electrically connected to one electrode of the LED  6010 , and the second terminal is electrically connected to the other electrode of the LED  6010 . 
     The submount  6120  is mounted to the metal base substrate  63  by, for example, die bonding using silver paste  6125 , connecting the first terminal that is on the bottom side of the Si substrate  6121  via silver paste to the wiring pattern that is on the front side of the insulating plate  632 , and wire bonding the second terminal that is on the front surface of the Si substrate  6121  via a wire  6126  to the wiring pattern of the insulating plate  632 . 
     Note since that the submount  6120 , as shown in  FIG. 9 , mounts the LED  6010  on the Si substrate  6121  in advance, tests such as those for determining whether the mounted LED  6010  illuminates normally can be performed before the submount  6120  is mounted to the metal base substrate  63 . 
     This means that, for example, tested submounts  6120  can be mounted to the metal base substrate  63 , thus obtaining effects such as improvement in manufacturing yield. Furthermore, there is a merit that, when the color of light emitted varies between submounts  6120 , submounts  6120  that are close in color can be selected, and submounts  6120  that achieve a color of light close to the desired color can be mounted together. 
     In the embodiment, a resin body that includes phosphor is formed in and around each LED. White light emission may be realized with this resin by a combination of blue LEDs and yellow phosphor, UV LEDs and RGB phosphor, or another combination. Alternatively, single-color LEDs, such as R, G and B, may be used. 
     Furthermore, instead of barechip LEDs, bullet LEDs, called SMD LEDs, or module LEDs may be used. Note that these LEDs may be mounted by flip chip mounting, or may another method such as die bonding, wire bonding, or a combination of dice bonding and wire bonding. 
     3. Socket 
     The socket  10  in the embodiment is structure to have a light passing unit, in other words the opening  110 , that corresponds to the light emitting unit  62  when the socket  10  covers the LED module  60 , and passes light emitted from the light emitting unit  62 . However, the socket  10  may have any kind of structure provided that the edge parts of either side of the light emitting unit  62  of the insulating plate (at least edge parts that oppose each other across the light emitting unit) in the light emitting module can be pressed relative to the heatsink. 
       FIG. 10  is a perspective view of a modification example of the socket. 
     As shown in  FIG. 10 , a socket  910  in the present modification example differs greatly to the socket  10  of the embodiment in that it is mounted so as to press against the heatsink  70  by being slid along the flat surface  71  of the heatsink  70 . 
     The shape of the socket  910  is essentially the same as the socket  10  in the embodiment, but it has a receiving opening  920  for receiving the light emitting module ( 60 ) which slides in to the arrangement. The receiving opening  920  is formed in the part of the socket  10  of the first embodiment that opposes power terminal unit  16 , in other words, in the side of the socket that is the opposite side to the power terminal unit  16 . 
     Pressing units that press the inserted light emitting module ( 60 ) against the heat sink  70  are provided on the sides of a cutout  925  that is on a top wall  915  of the socket and that composes the light passing unit (in other words, a total of tree places: the opposing long sides and the short side on the power terminal unit  16  side). 
     The socket  910  having this structure achieves substantially the same effects as the first embodiment. In other words, in the present example also, the central part of the metal plate that is the bottom side of the light emitting module ( 60 ) contacts the heatsink  70  due to the socket  10  being pushed against the heatsink  70  by the pushing parts. 
     Consequently, compared to a conventional light emitting module that is warped such that the central part protrudes on the insulating plate side, in the present modification example the contact part of the light emitting module and the heatsink is closer to the center of heat generated during light emission, and the heat during light emission can be conveyed effectively to the heatsink. In other words, heat dissipation properties are improved over a conventional product. 
     4. Pressing Units 
     Although the pressing units of the embodiment have an elastically deformable spring structure, pressing units that are not elastically deformable may be used. In other words, it is sufficient for the pressing units to press the light emitting module against the heatsink when the light emitting module is mounted on the heatsink. The pressing units are not limited to any particular shape, structure or the like. 
     Furthermore, the number of pressing units is not limited to any particular number However, it is preferable for the places that press the light emitting module against the heatsink to be at least locations opposing each other on either side of the light emitting module (to be a pair). Pressing locations that are on either side of the light emitting unit of the light emitting module and that are opposite to each other is effective in increasing the pressure with which the light emitting module is pressed against the heatsink. Furthermore, the pressure can be balanced on either side of the light emitting unit, and the light emitting module can contact the heatsink in a state of being substantially parallel with respect to the flat surface of the heatsink (This state enables the central area or a vicinity thereof of the light emitting module to contact the heatsink.). Note that the embodiment includes four pressing units in two sets of opposing locations in order to reduce the warping of the light emitting module with respect to the lengthwise direction and the short direction. 
     5. Lighting Device 
     In the lighting device in the embodiment, the light emitting module mounting surface of the heatsink is flat, and the light emitting module is warped such that the central part protrudes on the heatsink side. However, the opposite structure is possible. In other words, the surface of the light emitting module that contacts the heatsink may be flat, and the heatsink may be warped such that a central part thereof protrudes on a light emitting module side. 
       FIG. 11  is a schematic drawing showing a modification example of the lighting device. Note that  FIG. 11  shows only the heatsink and light emitting module that are the characteristic portions of the present modification example, and the socket for mounting the light emitting module on the heatsink is not illustrated. 
     The lighting device of the present modification example is composed of a heatsink  950  and a light emitting module  960  as shown in  FIG. 11 , and a socket that is not illustrated. 
     The heatsink  950 , as shown in  FIG. 11 , is warped such that a substantially central part  952  of a surface thereof to which the light emitting module  960  is mounted protrudes on a light emitting module  960  side. Note that a substantially central part  952  of the surface of the heatsink  950  to which the light emitting module  960  is mounted is a part corresponding to a substantial center of a light emitting unit  962  of the light emitting module  960 . 
     On the other hand, the light emitting module  960  has essentially the same structure of the LED module  60  described in the embodiment, but with the exception that the surface (the metal base substrate  964 ) that is mounted on the heatsink  950  is flat in the present modification example. 
     The lighting device having this structure achieves substantially the same effect as the embodiment. In other words, in the embodiment, the LED module is warped such the central part of the light emitting unit protrudes, and the center of the light emitting unit contacts the heatsink. However, in the present modification example, the light emitting module is flat, and the heatsink is warped such that a part thereof corresponding to the center of the light emitting unit protrudes, and contacts the center of the light emitting unit of the light emitting module. 
     Consequently, in the same way as the embodiment, the present modification example ensures the center of the light emitting unit of the light emitting module contacts the heatsink, and therefore the contact part of the light emitting module and the heat sink is close to the center of heat emission during light emission, and heat can be conveyed effectively to the heatsink during light emission. 
     6. Other Remarks 
     (1) Light Emitting Module Warping Amount 
     It is desirable that the amount of warping be within a range of 0.5 μm to 10 μm per 1 mm of the dimension of a predetermined direction (length) of the light emitting module, and preferably within a range of 1 μm to 5 μm. This is because this amount of warping can be realized relatively easily and a relatively high heat dissipation effect can be obtained. 
     Note that the amount of warping is defined as the difference between the most protruding place and the most receding place (however, any burrs on the edge of the light emitting module are excluded). 
     (2) Heatsink Warping Amount 
     It is desirable that the amount of warping be within a range of 0.5 μm to 10 μm per 1 mm of the dimension of a predetermined direction (length) of the heatsink, and preferably within a range of 1 μm to 5 μm. This is because this amount of warping can be realized relatively easily and a relatively high heat dissipation effect can be obtained. 
     (3) Socket and Heatsink 
     Both the embodiment and the modification example have a structure in which the heatsink is larger than the socket, the socket is attached to the heatsink, and the light emitting module is pressed against the heatsink by the socket. 
     However, if the structure is such that, for example, the socket is attached to a main body of the lighting device and the heatsink is mounted on the main body of the lighting device, the heatsink will press the light emitting module, which is held by the socket, from the back side (the heat conducting plate side). In such a case, the light emitting module is pressed relatively, and naturally the effect of the present invention is obtained in the same way as the embodiment. In this case, the pressing units for making the light emitting module and the heatsink contact each other tightly do not have to be provided on the socket side, but may be provided, for example, on the lighting device side. 
     Furthermore, although the light emitting module is warped such that the central part thereof protrudes on the heat conducting plate side, it is possible for the heatsink to protrude in a substantial center of the area where the light emitting module is to the mounted (see  FIG. 11 ). Furthermore, both the light emitting module and the area of the heatsink where the light emitting module is to be mounted may be warped such that a substantial center of both protrude toward each other. 
     Note that in order to obtain ideal heat dissipation properties, both the light emitting module and the heatsink would be flat, and the whole range of the heat conducting plate of the light emitting module would contact the heatsink. 
     (4) Shape of the Light Emitting Module 
     Although the light emitting module in the embodiment and the modification example has a planar shape that is rectangular, it may have a planar shape that is another shape such as square, oval, round, or a polygonal shape such as a pentagonal. In these cases also, it is suitable to provide pressing units on the socket or on another component, such that, when seen in planar view, the pressing units sandwich the light emitting unit and press either side thereof. 
     (5) Display Apparatus 
     The LED module  60  (light emitting module) of the embodiment may be used as a display apparatus with an eight line by eight row arrangement. However, in such a case, it is necessary to modify the wiring pattern such that the LEDs (light emitting bodies) can be turned on individually, and to provide a common lighting control circuit for turning on the LEDs individually to display characters, symbols, and the like. 
     Note that although an example of eight lines by eight rows is given here, the LEDs (light emitting bodies) are not limited to being mounted in an eight line by eight row arrangement. Furthermore, an arrangement in which a plurality (64 in the embodiment) of LEDs (light emitting bodies) are mounted on a substrate as described in the embodiment may be used as one of a plurality of light sources in a display apparatus. 
     INDUSTRIAL APPLICABILITY 
     The present invention can be used for improving heat dissipation properties in a light emitting module mounted on a heatsink by a socket, and in a lighting device and a display device in which the fight emitting module is mounted on a heatsink by a socket.