JP5054331B2 - Lighting equipment using LED - Google Patents

Description

  The present invention relates to a lighting fixture using LEDs.

  Conventionally, LED chips are combined with LED chips and phosphors (fluorescent pigments, fluorescent dyes, etc.) as wavelength conversion materials that are excited by light emitted from the LED chips and emit light of a different emission color from the LED chips. Research and development of light-emitting devices that emit light of a color different from the color of the light is being conducted in various places. As this type of light-emitting device, for example, a white light-emitting device (generally called a white LED) that obtains white light (white light emission spectrum) by combining an LED chip that emits blue light or ultraviolet light and a phosphor. Has been commercialized.

  In addition, with the recent increase in output of white LEDs, research and development for expanding white LEDs into lighting applications has become active, but the above-mentioned white LEDs require a relatively large light output, such as general lighting. When using for a purpose, it is impossible to obtain a desired light output with a single white LED. Therefore, an LED unit in which a plurality of white LEDs are mounted on a single circuit board is configured, and the desired overall LED unit is formed. Generally, light output is ensured (for example, Patent Document 1).

  Conventionally, in an LED unit including a plurality of LED chips and a circuit board on which each LED chip is mounted, the increase in the junction temperature of each LED chip is suppressed and the input power is increased to increase the light output. In order to achieve this, a structure for efficiently radiating the heat generated in the light emitting portion of each LED chip to the outside has been proposed (see, for example, Patent Documents 2 and 3).

  In the LED unit disclosed in Patent Document 2, a metal substrate in which a conductor pattern 203 is formed on a metal plate 201 via an insulating resin layer 202 is employed as a circuit substrate 200 as shown in FIG. The heat generated in each LED chip 10 ′ is transferred to the metal plate 201 through the heat transfer member 210. Here, each LED chip 10 ′ is a GaN-based blue LED chip formed on one surface side of a crystal growth substrate made of a sapphire substrate whose light-emitting portion made of a GaN-based compound semiconductor material is an insulator, and a circuit board The other surface of the crystal growth substrate is a light extraction surface.

Further, in the LED unit disclosed in Patent Document 3, a conductive pattern 203 is formed on a metal plate 201 with an insulating resin layer 202 as shown in FIG. The heat generated in each LED chip 10 ″ is transferred to the metal plate 201. Here, each LED chip 10 ″ has an anode electrode on one surface side. The cathode electrode is formed on the other surface side, and the electrode closer to the circuit board 200 of the anode electrode and the cathode electrode is electrically connected to the first conductor plate 212, and The electrode far from the circuit board 200 is electrically connected to the second conductor plate 213 via a bonding wire 214 made of a fine metal wire. Beauty respective second conductive plate 213 is bonded to the circuit pattern 203 of the circuit board 200.
JP 2003-59332 A JP 2003-168829 A (paragraph [0030] and FIG. 6) JP 2001-203396 A (FIG. 6)

  By the way, when the LED unit having the configuration shown in FIGS. 12 and 13 is used for a lighting fixture, the LED main unit is made of metal, and the metal plate 201 on the circuit board 200 of the LED unit is thermally coupled to the fixture main unit, thereby the LED unit. However, in order to ensure lightning surge resistance, for example, as a sheet-like insulating member between the instrument body and the metal plate 201 of the circuit board 200, for example, Sarcon (registered trademark) ) Such as a rubber sheet-like heat dissipation sheet, and the thermal resistance from the light emitting portion of each LED chip 10 ′, 10 ″ to the instrument body increases, and each LED chip 10 ′, 10 ″ It is necessary to limit the input power to each LED chip 10 ′, 10 ″ so that the junction temperature does not exceed the maximum junction temperature. Higher output of the force has been difficult.

  In addition, when the above-described heat dissipation sheet is interposed between the metal plate 201 of the circuit board 200 and the appliance body, a gap is generated between the metal plate 201 and the heat dissipation sheet due to insufficient adhesion between the metal plate 201 and the heat dissipation sheet. The resistance increased, or the thermal resistance to the fixture body varied for each light emitting part of each LED chip 10 ′, 10 ″.

  In the LED unit disclosed in Patent Document 2, heat generated in the light emitting portion of the LED chip 10 ′ is transferred to the metal plate 201 through the heat transfer member 210 smaller than the size of the LED chip 10 ′. The thermal resistance from the LED chip 10 ′ to the metal plate 201 is relatively large, and when the sapphire substrate that is a crystal growth substrate is mounted so as to be thermally coupled to the metal plate 201, the thermal resistance of the sapphire substrate becomes large. There was also a problem that it ended up.

  This invention is made | formed in view of the said reason, The objective is to provide the lighting fixture using LED which can suppress the temperature rise of an LED chip and can aim at the high output of light output.

According to a first aspect of the present invention, there is provided an LED chip in which an anode electrode is formed on one surface side and a cathode electrode is formed on the other surface side, a chip mounting member made of a metal plate on which the LED chip is mounted, An anode side lead terminal to which the anode electrode is electrically connected, a cathode side lead terminal to which the cathode electrode of the LED chip is electrically connected, a metal instrument body, a chip mounting member, an anode side lead terminal and a cathode e Bei an interposed insulating layer for electrically insulating and thermally coupling the two both between the side lead terminal and the instrument body, the insulating layer is characterized by being formed by a thermosetting adhesive material And

According to the present invention, the heat resistance from the light emitting part of the LED chip to the fixture body can be reduced and heat dissipation can be improved and the temperature rise of the junction temperature of the LED chip can be suppressed compared to the conventional case, so that the input power can be increased. , The light output can be increased. Further, when used with the same light output as before, there is an advantage that the junction temperature of the LED chip can be reduced and the life of the LED chip is prolonged as compared with the conventional one. Furthermore, there is an advantage that it is not necessary to prepare a conventional circuit board and the cost can be reduced . According to the present invention, since the insulating layer is formed of a thermosetting fixing material, a gap is generated between the chip mounting member and the insulating layer due to insufficient adhesion between the chip mounting member and the insulating layer. Therefore, it is possible to prevent the thermal resistance from increasing due to an increase in the thermal resistance or a gap between the chip mounting member and the insulating layer due to the aging of the insulating layer.

  According to a second aspect of the present invention, in the first aspect of the invention, the chip mounting member is continuously formed integrally with one of the anode side lead terminal and the cathode side lead terminal, and the chip mounting member and the anode side are formed. The lead terminal and the cathode side lead terminal are formed integrally with a holding frame of an insulating synthetic resin molded product at the same time.

  According to this invention, since the chip mounting member on which the LED chip is mounted is held by the holding frame, the handling becomes easy, and at least the chip mounting member, the anode side lead terminal, and the cathode side lead terminal Can be inspected before the individual parts are mounted on the instrument body, with the set of the holding frame and the LED chip formed integrally at the same time as individual parts.

  According to a third aspect of the present invention, in the second aspect of the present invention, the holding frame includes a chip mounting member, the anode-side lead terminal, the cathode-side lead terminal, and the instrument main body on a surface facing the instrument main body. Protruding portions for securing an insulation distance between them are projected.

  According to the present invention, the chip mounting member, the anode-side lead terminal, the cathode-side lead terminal, and the instrument body can be reliably electrically insulated regardless of the state of the insulating layer.

According to a fourth aspect of the present invention, there is provided an LED chip in which an anode electrode is formed on one surface side and a cathode electrode is formed on the other surface side, a conductive plate on which the LED chip is mounted on one surface side, and the conductive plate A chip mounting member formed on the one surface side through an insulating portion and having a lead pattern to which the anode electrode and the cathode electrode of the LED chip are electrically connected; a metal instrument body; a chip mounting member and the instrument body; interposed example Bei an insulating layer for electrically insulating and thermally coupling the two both during, the insulating layer is characterized by comprising formed by thermosetting the adhesive material.

According to the present invention, the heat resistance from the light emitting part of the LED chip to the fixture body can be reduced and heat dissipation can be improved and the temperature rise of the junction temperature of the LED chip can be suppressed compared to the conventional case, so that the input power can be increased. , The light output can be increased. Further, when used with the same light output as before, there is an advantage that the junction temperature of the LED chip can be reduced and the life of the LED chip is prolonged as compared with the conventional one. Furthermore, there is an advantage that it is not necessary to prepare a conventional circuit board and the cost can be reduced . According to the present invention, since the insulating layer is formed of a thermosetting fixing material, a gap is generated between the chip mounting member and the insulating layer due to insufficient adhesion between the chip mounting member and the insulating layer. Therefore, it is possible to prevent the thermal resistance from increasing due to an increase in the thermal resistance or a gap between the chip mounting member and the insulating layer due to the aging of the insulating layer.

  According to a fifth aspect of the present invention, in the first to fourth aspects of the present invention, the LED chip has a light emitting portion formed of a GaN-based compound semiconductor material on a main surface side of a conductive substrate made of a SiC substrate or a GaN substrate. And one of the anode electrode and the cathode electrode is formed on the back surface of the conductive substrate.

  According to this invention, since the substrate for crystal growth of the LED chip is a conductive substrate, the thermal resistance of the substrate for crystal growth can be reduced compared with the case where the substrate for crystal growth is a sapphire substrate, and the heat dissipation is reduced. improves.

  According to a sixth aspect of the present invention, in the first to fifth aspects of the present invention, the LED chip and the chip mounting are larger than the chip size of the LED chip and are interposed between the LED chip and the chip mounting member. A submount member that relieves stress acting on the LED chip due to a difference in linear expansion coefficient with the member is provided.

  According to the present invention, it is possible to prevent the LED chip from being damaged due to a difference in linear expansion coefficient between the conductive substrate of the LED chip and the submount member, thereby improving reliability. it can.

  A seventh aspect of the invention is characterized in that, in the first to sixth aspects of the invention, the chip mounting member is made of Cu, and the submount member is made of W or CuW.

  According to the present invention, since the submount member and the chip mounting member can be directly joined, the submount member and the chip can be compared with the case where the submount member and the chip mounting member are joined by the brazing material. The thermal resistance of the joint portion with the mounting member can be reduced.

The invention of claim 8 is characterized in that, in the inventions of claims 1 to 7 , the fixing material comprises a resin sheet containing a filler made of a filler and having a low viscosity when heated.

  In the inventions of claims 1 and 4, since the heat resistance from the light emitting part of the LED chip to the fixture body can be reduced compared to the conventional case, the heat dissipation is improved, and the temperature rise of the junction temperature of the LED chip can be suppressed. Can be increased, and the optical output can be increased.

(Embodiment 1)
Hereinafter, the lighting fixture of this embodiment is demonstrated, referring FIGS. 1-4.

  The lighting fixture of the present embodiment is used as, for example, a spotlight, and is a metal (with respect to an arm 112 having one end coupled to a rotating base 110 fixed on a support base 100 using a shaft screw 111 ( For example, an instrument body 90 made of a metal having a high thermal conductivity such as Al or Cu is coupled using a coupling screw 113.

  The instrument main body 90 is formed in a bottomed cylindrical shape with one surface opened, and stores a plurality of LED chip units 1. Here, in the instrument main body 90, each LED chip unit 1 is mounted on the bottom wall 90a via the insulating layer 80, and the opening portion is closed by the front cover 91. The front cover 91 includes a translucent plate 91 a made of a disk-shaped glass plate and an annular window frame 91 b that holds the translucent plate 91 a, and the window frame 91 b is attached to the instrument main body 90. . Here, in this embodiment, as the insulating layer 80, a resin sheet containing a filler made of a filler such as silica or alumina and having a low viscosity when heated (for example, an epoxy resin sheet highly filled with a filler made of fused silica) A thermosetting fixing material made of organic green sheets), which has electrical insulation properties, high thermal conductivity, high fluidity during heating, and high adhesion to uneven surfaces. The LED chip unit 1 and the instrument main body 90 can be joined by heating the epoxy resin sheet after the epoxy resin sheet is interposed between the LED chip unit 1 and the instrument main body 90. The translucent plate 91a is not limited to a glass substrate, but may be formed of a translucent material, and controls the light distribution of light emitted from each LED chip unit 1 to the translucent plate 91a. You may provide the lens to perform integrally.

  The plurality of LED chip units 1 housed in the appliance main body 90 are connected in series by a plurality of lead wires 93, and the lead wires 93 at both ends of the series circuit of the plurality of LED chip units 1 are connected to the appliance main body 90. The power is supplied from a power supply circuit (not shown) through an insertion hole 90c provided in the bottom wall 90a. As the power supply circuit, for example, a power supply circuit having a rectifier circuit composed of a diode bridge that rectifies and smoothes the AC output of an AC power supply such as a commercial power supply and a smoothing capacitor that smoothes the output of the rectifier circuit is employed. That's fine. Moreover, in this embodiment, although the several LED chip unit 1 in the instrument main body 90 is connected in series, the connection relation of the several LED chip unit 1 does not specifically limit, For example, it connects in parallel. You may make it, and you may combine a serial connection and a parallel connection.

  The LED chip unit 1 includes a rectangular plate-shaped LED chip 10, a chip mounting member 41 that is formed in a rectangular plate shape larger than the chip size of the LED chip 10 and on which the LED chip 10 is mounted, and one side of the chip mounting member 41. A strip-shaped lead terminal 42 that is continuously formed integrally with the edge, a T-shaped lead terminal 43 that is spaced apart from the other side edge of the chip mounting member 41, and an LED that is disposed so as to surround the LED chip 10. A reflector (reflector) 50 that reflects light emitted from the side surface of the chip 10 to the front of the LED chip 10 (upward in FIG. 1), and a protective cover 60 that is attached to the front side of the reflector 50 so as to cover the LED chip 10. And.

  The chip mounting member 41 and the lead terminals 42 and 43 are formed using a lead frame made of a metal plate (for example, a copper plate), and the chip mounting member 41 and the lead terminals 42 and 43 have insulating properties. The inner lead portions 42a and 43a of the lead terminals 42 and 43 and the chip mounting member 41 are disposed inside the holding frame 45 at the same time and integrally formed with a holding frame 45 made of a synthetic resin molded product having a rectangular frame shape. Outer lead portions 42 b and 43 b of the lead terminals 42 and 43 are arranged outside the holding frame 45. Here, the above-described insulating layer 80 is interposed between the chip mounting member 41 and the lead terminals 42 and 43 and the instrument main body 90, and the insulating layer 80 includes the chip mounting member 41 and the lead terminals 42 and 43. And the instrument body 90 are electrically insulated and thermally coupled. In the present embodiment, the holding frame 45, the chip mounting member 41, the lead terminals 42 and 43, the reflector 50, the protective cover 60, and the insulating layer 80 constitute a package of the LED chip 10. . In this embodiment, the insulating layer 80 is provided for each LED chip unit 1, but one insulating layer 80 slightly smaller than the bottom wall 90 a of the instrument body 90 is provided for the plurality of LED chip units 1. May be shared.

  The material of the lead frame is not limited to copper, and may be phosphor bronze, for example. In this embodiment, the chip mounting member 41 and the lead terminals 42 and 43 are formed integrally with the holding frame 45 at the same time. However, the holding frame 45 is not necessarily provided, and the chip mounting member 41 and the lead terminal 42 are not necessarily provided. There is also no need to form a continuous integral. However, when the chip mounting member 41 and the lead terminal 42 are continuously formed integrally and the above-described holding frame 45 is provided, the LED chip unit 1 can be easily handled as an individual component at the time of assembly or the like. There is an advantage that an individual test can be easily performed before the unit 1 is mounted on the instrument main body 90.

  The LED chip 10 is a GaN-based blue LED chip that emits blue light, and is a conductive substrate made of an n-type SiC substrate that has a lattice constant and a crystal structure close to GaN as a crystal growth substrate and has conductivity compared to a sapphire substrate. The light emitting portion 12 formed of a GaN-based compound semiconductor material and having, for example, a double hetero structure is formed on the main surface side of the conductive substrate 11 by an epitaxial growth method (for example, MOVPE method). ), A cathode electrode (n electrode) (not shown) is formed on the back surface of the conductive substrate 11, and an anode electrode (p electrode) (not shown) is formed on the surface of the light emitting portion 12 (the outermost surface on the main surface side of the conductive substrate 11). ) Is formed. In short, the LED chip 10 has an anode electrode formed on one surface side and a cathode electrode formed on the other surface side. The cathode electrode and the anode electrode are composed of a laminated film of a Ni film and an Au film, but the material of the cathode electrode and the anode electrode is not particularly limited, and a material capable of obtaining good ohmic characteristics For example, Al or the like may be employed.

  In the present embodiment, the one lead terminal 42 constitutes a cathode side lead terminal, and the other lead terminal 43 constitutes an anode side lead terminal. In the present embodiment, the LED chip 10 is mounted on the chip mounting member 41 such that the light emitting unit 12 of the LED chip 10 is farther away from the chip mounting member 41 than the conductive substrate 11. You may make it mount in the chip mounting member 41 so that 12 may become the side near the chip mounting member 41 rather than the electroconductive board | substrate 11. FIG. Considering the light extraction efficiency, it is desirable to arrange the light emitting unit 12 on the side away from the chip mounting member 41. However, in this embodiment, the conductive substrate 11 and the light emitting unit 12 have the same refractive index. Therefore, even if the light emitting unit 12 is disposed on the side close to the chip mounting member 41, the light extraction loss does not become too large.

  In addition, the reflector 50 has a circular frame-like shape and is formed in a shape in which the opening area increases as the distance from the LED chip 10 increases in the thickness direction of the LED chip 10, and has a sheet shape having an insulating property. The lead terminals 42 and 43 are fixed by a fixing material 55 made of an adhesive film. The outer peripheral shape of the reflector 50 and the fixing material 55 is formed in a rectangular shape that is slightly smaller than the inner peripheral shape of the holding frame 45.

  Here, as a material of the reflector 50, a material (for example, Al) having a relatively high reflectance with respect to light emitted from the LED chip 10 (here, blue light) may be employed. Note that a circular opening 55 a corresponding to the opening of the reflector 50 is formed in the fixing material 55. Moreover, it is desirable to pot a transparent sealing resin (for example, silicone resin) for sealing the LED chip 10 inside the reflector 50.

  The protective cover 60 has a dome-shaped cover portion 62 disposed so that its center is located on the center line along the thickness direction of the LED chip 10, and continuously protrudes sideways from the periphery of the opening of the cover portion 62. An annular positioning rib 61a is projected from the peripheral portion of the surface of the flange portion 61 on the reflector 50 side so that the flange portion 61 can be stably positioned with respect to the reflector 50. Yes. Note that the protective cover 60 may be bonded to the reflector 50 using, for example, an adhesive (for example, a silicone resin, an epoxy resin, or the like).

  In addition, the protective cover 60 is a mixture of a translucent material such as silicone and a particulate yellow phosphor that emits broad yellow light that is excited by the blue light emitted from the LED chip 10. It is composed of a molded product. Therefore, the LED chip unit 1 in the present embodiment also serves as a color conversion unit in which the protective cover 60 is excited by the light emitted from the LED chip 10 and emits light of a color different from the emission color of the LED chip 10. The LED chip unit 1 as a whole constitutes a white LED that outputs white light composed of combined light of blue light emitted from the LED chip 10 and light emitted from the yellow phosphor. The translucent material used as the material of the protective cover 60 is not limited to silicone, and for example, an acrylic resin, an epoxy resin, glass, or the like may be employed. Further, the phosphor mixed with the translucent material used as the material of the protective cover 60 is not limited to the yellow phosphor, and for example, white light can be obtained by mixing a red phosphor and a green phosphor. Further, when the light emission color of the LED chip 10 is the same as the desired light emission color of the LED chip unit 1, it is not necessary to mix a phosphor with the light transmissive material.

  By the way, in this embodiment, the blue LED chip whose emission color is blue is adopted as the LED chip 10 as described above, and the SiC substrate is adopted as the conductive substrate 11, but GaN is used instead of the SiC substrate. A substrate may be used. When a SiC substrate or a GaN substrate is used, as can be seen from Table 1 below, when a sapphire substrate that is an insulator is used as a substrate for crystal growth as in Patent Document 2 above. In comparison, the crystal growth substrate has a high thermal conductivity and a low thermal resistance. Further, the light emission color of the LED chip 10 is not limited to blue, and may be, for example, red or green. That is, the material of the light-emitting portion 12 of the LED chip 10 is not limited to the GaN-based compound semiconductor material, and a GaAs-based compound semiconductor material, a GaP-based compound semiconductor material, or the like may be employed according to the emission color of the LED chip 10. Further, the conductive substrate 11 is not limited to the SiC substrate, and may be appropriately selected from, for example, a GaAs substrate and a GsP substrate according to the material of the light emitting unit 12.

  Further, the LED chip 10 is formed on the above-described chip mounting member 41 in a rectangular plate shape having a size larger than the chip size of the LED chip 10, and is caused by a difference in linear expansion coefficient between the LED chip 10 and the chip mounting member 41. The LED chip 10 is mounted via a submount member 30 that relieves stress. The submount member 30 has not only a function of relieving the stress but also a heat conduction function of transferring heat generated in the LED chip 10 to a range wider than the chip size of the LED chip 10 in the chip mounting member 41. The surface area of the chip mounting member 41 on the LED chip 10 side is desirably sufficiently larger than the surface area of the LED chip on the chip mounting member 41 side. For example, in order to efficiently perform waste heat from the 0.3 to 1.0 mm square LED chip 1, the contact area between the chip mounting member 41 and the insulating layer 80 is increased and the heat of the LED chip 10 is wide. It is preferable to reduce the thermal resistance so as to conduct heat uniformly over the entire area, and the area of the surface on the LED chip 10 side of the chip mounting member 41 formed using the lead frame is defined as the chip mounting member in the LED chip 10. It is desirable that the surface area on the 41st side be 10 times or more. Here, the submount member 30 only needs to have the function of relieving the stress, and the thickness dimension is made smaller than the thickness dimension of the circuit board in the LED unit described in Patent Documents 1 to 3 above. Therefore, the heat resistance can be reduced by adopting a material having a relatively large thermal conductivity.

  In this embodiment, CuW is adopted as the material of the submount member 30. In the LED chip 10, the cathode electrode has the inner lead portion of the one lead terminal 42 via the submount member 30 and the chip mounting member 41. 42a, and the anode electrode is electrically connected to the inner lead portion 43a of the other lead terminal 43 through a bonding wire 14 made of a fine metal wire (for example, a gold fine wire, an aluminum fine wire, etc.). Yes. The lead wires 93 are electrically connected to the outer lead portions 42b and 43b of the lead terminals 42 and 43 through joints 95 made of solder, respectively.

  The material of the submount member 30 is not limited to CuW. For example, as can be seen from Table 2 below, the material of the submount member 30 is a material whose linear expansion coefficient is relatively close to 6H—SiC which is the material of the conductive substrate 11 and whose thermal conductivity is relatively high. For example, W, AlN, composite SiC, Si, or the like may be employed. However, when an insulator such as AlN or composite SiC is adopted as the submount member 30, for example, an appropriate conductor pattern to be bonded to the anode electrode is provided on the surface of the submount member 30 on the LED chip 10 side. The conductor pattern and the inner lead portion 42a of the one lead terminal 42 may be electrically connected via a bonding wire.

  Here, when the material of the chip mounting member 41 is Cu, if CuW or W is adopted as the submount member 30, the submount member 30 and the chip mounting member 41 can be directly joined. As shown in Table 3, compared to the case where the submount member 30 and the chip mounting member 41 are bonded using a brazing material, the bonding area between the submount member 30 and the chip mounting member 41 can be increased and the submount member can be increased. The thermal resistance of the joint between 30 and the chip mounting member 41 can be reduced. The LED chip 10 and the submount member 30 may be bonded using lead-free solder such as AuSn or SnAgCu. However, when bonding using AuSn, the LED chip 10 and the submount member 30 are on the bonding surface of the submount member 30. Therefore, a pretreatment for forming a metal layer made of Au or Ag is necessary.

  Further, when W is used as the material of the submount member 30 and the submount member 30 and the chip mounting member 41 are directly joined, as shown in Table 4 below, the submount member 30 and the chip mounting member 41 are made of silver. Compared with the case where it joins using brazing, thermal conductivity becomes large and thermal resistance can be reduced. When the material of the chip mounting member 41 is Cu and AlN, composite SiC, or the like is adopted as the material of the submount member 30, the chip mounting member 41 and the submount member 30 are made of lead such as AuSn and SnAgCu. Bonding may be performed using free solder. However, when bonding using AuSn, pretreatment for forming a metal layer made of Au or Ag on the bonding surface of the chip mounting member 41 is necessary.

  In the lighting fixture of this embodiment described above, the heat generated in each LED chip unit 1 during lighting is passed through the insulating layer 80 without passing through the circuit board 200 shown in FIGS. The circuit board 200 of the LED unit shown in FIG. 12 and FIG. 13 can be dissipated to the bottom wall 90a of the instrument main body 90, and the insulating layer 80 can be provided with a rubber sheet-like heat dissipation sheet interposed therebetween. Compared to the configuration in which the heat is coupled via the LED chip 10, the distance and the thermal resistance from the light emitting portion 12 of the LED chip 10 to the fixture main body 90 can be reduced to improve heat dissipation, and the junction temperature of the light emitting portion 12 of the LED chip 10 is increased. Therefore, the input power can be increased and the optical output can be increased. Moreover, when using it by the same light output as the structure of the conventional lighting fixture, compared with the structure of the conventional lighting fixture, there exists an advantage that the junction temperature of the LED chip 10 can be reduced and the lifetime of LED chip 10 becomes long. Furthermore, there is no need to prepare a circuit board 200 as in the prior art, and the cost can be reduced, and the degree of freedom of arrangement of the LED chip units 1 is high, and the number of LED chip units 1 can be easily changed and the layout can be easily changed. There is also an advantage.

  Here, the submount member 30 interposed between the LED chip 10 and the chip mounting member 41 as described above is used when the difference in linear expansion coefficient between the LED chip 10 and the chip mounting member 41 is relatively small. Is not necessarily provided, and the distance between the LED chip 10 and the bottom wall 90a of the metal instrument body 90 is greater when the submount member 30 is not interposed between the LED chip 10 and the chip mounting member 41. Becomes shorter, the thermal resistance from the light emitting part 12 of the LED chip 10 to the instrument body 90 can be further reduced, and the heat dissipation is further improved, so that the light output can be further increased.

  By the way, when the above-described heat dissipation sheet (thermal conductive sheet) or insulating sheet is adopted as the insulating layer 80, the chip mounting member 41, the lead terminals 42 and 43, the holding frame 45, and the insulating layer 80 are insufficiently adhered. As shown in FIG. 5, a gap 85 is generated between the two to increase the thermal resistance, or the thermal resistance to the instrument body 90 varies for each LED chip unit 1. Therefore, when a load is applied to the holding frame 45 It is necessary to manage the torque. Further, when insulating grease is employed as the insulating layer 80, the chip mounting member 41, the lead terminals 42 and 43, and the holding frame 45 and the insulating layer 80 are interposed as shown in FIG. However, due to the secular change (viscosity change, shrinkage, etc.) of the insulating layer 80, a gap 86 is generated between them as shown in FIG. 6 (b). There is a possibility that the thermal resistance increases or the thermal resistance up to the instrument main body 90 varies for each LED chip unit 1.

On the other hand, in the present embodiment, the above-described thermosetting fixing material (for example, an epoxy resin sheet highly filled with a filler such as silica or alumina) is employed as the insulating layer 80, and the insulating layer 80 adheres to the uneven surface. Since the contact reliability is improved, the secular change is reduced, and the gap 85 between the chip mounting member 41 and the insulating layer 80 is generated due to insufficient contact between the chip mounting member 41 and the insulating layer 80, resulting in heat. It is possible to prevent the thermal resistance from increasing due to the increase in resistance or the occurrence of the gap 86 between the chip mounting member 41 and the insulating layer 80 due to aging of the insulating layer 80. In order to suppress the thermal resistance of the insulating layer 80 to 1 K / W or less when the effective contact area for heat transfer in the insulating layer 80 is 25 mm ² and the thickness of the insulating layer 80 is 0.1 mm, the insulating layer Although it is necessary to satisfy the condition that the thermal conductivity of 80 is 4 W / m · K or more, if the above-described organic green sheet is employed, this condition can also be satisfied.

(Embodiment 2)
The basic configuration of the luminaire using the LED of this embodiment is substantially the same as that of the first embodiment, and the shape of the holding frame 45 in the LED chip unit 1 is slightly different as shown in FIG. Since other configurations are the same as those of the first embodiment, illustration and description thereof are omitted.

  By the way, in Embodiment 1, each surface on the bottom wall 90a side of the instrument body 90 in the chip mounting member 41 and each of the lead terminals 42 and 43 of the LED chip unit 1 and the surface on the bottom wall 90a side of the instrument body 90 in the holding frame 45. Are substantially flush with each other, and when an insulating material such as an epoxy resin is used as the material of the insulating layer 80, the insulating layer 80 may be formed depending on the load applied to the holding frame 45 as shown in FIG. ) And the chip mounting member 41 and the lead terminals 42 and 43 and the instrument main body 90 may not be electrically insulated.

  On the other hand, as shown in FIG. 8A, the holding frame 45 in the present embodiment has a chip mounting member 41 and each lead terminal at each of four corners on the surface facing the bottom wall 90a of the instrument body 90. A convex portion 45 is secured to secure an insulation distance between 42 and 43 and the instrument main body 90. In addition, the protrusion dimension of the convex part 45 is set smaller than the thickness dimension of the organic green sheet employ | adopted as the insulating layer 80. FIG.

  Thus, in this embodiment, the chip mounting member 41 and the lead terminals 42 and 43 and the instrument body 90 can be reliably electrically insulated regardless of the state of the insulating layer 80. That is, in this embodiment, a load is applied after an organic green sheet used as the insulating layer 80 is interposed between the bottom wall 90a of the instrument body 90 and the chip mounting member 41 and the lead terminals 42 and 43 during assembly. Even when the organic green sheet protrudes as shown in FIG. 8A, the distance between the chip mounting member 41 and the lead terminals 42 and 43 and the bottom wall 90a of the instrument main body 90 is Since it does not become smaller than a protrusion dimension, the chip | tip mounting member 41 and each lead terminal 42 and 43 and the instrument main body 90 can be electrically insulated more reliably.

(Embodiment 3)
The structure of the lighting fixture using LED of this embodiment is as substantially the same as Embodiment 1, Comprising: As shown in FIGS. 9-11, the structure of the LED chip unit 1 is different. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted.

  In the LED chip unit 1 in the present embodiment, instead of providing the chip mounting member 41, the lead terminals 42 and 43, and the holding frame 45 in the first embodiment, a rectangular plate-like conductive material on which the LED chip 10 is mounted on one surface side. A chip mounting member 70 having lead patterns 73 and 73 formed on the one surface side of the plate 71 and the conductive plate 71 via the insulating portion 72 and electrically connected to the anode electrode and the cathode electrode of the LED chip 10, respectively. The submount member 30 is interposed between the conductive plate 71 and the LED chip 10, and the insulating layer 80 made of an organic green sheet is interposed between the conductive plate 71 and the bottom wall 90 a of the instrument body 90. Differences are made.

  As the material of the conductive plate 71, for example, a material having conductivity and relatively high thermal conductivity such as copper and phosphor bronze may be adopted. As the material of the lead patterns 73 and 73, for example, copper is used. Adopt it. Further, as a material of the insulating portion 72 of the chip mounting member 70, for example, a resin having an insulating property such as a glass epoxy resin, a polyimide resin, or a phenol resin may be employed. Here, in the chip mounting member 70, a rectangular window hole 75 exposing a part of the one surface of the conductive plate 71 is formed at the center of the insulating part 72, and the LED chip 10 is located inside the window hole 75. The conductive plate 71 is mounted on the conductive plate 71 via the submount member 30 joined to the one surface side. In addition, since the electroconductive plate 71 should just have the thickness similar to the lead frame which mounts the LED chip 10, the thickness dimension is the thickness dimension of the circuit board in the LED unit described in the said patent documents 1-3. It can be made smaller than

  In this embodiment, an anode electrode (not shown) on one surface side (upper surface side in FIG. 10) of the LED chip 10 is connected to one end portion (inner lead portion) of one lead pattern 73 via the bonding wire W1. The cathode electrode (not shown) on the other surface side (the lower surface side in FIG. 10) of the LED chip 10 is electrically connected to one end portion (inner lead portion) of the other lead pattern 73 via the bonding wire W2. The other end of each lead pattern 73 is electrically connected to the lead wire 93 via a joint 95 made of solder. In the present embodiment, the chip mounting member 70, the reflector 50, and the protective cover 60 constitute the LED chip 10 package.

  In the lighting fixture of this embodiment described above, the heat generated in each LED chip unit 1 during lighting is passed through the insulating layer 80 without passing through the circuit board 200 shown in FIGS. The circuit board 200 of the LED unit shown in FIG. 12 and FIG. 13 can be dissipated to the bottom wall 90a of the instrument main body 90, and the insulating layer 80 can be provided with a rubber sheet-like heat dissipation sheet interposed therebetween. Compared to the configuration in which the heat is coupled via the LED chip 10, the distance and the thermal resistance from the light emitting portion 12 of the LED chip 10 to the fixture main body 90 can be reduced to improve heat dissipation, and the junction temperature of the light emitting portion 12 of the LED chip 10 is increased. Therefore, the input power can be increased and the optical output can be increased. Moreover, when using it by the same light output as the structure of the conventional lighting fixture, compared with the structure of the conventional lighting fixture, there exists an advantage that the junction temperature of the LED chip 10 can be reduced and the lifetime of LED chip 10 becomes long. Furthermore, there is no need to prepare a circuit board 200 as in the prior art, and the cost can be reduced, and the degree of freedom of arrangement of the LED chip units 1 is high, and the number of LED chip units 1 can be easily changed and the layout can be easily changed. There is also an advantage.

  By the way, in the lighting fixture of this embodiment, if the plane size of the organic green sheet used as the insulating layer 80 is set larger than the plane size of the conductive plate 71, the organic green sheet and the conductive plate 71 have the same plane size. Compared with the case where it is formed, the creeping distance between the conductive plate 71 and the metal fixture body 90 can be increased, and lightning surge resistance when used as a light source for a lighting fixture can be improved. (However, creepage distances generally required for indoor lighting fixtures and outdoor lighting fixtures are different, and outdoor lighting fixtures require longer creepage distances). Here, as for the thickness of the organic green sheet, it is necessary to design the thickness in accordance with the required withstand voltage for lightning surge resistance, but it is desirable to set it thinner from the viewpoint of reducing the thermal resistance. Therefore, regarding the organic green sheet, after setting the thickness, the plane size may be set so as to satisfy the creepage distance requirement.

  Further, as described above, the submount member 30 interposed between the LED chip 10 and the conductive plate 71 of the chip mounting member 70 has a difference in linear expansion coefficient between the LED chip 10 and the conductive plate 71. If the submount member 30 is not interposed between the LED chip 10 and the conductive plate 71, the LED chip 10 and the bottom wall 90 a of the metal instrument body 90 are not necessarily provided. The distance between the LED chip 10 is shortened, the thermal resistance from the light emitting part 12 of the LED chip 10 to the instrument body 90 can be further reduced, and the heat dissipation is further improved, so that the light output is further increased. I can plan.

  Also in this embodiment, the LED chip unit 1 can be easily handled as an individual part during assembly or the like, and the individual inspection can be easily performed before each LED chip unit 1 is mounted on the instrument main body 90. There is.

FIG. 2 is a schematic cross-sectional view of a main part showing Embodiment 1. It is the schematic side view which showed the same and was partly fractured. It is a principal part schematic perspective view in the same as the above. It is a principal part disassembled perspective view in the same as the above. It is principal part explanatory drawing same as the above. It is principal part explanatory drawing same as the above. FIG. 6 is a schematic exploded perspective view of main parts in a second embodiment. It is principal part explanatory drawing same as the above. FIG. 6 is a schematic perspective view showing a main part of a third embodiment. It is a principal part schematic sectional drawing which shows the same as the above. It is a principal part disassembled perspective view in the same as the above. It is a schematic sectional drawing of the LED unit which shows a prior art example. It is a schematic block diagram of the LED unit which shows another prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 LED chip unit 10 LED chip 11 Conductive substrate 12 Light emission part 14 Bonding wire 30 Submount member 41 Chip mounting member 42 Lead terminal (cathode side lead terminal)
43 Lead terminal (Anode lead terminal)
50 Reflector 60 Protective Cover 70 Chip Mounting Member 71 Conductive Plate 72 Insulating Part 73 Lead Pattern 80 Insulating Layer (Resin Sheet)
90 Instrument body

Claims (8)

An LED chip in which an anode electrode is formed on one surface side and a cathode electrode is formed on the other surface side, a chip mounting member made of a metal plate on which the LED chip is mounted, and the anode electrode of the LED chip are electrically connected An anode side lead terminal, a cathode side lead terminal to which the cathode electrode of the LED chip is electrically connected, a metal instrument body, a chip mounting member, an anode side lead terminal, a cathode side lead terminal, and an instrument body interposed example Bei and electrically insulates and insulating layer both thermally coupled both during, the insulating layer is illuminated using LED characterized by comprising formed by thermosetting the adhesive material Instruments.   The chip mounting member is continuously and integrally formed on one of the anode side lead terminal and the cathode side lead terminal, and the chip mounting member, the anode side lead terminal, and the cathode side lead terminal are insulating synthetic resins. The lighting fixture using LED according to claim 1, wherein the lighting fixture is formed integrally with a holding frame of a molded product at the same time.   The holding frame is provided with a projecting portion for securing an insulating distance between the chip mounting member, the anode-side lead terminal, and the cathode-side lead terminal and the instrument body on a surface facing the instrument body. The lighting fixture using LED of Claim 2 characterized by becoming. An LED chip having an anode electrode formed on one surface side and a cathode electrode formed on the other surface side, a conductive plate on which the LED chip is mounted on one surface side, and an insulating portion on the one surface side of the conductive plate A chip mounting member having a lead pattern that is electrically connected to an anode electrode and a cathode electrode of the LED chip, a metal instrument body, and a chip mounting member and the instrument body. electrically insulating and e Bei an insulating layer for thermally coupling the two, an insulating layer, an illumination fixture using the LED, characterized in that formed by formed by a thermosetting adhesive material.   The LED chip includes a light emitting portion formed of a GaN-based compound semiconductor material on a main surface side of a conductive substrate made of a SiC substrate or a GaN substrate, and one of the anode electrode and the cathode electrode is formed on the back surface of the conductive substrate. The lighting fixture using LED of any one of Claim 1 thru | or 4 characterized by the above-mentioned.   Stress acting on the LED chip due to a difference in linear expansion coefficient between the LED chip and the chip mounting member that is larger than the chip size of the LED chip and interposed between the LED chip and the chip mounting member The illumination fixture using LED of any one of Claims 1 thru | or 5 characterized by including the submount member which relieve | moderates.   The lighting device using an LED according to claim 6, wherein the chip mounting member is made of Cu, and the submount member is made of W or CuW. Lighting the fixing material, using an LED as claimed in any one of claims 1 to 7, characterized in Rukoto such a resin sheet for low viscosity during content to and heating the filling material consisting of filler Instruments .

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