JP2011091135A - Light emitting module and lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting module and a lighting system preventing a warpage of a substrate using ceramics. <P>SOLUTION: The light emitting module 10 includes: the substrate 11 made of ceramics; a metal pattern 12 provided on a surface of the substrate in a dispersed manner; a semiconductor light emitting element 13 mounted on the surface of the metal pattern; and a metal member 14 provided on a rear surface of the substrate and having a thickness smaller than that of the metal pattern, wherein a volume ratio of the metal member on the rear surface of the substrate to the metal pattern on the surface of the substrate is 50% or higher. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a light emitting module and a lighting device using a semiconductor light emitting element such as a light emitting diode as a light source.

  In recent years, light-emitting diodes have been adopted as light sources for relatively large lighting devices such as offices and general lighting due to their improved luminous efficiency, and further higher output is required. In order to achieve high output, an important issue is how to efficiently dissipate heat generated during light emission of the light emitting diode. For example, Patent Document 1 discloses a package for a semiconductor light-emitting device including a substrate having a particularly thick copper layer, that is, a light-emitting module using a DCB (Direct Copper Bonding) substrate, and particularly in paragraph [0026]. Because this package uses a highly heat conductive material, the heat from the light emitting diode can be efficiently transferred and dissipated, and the ability to efficiently conduct and release heat from the light emitting diode is Potentially allowing operation at higher current densities without the risk of damage to the light emitting diode. In addition, all elements of the package have a closely matched coefficient of thermal expansion, enabling semiconductor light emission that can potentially operate at higher temperatures without risking damage to the light emitting diode. A package for the device is shown.

  Patent Document 2 uses a ceramic circuit board having high thermal conductivity as a substrate on which a light emitting diode is mounted as one of heat dissipation means for increasing the power of the light emitting diode (paragraph number [0004]). A semiconductor light emitting device having a heat dissipation structure in which solder cracks do not affect the performance of the module in the modularization by lead-free solder bonding of the circuit board and the heat dissipation member is shown (paragraph number [0017]).

JP 2005-79593 A JP 2009-212367 A

  On the other hand, in a light emitting module using this type of DCB substrate or activated brazing (AMB), a metal pattern for light emitting diode wiring is formed on the surface of the ceramic substrate, and a heat radiating member is formed on the back surface. Metal members for joining are respectively formed, and the heat of the light emitting diode is effectively radiated. The metal pattern for wiring is generally made of copper or aluminum with good electrical conductivity, and the metal member on the back surface usually exhibits a heat dissipation function without having an electrical connection function. Consists of a flat plate-shaped metal such as copper or aluminum, and these metal patterns and metal members on the back side are means for joining the ceramic substrate with solder or the like, or copper foil is directly welded to the ceramic substrate It is joined by means for causing.

  As described above, the DCB substrate or the AMB substrate is configured by joining metals having different materials and different coefficients of thermal expansion from ceramics, and the shape of the metal pattern is different between the front and back surfaces. When exposed to the atmosphere, the entire substrate is significantly warped.

  When the entire substrate is warped, there is a problem that the handling property is deteriorated in the manufacturing stage of the light emitting module, and at the same time, the contact property with the heat radiating member such as a case member or a heat sink is poor after the manufacturing. Therefore, the heat of the light emitting diode cannot be effectively radiated. As a result, the luminous efficiency is lowered, and there is a problem that a predetermined luminous flux cannot be obtained. Further, since a gap is formed between the substrate and the case member or the heat radiating member due to the warpage of the substrate, there is a possibility that the substrate itself may crack and be damaged when the substrate is fixed by means such as screwing. .

  For this reason, Patent Document 1 shows that all elements of the package are configured to have a coefficient of thermal expansion that closely matches. However, as described above, the metal is partially bonded to the surface of the substrate made of ceramics in order to form a wiring pattern. On the other hand, the metal is joined to the back surface so as to form a flat plate having an integral shape over substantially the entire surface in order to exert a heat radiation effect. For this reason, the metal on the front side is small, the metal on the back side is increased, and the amount of metal on the front and back sides of the substrate, in other words, the heat capacity is different. For this reason, even if it is made to code the coefficient of thermal expansion of all the elements, the board | substrate curvature by the difference in heat capacity cannot be prevented.

  Furthermore, what is shown in Patent Document 2 prevents the occurrence of solder cracks when a bonding pattern (a metal member on the back surface) is bonded to a heat dissipation substrate (a heat dissipation member for installing a module) via a solder layer. For this purpose, the heat dissipation board and the bonding pattern are formed of the same material or a material having substantially the same coefficient of thermal expansion, and an open region is provided between the bonding pattern and the heat dissipation board in the solder layer, so that the crack progresses. Is prevented from reaching the main joint, and is not disclosed for preventing warpage of the entire substrate made of a ceramic substrate.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a light emitting module and a lighting device capable of preventing warpage in a substrate using ceramics.

  The invention of the light emitting module according to claim 1 includes a substrate made of ceramics; a metal pattern distributed on the surface of the substrate; a semiconductor light emitting element mounted on the surface of the metal pattern; and provided on the back surface of the substrate And a metal member thinner than the metal pattern, wherein the volume ratio of the metal member on the back surface of the substrate to the metal pattern on the substrate surface is 50% or more. According to the present invention, the ceramic member is provided on the back surface of the substrate and has a metal member thinner than the metal pattern, and the volume ratio of the metal member on the back surface of the substrate to the metal pattern on the substrate surface is 50% or more. It is possible to prevent warpage in the used substrate.

  In the present invention, the light emitting module is preferably applied to a relatively large lighting apparatus for facilities / businesses such as an office that performs general lighting from the ceiling or the like, but is a small illumination for general lighting such as a house. The present invention may also be applied to a device, or a lamp with a base using a light emitting diode as a light source.

  The substrate is a member for disposing a semiconductor light emitting element such as a light emitting diode chip as a light source, and a sintered body made of a compound such as aluminum nitride, silicon nitride, alumina, alumina and zirconia is allowed. The shape is preferably formed into a plurality of, for example, a square or a rectangle constituting a surface module necessary for arranging light emitting diode chips with a predetermined interval. It may be a polygonal shape such as an octagon cut out of the shape, a circle or an ellipse, etc., or a long line that constitutes a line module, all for obtaining the desired light distribution characteristics Is acceptable.

  The metal pattern provided on the surface of the substrate forms a wiring pattern, and it is preferable that a semiconductor light emitting element such as a light emitting diode chip is mounted and disposed on the wiring pattern. Means for mounting and the like are not limited to specific ones. The material is preferably made of copper having good conductivity, but all metals having good conductivity, such as copper alloy, aluminum and aluminum alloy, are acceptable.

  In addition, the metal pattern is preferably arranged in a matrix form with a predetermined interval on the substrate by these metals, but the metal pattern is regularly arranged in a regular order such as a staggered pattern or a radial pattern. A part or the whole may be arranged, or may be randomly arranged, and is not limited to the specified arrangement configuration.

  The semiconductor light-emitting element mounted on the surface of the metal pattern is preferably composed of a light-emitting diode chip, but a light-emitting element using a semiconductor laser, organic EL, or the like as a light source is allowed. The semiconductor light-emitting element is preferably one in which a plurality of semiconductor light-emitting elements are mounted on one metal pattern, but the necessary number is selected according to the application of illumination. For example, one element per one metal pattern May be implemented. The semiconductor light emitting element is preferably configured to emit white light, but may be configured to be red, blue, green, or a combination of various colors depending on the use of the lighting device.

  The metal member, which is provided on the back side of the board and is thinner than the metal pattern, is a member for installing the light emitting module on a heat radiating member such as a case member or heat sink, and usually has a heat radiating function without having an electrical connection function. Although it is preferable that it is made of copper from the viewpoint of exhibiting it, all metals having good thermal conductivity such as copper alloy, aluminum and aluminum alloy are allowed. In addition, in order to improve heat dissipation, the metal member composed of these metals is preferably composed of an integral flat plate shape, but all of them need to be integrally continuous. Not only the condition but also a part in which a notch is formed may be separated and dispersed.

  The metal pattern and metal member described above are preferably bonded to a ceramic substrate by bonding a thin plate-shaped metal plate by soldering means such as solder. In the case of copper, for example, a sheet of copper foil is used. Oxidized copper foil may be placed on a ceramic substrate and heated to about 1050 ° C. so that it can be joined by means such as welding the copper foil directly to the ceramic substrate. Is not limited. Further, the metal pattern and the metal member may be composed of a thin metal layer formed by etching.

  The volume ratio of the metal member on the back surface of the substrate to the metal pattern on the substrate surface is determined by fixing the volume of the metal pattern on the substrate surface and appropriately selecting the thickness dimension of the metal member on the back surface of the substrate. However, conversely, the volume ratio with respect to the metal pattern on the substrate surface is fixed by fixing the volume of the metal member on the back surface and appropriately selecting the thickness dimension of the metal pattern on the substrate surface. May be 50% or more.

 The volume of the metal pattern on the front surface and the volume of the metal member on the back surface may be adjusted by making the thickness dimension constant, appropriately selecting the surface area value, and setting the volume ratio. These values may be set in combination. Moreover, you may make it set combining the thickness dimension and the surface area value of both the metal pattern of a board | substrate surface, and the metal member of a board | substrate back surface.

  Moreover, even if the volume of the metal pattern on the substrate surface is set only by the metal pattern on which the semiconductor light emitting element is mounted, the semiconductor light emitting element is not mounted. The metal pattern may be configured together with the members constituting the frame, and the volume of the metal pattern on the substrate surface including these members may be set. In addition, the volume of the metal member on the back side of the board is configured with the metal member together with the member constituting the terminal portion or the member constituting the frame for board reinforcement, and the volume of the metal member on the back side of the board including these members is set. It may be done.

  These semiconductor light-emitting elements are not mounted, for example, the members constituting the terminal portions and the members constituting the substrate reinforcing frame are made of the same material as the metal pattern or metal member on which the semiconductor light-emitting elements are mounted. Although it is preferable, it may be composed of different materials.

  Furthermore, the volume ratio is allowed to be as close to 100% as possible when the volume ratio is 50% or more, but is preferably about 50 to 120%. If it is less than 50%, the difference in heat capacity between the metal on the front surface side and the back surface side is large, and it becomes difficult to prevent warping of the ceramic substrate. If it exceeds 120%, the temperature at the time of bonding is high (about 1050 ° C.), so that the warped shape tends to be curved into a convex shape at room temperature after cooling, and the adhesion between the substrate and the case body is improved. Getting worse.

  In the present invention, “front surface” means a surface on the light emitting part side in the light emitting module, and “back surface” means a surface on the opposite side to the light emitting part side.

  According to a second aspect of the present invention, in the light emitting module according to the first aspect, a part of the metal pattern provided on the surface of the substrate is provided in a long shape on the outer peripheral portion of the substrate. And According to the present invention, a part of the metal pattern is provided in a long shape on the outer peripheral part of the substrate, so that the metal pattern provided on the outer peripheral part of the substrate acts as a reinforcing frame on the outer peripheral part of the substrate. None, it is possible to prevent the substrate from warping and to prevent generation of cracks in the outer peripheral portion.

  In the present invention, the metal pattern that is partly provided on the outer peripheral portion of the substrate is provided so as to avoid the terminal portion provided on the outer peripheral portion of the substrate, for example, the short side of the rectangular substrate When the terminal board is provided on the board, it is possible to effectively use the dead space in the board by avoiding the terminal board and providing the long side along the outer periphery so as to face each other on the long side. However, it is preferable because it does not increase the size of the substrate. However, it may be provided continuously or partially discontinuously around the entire periphery of the substrate.

  Further, the metal pattern forming the reinforcing frame is preferably provided by the same metal material as the metal pattern for mounting the semiconductor light emitting element, but is made of a different material and by a different process. Also good.

  According to a third aspect of the present invention, in the light emitting module according to the first or second aspect, the substrate has a mounting hole for screw tightening, and a part of the metal pattern provided on the surface is provided around the mounting hole. It is characterized by being. According to the present invention, since the metal pattern is partially provided around the mounting hole, the metal pattern provided around the mounting hole functions as a reinforcing frame in the mounting hole for screw tightening. The occurrence of cracks in the screw tightening portion can be prevented.

  In the present invention, it is preferable that a part of the metal pattern is provided around the attachment hole and the metal pattern is provided continuously around the attachment hole. However, the metal pattern may be partly discontinuous. Further, the metal pattern forming the reinforcing frame of the mounting hole is preferably provided by the same metal material simultaneously with the metal pattern for mounting the semiconductor light emitting element and the metal pattern forming the reinforcing frame of the outer peripheral portion. It may be provided by another process.

  The lighting device according to a fourth aspect includes the light emitting module according to any one of the first to third aspects; an instrument body on which the light emitting module is disposed; and a lighting device that lights the light emitting module. It is characterized by that. According to the present invention, by using the light emitting module according to any one of claims 1 to 3, an illuminating device having a predetermined light flux in which a decrease in luminous efficiency is prevented is configured.

  In the present invention, it is preferable that the lighting device is a combination of a plurality of light emitting modules to form a relatively long large lighting fixture for facilities / businesses such as a long office. You may make it comprise the small illuminating device for general illuminations, such as an object.

  The instrument main body is preferably made of a metal such as a steel plate, stainless steel or aluminum having good thermal conductivity. For example, PBT (polybutylene terephthalate) is a synthetic resin having heat resistance, light resistance, and electrical insulation. It may be configured by.

  For example, the lighting device includes a lighting circuit that converts an AC voltage of 100 V into a DC voltage of 24 V and supplies the converted voltage to a light emitting diode chip. The lighting device may be built in the instrument body or may be provided separately from the instrument body. Good. Moreover, you may comprise so that it may have a light control function.

  According to the first aspect of the present invention, the metal member provided on the back surface of the substrate is thinner than the thickness of the metal pattern, and the volume ratio of the metal member on the back surface of the substrate to the metal pattern on the substrate surface is 50% or more. Thus, it is possible to provide a light emitting module capable of preventing warpage in a substrate using ceramics.

  According to the second aspect of the present invention, a part of the metal pattern is provided in a long shape on the outer periphery of the substrate, so that the metal pattern provided on the outer periphery of the substrate is reinforced at the outer periphery of the substrate. It can act as a frame to prevent the substrate from warping and to prevent the occurrence of cracks in the outer periphery.

  According to the third aspect of the present invention, the metal pattern is provided around the mounting hole, so that the metal pattern provided around the mounting hole is a reinforcing frame in the mounting hole for screw tightening. Thus, the occurrence of cracks in the screw tightening portion can be prevented.

  According to the fourth aspect of the present invention, by using the light emitting module according to any one of the first to third aspects, it is possible to provide an illuminating device having a predetermined light flux in which a decrease in luminous efficiency is prevented.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which expands and shows typically the light emitting module which concerns on the 1st Embodiment of this invention, (a) is a front view, (b) is sectional drawing which follows the bb line | wire of (a) figure, (c) ) Is a rear view. The lighting device which similarly uses a light emitting module is shown, (a) is a longitudinal cross-sectional view, (b) is a bottom view. Similarly, it is the figure which expands and shows the 1st modification in a light emitting module typically, (a) is a front view, (b) is a sectional view which meets the bb line of (a) figure, (c) is the back. Figure. Similarly, it is the figure which expands and shows the 2nd modification in a light emitting module typically, (a) is a front view, (b) is sectional drawing which follows the bb line of (a) figure. Similarly, it is a diagram in which the light emitting module in the second modified example is schematically enlarged and partly cut away, (a) is a cross-sectional view corresponding to FIG. 4 (b), and (b) is the conventional FIG. Sectional drawing equivalent to b). It is a figure which expands and shows typically a light emitting module concerning a 2nd embodiment of the present invention, (a) is a front view, (b) is a sectional view which meets a bb line of (a) figure, (c) ) Is a rear view.

  Hereinafter, embodiments of a light emitting module according to the present invention and an illumination device using the light emitting module will be described.

  First, the configuration of the light emitting module will be described. As shown in FIG. 1, a light emitting module 10 of this embodiment is configured by mounting a light emitting diode, which is a semiconductor light emitting element, on a DCB substrate. The light emitting module 10 includes a substrate 11 made of ceramics, and a copper plate provided on the surface of the substrate. The metal pattern 12 comprises a semiconductor light emitting element 13 comprising a light emitting diode mounted on the surface of the metal pattern, and a metal member 14 comprising a copper plate provided on the back surface of the substrate.

  The substrate 11 is a member for disposing the semiconductor light emitting element 13, and is constituted by a rectangular flat plate made of ceramics, in this embodiment, a rectangular flat plate made of aluminum nitride. A metal pattern 12 for forming a wiring pattern is formed on the surface of the substrate. In Fig.1 (a), 11a is an attachment hole for the screw fastening for installing a light emitting module in the case body etc. of an illuminating device.

  The metal pattern 12 is separated and dispersed in two places on the surface of the substrate 11 made of ceramics, and is provided along the longitudinal direction of the substrate. In FIG. 1A, these dispersed metal patterns 12a and 12b are arranged adjacent to each other in the central region of the substrate 11 along the longitudinal direction so as to have a predetermined interval s for electrical insulation. And it joins to the surface (upper surface in FIG.1 (b)) of the board | substrate 11 with solder. The surface of each of the metal patterns 12a and 12b is plated with nickel (Ni) to prevent oxidation. Gold (Au), silver (Ag), or the like may be plated. Since these metals are plated so as to cover the surfaces of the metal patterns 12a and 12b, the light emitted from the semiconductor light emitting element can be effectively reflected, and the efficiency can be improved by reducing the light loss. it can. Incidentally, the reflectance of copper that is not plated is about 60%, but the reflectance can be improved to about 95% by silver plating.

  The semiconductor light emitting element 13 is mounted on the surface of the metal pattern 12 configured as described above. The semiconductor light emitting element is composed of a light emitting diode chip (hereinafter referred to as “LED chip”), and the LED chip 13 is provided with a plurality of LED chips having the same performance. Consists of a blue LED chip with high brightness and high output. A plurality of blue LED chips 13 are arranged and mounted on each metal pattern 12a, 12b in a matrix form with two each having a substantially equal interval. In this embodiment, since the substrate is constituted by a DCB substrate, the LED chip can be provided with a large-capacity chip having a chip angle of about 1 mm (1.1 to 1.5 W).

  Each blue LED chip 13 mounted on the metal pattern 12 as described above is filled with a sealing member 15 in which a yellow phosphor is mixed with a transparent silicone resin. The blue LED chip 13 excites the yellow phosphor. Yellow light is emitted, and this yellow light and blue light are mixed to emit white light. The LED chip 13 is connected to the metal patterns 12a and 12b by a bonding wire w made of a gold wire, and the four LED chips 13 are connected in series.

  The metal member 14 made of a copper plate provided on the back surface of the ceramic substrate 11 is formed of a metal plate made of a copper plate thinner than the plate thickness of the metal pattern 12 provided on the surface of the substrate 11. The metal member 14 is joined to the back surface of the substrate 11 made of ceramics by soldering, and is configured to have a flat plate shape that is integral with the back surface of the substrate (FIG. 1C).

  As described above, the light emitting module 10 made of the DCB substrate is configured. In the light emitting module 10, the volume ratio of the metal member 14 made of the copper plate on the back surface of the substrate 11 to the metal pattern 12 made of the copper plate on the surface of the ceramic substrate 11 is 50% or more. It is comprised so that it may become. In the present embodiment, the substrate 11, the metal pattern 12, and the metal member 14 were configured to have the following dimensions and volumes.

In FIG. 1A, the copper plate of the left metal pattern 12a has a plate thickness of about 0.25 mm and an area of about 40 mm ^2, and the copper plate of the right metal pattern 12b has a plate thickness of left and right. Similarly, the area was set to about 0.25 mm, the area was set to about 80 mm ² , the thickness of the copper plate in the metal pattern 12 on the entire surface was 0.25 mm, and the total area was set to about 120 mm ² .

Further, the copper plate of the metal member 14 on the back surface was configured to have a plate thickness of about 0.2 mm thinner than the plate thickness of the metal pattern 12 on the front surface and an area of about 140 mm ² .

The substrate 11 is made of aluminum nitride having a plate thickness of about 0.25 mm and an area of about 322 mm ² larger than the copper plate of the metal member 14 on the back surface. The metal member 14 is provided on the back surface of the substrate, and a blank is provided on the entire circumference. And joined.

Thus, the volume of the metal pattern 12 on the front surface is about 30 mm ³ and the volume of the metal member 14 on the back surface is about 28 mm ³ , and the volume ratio of the metal member 14 on the back surface of the substrate 11 to the metal pattern 12 on the surface of the substrate 11 is about 93%. Thus, it was configured to be close to 100% at a target of 50% or more.

  In the present embodiment, as described above, the thickness of the metal member 14 provided on the back surface of the ceramic substrate 11 is made thinner than the thickness of the metal pattern 12, that is, the metal pattern 12 on the surface is fixed. Then, the thickness and surface area of the metal member 14 on the back surface were adjusted, and the volume ratio of the metal member 14 on the back surface of the substrate with respect to the metal pattern 12 on the substrate surface was made close to 100% to control the warpage of the substrate.

  As a result, the metal pattern 12 on the substrate surface and the metal member 14 on the back surface of the substrate are made of a copper plate made of the same material to eliminate the difference in the coefficient of thermal expansion of the metal between the front and back surfaces of the ceramic substrate 11, and The volume ratio of the metal member 14 on the back surface of the substrate with respect to the metal pattern 12 was set to about 93% so that the difference in heat capacity between the front and back surfaces was minimized. Thereby, the light emitting module 10 which can prevent the curvature by the heat | fever of the board | substrate 11 which uses ceramics was comprised.

  According to the light emitting module 10, when the LED chip 13 is mounted on the metal pattern 12 by die bonding in the manufacturing stage, the substrate is hardly warped even if it is exposed to a high temperature atmosphere of about 300 ° C. Moreover, the problem that handling property worsens in a manufacturing stage can also be improved.

  As described above, the light emitting module 10 having a DCB substrate and a thin plate shape with a rectangular outer shape is configured. As shown in FIG. 2, the light emitting module is incorporated into a fixture main body to constitute a lighting device.

  The illuminating device 20 of this embodiment is a small downlight that uses an LED as a light source, and includes the light emitting module 10 described above, a fixture main body 21 in which the light emitting module is disposed, and a lighting device 22 that lights the light emitting module. Is done.

  As shown in FIG. 2 (a), the instrument main body 21 is made of aluminum die casting, and is configured as a cylindrical case member having a substantially circular cross section having openings at both ends. A partition plate 21a for disposing the light emitting module 10 is integrally formed at the opening side of one end portion (downward in FIG. 2A) inside the cylindrical body. The partition plate 21a is a support portion for supporting the light emitting module 10 on the instrument main body, and has a flat surface (a lower surface in FIG. 2A) serving as a heat radiating portion.

 The light emitting module 10 is placed on the flat surface of the partition plate 21a, and using the mounting holes 11a provided in the substrate 11, the surrounding four places are fastened to the partition plate 21a with screws, and the copper plate on the back surface of the substrate 11 is secured. The metal member 14 made of is firmly attached and fixed to the partition plate 21a made of aluminum.

 At this time, since the substrate of the light emitting module 10 is not warped, a gap is not formed between the substrate 11 and the partition plate 21a, so that a crack is generated in the substrate 11 during screw tightening. There is no fear. In addition, the contact with the partition plate 21a for heat radiation is not deteriorated, and the heat of the light emitting diode can be effectively radiated.

  In addition, even if the flatness of the partition plate 21a is poor and the substrate 11 is warped and fixed, the metal pattern 12 is arranged in a distributed manner along the left and right longitudinal directions, so that it can flexibly cope with the warp. In addition, cracks and the like are less likely to occur, and it is possible to fix them closely.

  On the surface side of the light emitting module 10 fixed to the partition plate 21a as described above, a reflector 23 is provided so as to surround each LED chip 13. The reflectors 23 are made of a white synthetic resin having light resistance, heat resistance and electrical insulation, for example, PBT (polybutylene terephthalate) and the like, and are mounted on the metal patterns 12 a and 12 b of the light emitting module 10. A circular light inlet 23a having a diameter capable of enclosing the LED chip 13 and a “mortar-shaped” reflecting surface 23b having a paraboloidal surface positioned so as to surround the four LED chips 13 are provided. It is integrally formed. Thereby, the light emission part A in which the optical axis xx of the light emitting module 10 and the optical axis yy of the reflector 23 substantially coincide is configured.

  The lighting device 22 for lighting the LED chip 13 is composed of circuit components constituting a lighting circuit for the four LED chips of the light emitting module 10. The lighting device 22 converts the AC voltage 100 V into the DC voltage 24 V and supplies a constant current to each LED chip 13. It is configured to supply a direct current. The lighting device 22 configured as described above is housed inside the fixture body 21, and a power terminal block 24 for supplying commercial power to the lighting device is provided in the opening on the other end side.

 In the figure, 25 is a decorative frame provided at one end of the instrument body 21 facing the light emitting part A, 25a is a transparent cover member provided on the decorative frame, and 26 is for supporting the instrument body 21 on the ceiling X. It is a support made of a leaf spring.

  The downlight type illumination device 20 configured as described above is installed on the ceiling X, which is the installation surface, by connecting a single unit or a plurality of units using a feeding cable. First, a power supply line is connected to the power supply terminal block 24, and a circular installation hole 30 is formed at a predetermined position of the ceiling X as shown by a one-dot chain line in FIG. Next, the support tool 26 made of a leaf spring of the instrument body 21 is bent inward by hand and inserted into the installation hole 30 together with the instrument body, and the hand is released from the support tool 26. As a result, the leaf spring returns to its original state due to its own elasticity and presses against the inner surface of the installation hole 30, and the fixture body 21 is fixed to the ceiling X by the pressing force, and the upper surface of the decorative frame 25 contacts the ceiling surface X. Determine the position. In this state, the cut end of the installation hole 30 is beautifully covered with the decorative frame 25.

  When the lighting device 20 installed above is turned on, the light emitted from each LED chip 13 is reflected by the reflecting surface 23b made of the rotating paraboloid of the reflector 23, spreads downward in a substantially circular shape, and is emitted. Provide the desired illumination. At this time, the light emitted from the LED chip 13 is reflected by a metal such as nickel, silver or gold plated on the surfaces of the metal patterns 12a and 12b, and the substrate 11 is made of white ceramics. Therefore, it is possible to perform illumination with little light loss by reflecting light on the substrate surface.

  Further, the heat generated from each LED chip 13 is transmitted to the metal pattern 12 → the substrate 11 → the metal member 14 on the back surface, and further to the partition plate 21a → the instrument body 21 of the instrument body to be radiated to the outside. At this time, the metal pattern 12 and the metal member 14 are made of copper having good thermal conductivity, the substrate 11 is also made of ceramic having thermal conductivity, and the instrument body is also made of aluminum having good thermal conductivity, Since it is also transmitted to the main body side wall having a large surface area, it is effectively radiated to the outside.

  Moreover, since the metal patterns 12a and 12b on which the LED chip 13 is mounted are disposed along the longitudinal direction of the substrate 11, the heat generated from the LED chip is transmitted along the longitudinal direction of the substrate having a large heat capacity. Can be dissipated more effectively.

  In addition, the light emitting module 10 is configured without warping, and the metal member 14 on the back surface of the substrate is securely adhered and fixed to the partition plate 21a of the instrument body 21, so that there is no heat loss and is more effective. Heat is dissipated.

  By these heat dissipation actions, a decrease in light conversion efficiency in each LED chip 13 can be suppressed and a decrease in luminous flux can be prevented, and bright illumination with a predetermined illuminance can be performed. At the same time, the life of the LED chip can be extended.

  As described above, according to the present embodiment, the volume ratio of the metal member 14 on the back surface of the substrate to the metal pattern 12 on the substrate surface made of ceramics is set to about 93%, so that the difference in heat capacity between the front and back surfaces is minimized. It is possible to provide the light emitting module 10 capable of reliably preventing the warp due to heat of the substrate 11 using ceramics. At the same time, the metal pattern 12 on the substrate surface and the metal member 14 on the back surface of the substrate are made of a copper plate made of the same material to eliminate the difference in the coefficient of thermal expansion of the metal between the front and back surfaces of the ceramic substrate. The light emitting module 10 that can be more reliably prevented can be provided.

  Further, the thickness of the metal member 14 provided on the back surface of the substrate 11 made of ceramic is formed to be thinner than the thickness of the metal pattern 12 on the front surface, that is, the metal pattern 12 on the front surface is fixed and the metal member 14 on the back surface is fixed. The substrate thickness was adjusted and the volume ratio of the metal member 14 on the back surface of the substrate to the metal pattern 12 on the surface of the substrate was adjusted to be close to 100% to control the warpage of the substrate. As a result, it is possible to control with a simple substrate back surface that has a flat plate shape for heat dissipation without a complicated wiring pattern, and it is easy to adjust the volume, and a predetermined volume ratio can be realized with certainty. In addition, a light emitting module excellent in manufacturability can be provided.

  Since it becomes possible to reliably prevent warpage due to heat of the substrate 11 using ceramics, it is difficult for the substrate to warp even when exposed to a high-temperature atmosphere in the manufacturing stage of the light emitting module 10. Moreover, the problem that handling property worsens in the manufacturing stage of a light emitting module can also be improved.

  In addition, since the substrate of the light emitting module 10 is not warped, no gap is formed between the substrate 11 and the partition plate 21a, and there is no risk of cracks in the substrate when screwed. . Moreover, the contact property with the partition plate 21a for heat radiation is not deteriorated, and the heat of the light emitting diode can be effectively radiated, and an illumination device that performs bright illumination with a predetermined illuminance can be provided.

  In the present embodiment, the metal member 14 on the back surface of the substrate is formed as an integral flat plate, but may be provided separately and dispersed as shown in FIG. That is, as shown in FIGS. 3B and 3C, the metal member 14 is separated and distributed in two places with respect to the back surface of the ceramic substrate 11, and is provided along the longitudinal direction of the substrate. It is done. 3 (b) and 3 (c), the metal members 14a and 14b located on the left and right sides are arranged adjacent to each other so as to have a predetermined interval s along the longitudinal direction in the central region of the back surface of the substrate 11. Then, it is bonded to the back surface of the substrate 11 with solder.

 In this case, the left and right metal members 14a and 14b are disposed so as to be located directly below the LED chip 13 mounted on the surface. In other words, the predetermined interval s is provided so as to avoid directly under the LED chip. As a result, the heat generated from the LED chip 13 can be transmitted to the metal members 14a and 14b located directly below the ceramic substrate 11 with a shortened heat conduction path. Can be efficiently dissipated. Incidentally, when the interval s is located immediately below the LED chip 13, a space is formed immediately below the LED chip, and the thermal resistance increases, so that heat cannot be radiated effectively. In particular, when combined with the ceramic substrate 11 that does not have high thermal conductivity, the heat from the LED chip 13 is difficult to disperse in the left and right within the ceramic substrate 11, and therefore the thermal conductivity is further deteriorated.

 In addition, the LED chip 13 is mounted on each of the left and right metal patterns 12a and 12b, and two LED chips are mounted, and the light emitting part A is configured by a total of four LED chips. Alternatively, a single LED chip may be mounted, and a larger number of LED chips may be arranged to form a light emitting unit A that achieves higher output.

  That is, as shown in FIG. 4, a plurality of, in this embodiment, 20 metal patterns 12g are arranged in a distributed manner on the surface of a rectangular substrate 11 made of ceramics. The metal pattern 12g is arranged in a matrix shape with 5 pieces horizontally and 4 pieces vertically along the longitudinal direction of the rectangular substrate 11 and is joined to the surface of the substrate 11 by soldering. The surface of each metal pattern 12g is plated with nickel (Ni) to prevent oxidation in the same manner as described above. Gold (Au), silver (Ag), or the like may be plated.

  As shown in FIG. 4A, each metal pattern 12g dispersed and arranged as described above is formed to have a substantially R shape by cutting a corner 12g1 that becomes a square edge portion in a plan view. Form an approximately octagonal shape. Further, as shown in FIG. 5 (a), a substantially trapezoidal shape in a longitudinal sectional view, that is, a taper 12g4 is formed on the entire circumference in the height direction of the metal pattern 12g from the top 12g2 to the bottom 12g3, and the bottom 12g3 is a substrate made of ceramics. 11 is joined to the surface with solder.

  One LED chip 13 is mounted on the substantially central portion of the top 12g2 surface of each metal pattern 12g configured as described above, and a total of 20 LED chips 13 are arranged on the surface of the substrate 11 in a matrix. The light emitting module 10 which consists of a DCB board | substrate whose outer shape which makes a rectangle is comprised.

  The DCB substrate has a feature that a metal pattern made of a copper plate for forming a wiring pattern can be formed thick. For this reason, in the portion without the metal pattern, in FIG. 5, a portion becomes a relatively deep groove, and as shown in FIG. 5B, a part of the light emitted from the LED chip is easily taken into the groove.

  On the other hand, according to the above configuration, since the taper 12g4 is formed on the entire circumference in the height direction of the metal pattern 12g, a part of the light that has been difficult to extract is formed by the taper 12g4 as shown in FIG. The light is reflected toward the light emission direction (upward in FIG. 5A) and can be effectively taken out without being taken into the groove. This eliminates optical loss and improves efficiency.

  Further, the metal pattern 12g has a configuration in which the corner 12g1 that is a square edge portion in a plan view is formed in a substantially R shape, so that sharp corners are eliminated and the electrolytic concentration is difficult. As a result, it is possible to prevent the occurrence of a migration phenomenon due to a metal such as nickel or silver plated on the surface of the metal pattern 12g to prevent oxidation, and there is no possibility that the insulation resistance between the metal patterns 12g is lowered, which is safe. A light emitting module can be provided. Moreover, since the corner 12g1 is formed in a substantially R shape, the distance between the adjacent metal patterns 12g can be increased, and reliable electrical insulation can be achieved.

  The metal pattern 12g having the above configuration is configured by means for bonding a copper plate to the substrate, but may be configured by etching. In this case, by etching the thick copper layer, which is a feature of the DCB substrate, the etching surface does not become vertical but forms a mountain shape, and a taper is automatically formed on the entire circumference in the height direction of the metal pattern 12g. You may make it reflect a part of light using this taper.

  3 to 5 showing the modified examples, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In this embodiment, the means for solving the problems / objects and problems of the present invention are the same as in the first embodiment, and the metal pattern is further distributed to improve the strength of the light emitting module made of the DCB substrate, and the warp of the substrate. This is intended to further prevent this.

  As shown in FIG. 6, in the light emitting module 10 of this embodiment, a part of the metal pattern 12 made of a copper plate provided on the surface of the ceramic substrate 11 is provided on the outer peripheral portion of the substrate 11. That is, the left and right metal patterns 12a and 12b have a length that straddles each of the metal patterns 12a and 12b on the side facing each other in common, the side positioned vertically in FIG. 6A, and the longitudinal direction of the substrate 11 The metal patterns 12c and 12d having an elongated shape are disposed adjacent to each other with a predetermined interval for electrical insulation between the metal patterns 12a and 12b, and bonded to the substrate surface by solder. The surface of each metal pattern 12c, 12d is also plated with nickel (Ni) or the like to prevent oxidation.

  The long metal patterns 12 c and 12 d act as follows by being provided on the outer peripheral portion of the substrate 11. In other words, since the long metal patterns 12c and 12d are provided along the longitudinal direction of the substrate 11, it is possible to further reduce the warpage of the substrate itself.

  Further, when the substrate 11 made of ceramic is fixed to the case body or the like by screwing, the edge portions of the metal patterns 12a and 12b close to the substrate end surface due to the influence of the warp on the case body side or the flatness of the surface, FIG. (A) Stress concentrates on part c in (b) and cracks are likely to occur.

  According to the present embodiment, since the long metal patterns 12c and 12d serving as the reinforcing frames are provided in this portion, local stress can be dispersed, and the metal patterns 12a and 12b can be dispersed. Generation of cracks at the edge portion can be prevented.

  Further, the outer peripheral portion of the substrate having a relatively low strength, in particular, the function of the reinforcing frame on the end surface of the substrate can be provided, and the occurrence of cracks in the outer peripheral portion can be prevented. Further, since the long metal patterns 12c and 12d are arranged using the dead space on the substrate 11, it is not necessary to enlarge the substrate for installing the reinforcing frame, and the module can be made smaller and thinner. Can be achieved.

  Further, in this embodiment, a part of the metal pattern 12 provided on the surface of the substrate 11 is provided around the mounting hole 11a for screw fastening. That is, four screw fastening mounting holes 11a formed at the four corners of the substrate 11 made of rectangular ceramics, and the metal pattern 12e so as to surround the periphery of each hole, the adjacent metal patterns 12a, 12b. , 12c, and 12d so as to have a predetermined interval for electrical insulation, and are joined to the substrate surface by soldering. Similarly, the surface of each metal pattern 12e is plated with nickel (Ni) or the like for preventing oxidation.

  The metal pattern 12e acts as follows by being provided so as to surround the periphery of the mounting hole 11a. That is, when the substrate 11 made of ceramics is fastened to the case body or the like by fastening screws, stress is locally generated at the screw fastening portions, and cracks are likely to occur.

  According to the present embodiment, the metal pattern 12e serving as the reinforcing frame is provided in this portion, so that the metal pattern 12e serves as the reinforcing frame, and the stress applied locally can be dispersed. Generation of cracks in the screw tightening portion can be prevented. In addition, the reinforcing frame acts around the mounting hole whose strength is relatively weak, and cracks around the mounting hole can be prevented.

  In the present embodiment, a metal pattern 12 f constituting a pair of terminal portions is provided on the surface of the substrate 11. That is, the metal pattern 12f that forms a substantially square terminal portion on the short side of the substrate 11 made of rectangular ceramics is electrically insulated from the adjacent metal patterns 12a, 12b, 12c, 12d, and 12e. It arrange | positions so that it may have a predetermined space | interval, and it joins to the board | substrate surface with solder. Similarly, the surface of each metal pattern 12f is plated with nickel (Ni) or the like for preventing oxidation.

  The metal patterns 12c and 12d forming the reinforcing frame on the outer peripheral portion of the substrate, the metal pattern 12e forming the reinforcing frame of the mounting hole 11a, and the metal pattern 12f forming the terminal portion are the left and right metal patterns for mounting the LED chip 13. Similarly to 12a and 12b, the plate is made of copper having a thickness of about 0.25 mm. In addition, since the left and right metal patterns 12a and 12b are simultaneously joined to the surface of the substrate 11 made of ceramics by solder, the manufacturability is also improved.

  In addition, similar to the left and right metal patterns 12a and 12b, these metal patterns are plated with a metal such as nickel, silver, or gold so that the light emitted from the LED chip can be effectively used. The light can be reflected and the efficiency can be further improved by reducing optical loss.

  Further, since the ceramic substrate 11 is reinforced, the thickness of the ceramic can be made thinner, and the heat of the LED chip can be effectively transferred to the metal member 14 on the back side, and the cost can be reduced. It is possible to provide a particularly advantageous light emitting module.

  As described above, according to the present embodiment, by forming the reinforcing frame by dispersing and arranging the metal patterns, it is possible to reinforce the periphery of the substrate and the periphery of the mounting hole, which are relatively weak, and cracks in the substrate These distributed reinforcing frames can adjust the volume ratio of the metal member on the back surface of the substrate with respect to the metal pattern on the substrate surface to 50% or more, and further warp the substrate itself. A light-emitting module that can be prevented can be provided.

 That is, by increasing the metal pattern on the substrate surface, the difference in volume ratio with the metal member on the back surface of the substrate is reduced, and warpage due to the difference in volume ratio can be prevented. For example, this is a configuration in which a reinforcing frame or the like is not provided, and the front-side metal pattern is suitable when the volume ratio is smaller than that of the back-side metal member. On the other hand, for example, when a reinforcement frame or the like is provided, and the front side metal pattern is larger in volume ratio than the back side metal member, if the reinforcement frame or the like is provided, the front side volume increases. As a result, the volume ratio of the metal member on the back side becomes too large, which may not be suitable. However, in this case, it is only necessary to increase the thickness and the arrangement area of the metal member on the back side, and in particular, it is preferable to increase the arrangement area of the metal member on the back side because the heat dissipation effect of the ceramic substrate can be further enhanced. .

  In this embodiment, the metal pattern 12f constituting the terminal portion is also provided, and the area of the metal member 14 on the back surface of the substrate is adjusted to be large (the thickness is about 0.2 mm as in the first embodiment). Thus, the volume ratio could be about 95%, and the volume ratio could be made closer to 100%. Accordingly, it is possible to provide the light emitting module 10 that can reduce the difference in heat capacity between the front and back surfaces of the substrate 11 as much as possible, and can further prevent the warpage caused by the heat of the substrate 11 using ceramics. it can. At the same time, according to the present embodiment, the warp of the substrate can be further prevented by providing the long metal patterns 12c and 12d along the longitudinal direction of the substrate 11.

  In FIG. 6 showing the present embodiment, the same parts as those in FIGS. 1 to 5 of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. In addition, other configurations, functions, effects, and modifications in the present embodiment are the same as those in the first embodiment.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Light emitting module 11 Board | substrate 11a Mounting hole 12 Metal pattern 13 Semiconductor light emitting element 14 Metal member 20 Illuminating device 21 Appliance main body 22 Lighting device

Claims (4)

A substrate made of ceramics;
A metal pattern distributed on the surface of the substrate;
A semiconductor light emitting device mounted on the surface of the metal pattern;
A metal member provided on the back surface of the substrate and thinner than the thickness of the metal pattern;
And the volume ratio of the metal member on the back surface of the substrate to the metal pattern on the surface of the substrate is 50% or more. The light emitting module according to claim 1, wherein a part of the metal pattern provided on the surface of the substrate is provided in a long shape on the outer peripheral portion of the substrate. 3. The light emitting module according to claim 1, wherein the substrate has a mounting hole for screw tightening, and a part of the metal pattern provided on the surface is provided around the mounting hole. A light emitting module according to any one of claims 1 to 3;
An instrument body with a light emitting module;
A lighting device for lighting the light emitting module;
An illumination device comprising:

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