JP2011134934A - Light emitting module, and lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting module and a lighting device which have improved light emission efficiencies and have lives prevented from being shortened. <P>SOLUTION: The light emitting module 10 includes: a plurality of upper and lower electrode type solid light emitting elements 11; electrode layers 12 to which lower electrodes of the solid light emitting elements are die-bonded and which have surface sides made of a material having lower reflectivity than silver; a substrate 13 formed in such a way that a surface where the plurality of solid light emitting elements and the electrode layers are mounted has a high reflectivity; bonding wires 14 for connecting upper electrodes of the solid light emitting elements to the electrode layers; and a sealing part 15 for sealing the solid light emitting elements mounted on the substrate and the bonding wires, wherein the area of each of the electrode layers is equal to or less than twice as large as that of a light emitting surface of the solid light emitting element. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a light emitting module and a lighting device using a solid 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, how to improve the light emission efficiency of the light emitting diode is an important issue. For example, Patent Document 1 shows a light-emitting diode device in which a bottom silver-plated reflective layer is provided on the bottom surface of a light-emitting diode chip. In particular, paragraph [0040] shows that a bottom silver-plated reflective layer is a light-emitting diode chip. It has been shown that the luminous flux that can be extracted to the outside can be improved by, for example, about 20% because the reflectivity is high over almost the entire visible light range from the short wavelength range to the long wavelength range.

JP 2007-180430 A

  However, as shown in paragraph [0027], the light emitting diode device of Patent Document 1 has silver plating on a pair of circuit patterns on the cathode side and the anode side, that is, on the electrodes, in order to improve the light emission efficiency. Is formed. For this reason, there arises a problem that the reflectance is lowered due to the discoloration of silver plating and the light emission efficiency is lowered. Furthermore, there are concerns that the life is affected in many respects, such as a reduction in life due to deterioration of silver plating, occurrence of ion migration, and reduction in bonding strength between the gold wire and silver plating.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a light emitting module and a lighting device that can improve the light emission efficiency and prevent the lifetime from being reduced. .

  The invention of the light emitting module according to claim 1 is an electrode layer formed by die-bonding a plurality of upper and lower electrode type solid state light emitting elements; and a lower electrode of the solid state light emitting element, and having a surface side made of a material having a lower reflectance than silver. A substrate formed so that the reflectance of the surface on which the plurality of solid-state light emitting elements and the electrode layer are mounted is increased; a bonding wire for connecting the upper electrode of the solid light-emitting element to the electrode layer; and a solid mounted on the substrate A sealing portion for sealing the light emitting element and the bonding wire, and the area of the electrode layer is set to be not more than twice that of the light emitting surface of the solid light emitting element. According to the present invention, by using a plurality of upper and lower electrode type solid state light emitting devices and making the area of the electrode layer less than or equal to twice the light emitting surface of the solid state light emitting device, it is possible to improve the luminous efficiency and improve the lifetime. It is possible to prevent the decrease.

  In the present invention, the light emitting module is applied to a relatively large lighting device such as an office or the like that performs general lighting from the ceiling or the like, but is a small lighting device for general lighting such as a house, It may be applied to a lamp with a cap using a solid light emitting element such as a light emitting diode as a light source. The light emitting module is preferably configured to emit white light. However, depending on the use of the lighting device, the light emitting module may be configured to be red, blue, green, or a combination of various colors.

  The solid-state light-emitting element is preferably composed of a light-emitting diode chip made of a gallium nitride (GaN) -based semiconductor that emits blue light. However, a light-emitting element using a semiconductor laser, an organic EL, or the like as a light source is acceptable. The In the solid-state light emitting device, it is preferable to form a reflective layer by plating a metal having a high reflectance, for example, silver (Ag), on the entire bottom surface of the light emitting layer. There may be a portion that is not provided in the portion.

  The material of the reflective layer may be made of metal such as gold (Au), aluminum (Al), or nickel (Ni) instead of silver. In addition to plating, for example, these metals may be formed by etching or may be formed by coating.

  The substrate is a member for mounting a plurality of solid state light emitting elements as a light source, and is preferably composed of ceramics having high reflectivity, but aluminum (Al), nickel (Ni), copper (Cu) Or glass epoxy may be used. The shape is preferably a square or a rectangle to form a surface module necessary for arranging a plurality of, for example, light emitting diode chips with a predetermined interval. In order to obtain the desired light distribution characteristics, it may be a polygonal shape such as an octagon with four corners cut, a circular shape, an elliptical shape, etc., or a long line shape that constitutes a line module. All shapes are acceptable.

  The lower electrode of the solid light emitting element is die-bonded, and the electrode layer formed on the surface side with a material having a lower reflectance than silver forms the wiring pattern of the solid light emitting element, and the material is a metal having good conductivity. For example, it is preferable to be composed of gold (Au). However, copper (Cu), aluminum (Al), nickel (Ni), and other metals having lower reflectivity than silver and good conductivity Is acceptable.

  The electrode layer may be configured as a thin metal layer formed by plating, etching or the like with respect to the substrate, or a thin metal plate may be bonded to the substrate by soldering means such as solder. . In addition, the electrode layer made of these metals is preferably die-bonded so that the lower electrode side of the solid light-emitting element is mounted on the surface and is fixed with a conductive adhesive such as silver paste. The solid-state light-emitting element may be directly mounted on the substrate, and an electrode layer may be formed adjacent to and separated from the solid-state light-emitting element and connected by a bonding wire, and a specific means for die bonding Is not limited to these specific ones.

  The electrode layer is preferably arranged in a matrix form with a predetermined interval on the substrate with these metals, and a solid light emitting element is preferably mounted and mounted on the electrode layer. Alternatively, a part or the whole may be arranged in a regular order, such as a radial pattern, or may be randomly arranged. The solid light emitting device is preferably mounted on the surface of the substrate using COB (Chip on Board) technology, but may be mounted using a SMD (Surface Mount Device) type. .

  The sealing part that seals the solid-state light emitting element and the bonding wire has a yellow phosphor layer by adding, for example, a yellow phosphor to a thermosetting synthetic resin such as a translucent silicone resin or epoxy resin. Although it is preferable to comprise, it may be comprised with the transparent synthetic resin or glass which does not add a fluorescent substance.

  In addition, the area of the electrode layer is configured to be less than twice that of the light emitting surface of the solid state light emitting device, but it does not exclude a ratio that is strictly more than twice, and suppresses a decrease in luminous efficiency due to the electrode layer. On the other hand, magnifications in the vicinity of more than 2 times that can ensure the heat dissipation of the solid state light emitting device are allowed. The area of the electrode layer is preferably about 1.54 times the light emitting surface of the light emitting layer. As a result, the area of the electrode layer is slightly larger than the area of the light emitting surface, it is possible to secure a space for connecting the bonding wire to the electrode layer, increase the bonding strength between the bonding wire and the electrode layer, and dissipate heat. It becomes possible to improve the property.

  In the present invention, the “surface side” means a surface on the light emitting part side in the light emitting module.

  The invention of the lighting device according to claim 2 comprises the light-emitting module according to claim 1, a fixture main body in which the light-emitting module is disposed, and a lighting device for lighting the light-emitting module. . According to the present invention, by using the light emitting module according to the first aspect, a lighting device that can improve luminous efficiency and prevent a decrease in lifetime is configured.

  In the present invention, the lighting device can be used for housing by using one or several light emitting modules even if a plurality of light emitting modules are combined to form a relatively long large lighting fixture for facilities / businesses such as a long office. A lamp with a base for general illumination or a small illumination device may be configured.

  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 light control and a color control function.

  According to the first aspect of the present invention, by using a plurality of upper and lower electrode type solid light emitting elements and making the area of the electrode layer less than twice the light emitting surface of the solid light emitting element, it is possible to suppress a decrease in light emission efficiency. In addition, it is possible to provide a light emitting module capable of preventing a decrease in life due to a decrease in heat dissipation.

  According to the invention described in claim 2, by using the light emitting module according to claim 1, it is possible to provide an illuminating device capable of improving the light emission efficiency and preventing the lifetime from decreasing. .

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which expands and shows typically the light emitting module which concerns on embodiment of this invention, (a) is sectional drawing which notches some, and (b) is a cross section which shows the reflective state of light in (a) figure Figure. Similarly, it is a figure which expands and shows a light emitting module typically, (a) is a front view and (b) is a sectional view which meets a bb line of (a) figure. The result of having experimented the relationship between the electrode pattern width in a light emitting module and thermal resistance similarly, (a) is the front view and side view which show the relationship between the electrode pattern used for experiment, and a light emission surface, (b) is electrode pattern width. And graph showing the relationship between thermal resistance. Similarly, a graph for analyzing the relationship between the electrode pattern width and the thermal resistance in the light emitting module, (a) is a graph equivalent to FIG. 3 (b), (b) is a graph obtained by differentiating the graph of FIG. (C) is a graph obtained by further differentiating FIG. The lighting device which similarly uses a light emitting module is shown, (a) is a longitudinal cross-sectional view, (b) is a bottom 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, the light emitting module 10 of this embodiment includes a solid light emitting element 11, an electrode layer 12 for die bonding the solid light emitting element, a plurality of solid light emitting elements and a substrate 13 for mounting the electrode layer, and a solid light emitting element. It comprises a bonding wire 14 connected to the electrode layer, a solid-state light emitting element, and a sealing portion 15 for sealing the bonding wire.

  The solid-state light emitting element 11 is constituted by a light emitting diode chip (hereinafter referred to as “LED chip”), and the LED chip 11 is provided with a plurality of LED chips having the same performance. It consists of a blue LED chip with high brightness and high output. The LED chip 11 has a light emitting layer 11a in the upper part, and a reflective layer 11b for reflecting light emitted downward from the light emitting layer is formed in the lower part of the light emitting layer. The reflective layer is formed by plating a metal having high reflectance, in this embodiment, pure silver (Ag) over the entire lower surface of the light emitting layer 11a. The silver constituting the reflective layer 11b is not limited to pure silver, but may be a material added with a trace amount of metal such as platinum (Pt) or lead (Pb). The reflective layer is formed with a thickness of about 3 μm. In the drawing, 11c is a conductive layer made of copper (Cu) formed over the entire lower surface of the reflective layer 11b.

  The LED chip 11 is configured as an upper and lower electrode type in which the upper surface of the light emitting layer 11a is the upper electrode 11d on the cathode side, and the lower surface of the reflective layer 11b is the lower electrode 11e on the anode side. The chip is configured as a large-capacity chip with a rated power consumption of 1.0 to 2.5 W with a chip angle of about 100 mm and a chip angle of about 1 mm.

  As shown in FIG. 2 (a), the plurality of LED chips 11 configured as described above are arranged in a matrix on the surface of the substrate 13, with 5 vertically and 5 horizontally having substantially equal intervals. Arranged and mounted with high density. The substrate 13 is configured to be a substantially square flat plate made of white ceramics having high reflectivity so as to have thermal conductivity and high reflectivity on the surface (a metal having high reflectivity such as Ni or the like). May be plated). An electrode layer 12 constituting a wiring pattern for connecting a plurality of LED chips 11 is formed on the surface of the substrate 13.

  The electrode layer 12 is made of a metal having a lower reflectance than silver on the surface side and having conductivity, in this embodiment, gold (Au) so that a wiring pattern is formed in advance on the surface of the substrate 13 made of ceramics. It forms by plating on the formed conductive layer 12a made of copper (Cu). The gold constituting the electrode layer 12 is not limited to pure gold and may be 18 gold or the like.

  As shown in FIG. 2 (a), the electrode layer 12 has a total of 25 electrode layers on the surface of the substrate 13, 5 in the vertical direction and 5 in the horizontal direction. As is done, they are arranged in a matrix with substantially equal intervals s. The electrode layer 12 is formed in a substantially square shape having a thickness of about 35 to 250 μm and a side length of about 1.4 (√2) mm square. The conductive layer 12a is formed by bonding a thin copper plate forming a wiring pattern to the surface of the substrate 13 with solder.

  The LED chip is mounted on the substrate 13 on which the electrode layer 12 is formed as described above by the COB technique. That is, one LED chip 11 is mounted on the surface of 25 electrode layers 12 with the conductive layer 11c of the lower electrode 11e facing the surface of the electrode layer 12, and a conductive adhesive. In this embodiment, the lower electrode 11e of the LED chip 11 is die-bonded to the electrode layer 12 by being fixed with a thermosetting silver paste. At this time, the square LED chip 11 is fixed to the square electrode layer 12 with a slight shift parallel to one direction (downward in FIG. 2A). As a result, a slightly wider space is formed on one side above the electrode layer 12, and a connection space 12 b for the bonding wire 14 is secured.

  The bonding wire 14 is made of gold wire and bonded so as to sequentially connect the upper electrode 11d of each LED chip 11 and the connection space 12b of the electrode layer 12 of the LED chip 11 adjacent in the vertical direction in FIG. I do. At this time, the electrode layer 12 is made of the same gold as the bonding wire 14 made of a gold wire, and the bonding strength can be increased. As described above, the upper electrode 11 d on the cathode side of each LED chip 11 is connected to the lower electrode 11 e on the anode side of each adjacent LED chip 11 via the electrode layer 12. The end on the anode side is connected to the common terminal 12c on the anode side, and the end on the cathode side is connected to the common terminal 12d on the cathode side. As a result, 25 LED chips 11 connected in series are mounted on the surface of the substrate 13. The common terminals 12c and 12d on the anode side and the cathode side are formed by plating gold (Au) on the conductive layer 12a on the surface of the substrate 13 made of ceramics, like the electrode layer 12.

  The sealing portion 15 is made of a translucent resin, in this embodiment, a yellow phosphor added to a silicone resin, and this covers the LED chip 11 mounted on the substrate and the bonding wire 14 which is a charging portion. Fill and seal. Thereby, the sealing unit 15 transmits the blue light emitted from the light emitting layer 11a of the blue LED chip 11, and excites the yellow phosphor by the blue light to convert it into yellow light, and transmits the transmitted blue light and yellow light. The light is mixed so that white light is emitted.

  At this time, as shown in FIG. 1B, the white light emitted from the light emitting layer 11a is emitted upward along the optical axis xx direction and also emitted downward. The light a emitted downward is reflected by the reflective layer 11b and emitted upward. In particular, the reflective layer 11b is made of silver having a high reflectance over the entire visible light region, and can improve the light flux that can be extracted to the outside.

  At the same time, the light b emitted obliquely downward from the side surface of the light emitting layer 11a of the LED chip 11 is formed between the surface of the electrode layer 12 made of gold and the LED chips 11 arranged in a matrix in the interval s. Then, the light is reflected on the surface of the white ceramic substrate 13 and emitted upward.

  As described above, the flat light emitting module 10 having a substantially square shape in which the upper and lower electrode type 25 LED chips 11 having the reflective layer 11b below the light emitting layer 11a are mounted in a matrix is configured. The light emitting module 10 has a reflective layer 11b made of silver formed under the light emitting layer 11a, and is provided so that silver is not exposed to the outside of the LED chip 11, so that the discoloration of silver can be prevented. A decrease in luminous efficiency can be prevented. Furthermore, deterioration of silver plating can be prevented. Furthermore, since the electrode layer 12 is made of gold, it is possible to prevent the occurrence of ion migration due to conventional silver and the decrease in strength due to the bonding between the gold wire and silver.

  Further, the length of one side of the light emitting surface of the light emitting layer 11a of the LED chip 11 is about 1 mm and the length of one side of the electrode layer 12 is about 1.4 (√2) mm, in other words, each electrode is a square. The area of the layer 12 is formed less than twice the area of the light emitting surface of the LED chip. As a result, as shown in FIG. 1A, the exposed area (reflective area) of the electrode layer 12 made of gold, which has a reflectance lower than silver and easily absorbs blue light, can be reduced as much as possible. A decrease can be prevented.

  At the same time, due to the spacing s between the LED chips 11 formed by reducing the area of the electrode layer 12, the light b emitted obliquely downward from the side surface of the light emitting layer 11a of the LED chip 11 is partly made of silver. Although most of the light is reflected on the surface of the electrode layer 12 made of gold having a low reflectance, most of the light reaches the surface of the white ceramic substrate 13 having a high reflectance through the interval s and is effectively reflected.

  In addition, the electrode layer 12 made of gold, which has a lower reflectance than silver and easily absorbs blue light, prevents the decrease in light emission efficiency by reducing the area as much as possible, and at the same time dissipates the heat of the LED chip 11 to the outside. Therefore, the function of the heat dissipation part must be demonstrated. For this reason, the electrode layer 12 must be made as small as possible from the viewpoint of preventing a decrease in luminous efficiency. On the other hand, from the aspect of heat dissipation, it is necessary to make it as large as possible, and it is necessary to select a predetermined area for satisfying this “reciprocal condition”.

  According to the experiment, in the light emitting module 10 having the above-described configuration, the length of one side of the electrode layer 12 is about 1.4 (√2) times or less and the area ratio is 2 times or less with respect to a 1 mm square LED chip. It was confirmed that the above-mentioned “conflicting conditions” can be satisfied by setting to.

  3B, the electrode pattern width (length of one side of the electrode layer 12) in the electrode layer 12 having a substantially square shape shown in FIG. 3A is increased from 0.9 mm to 2 mm by 0.1 mm. In the graph, the vertical scale is the thermal resistance value (Rjb), and the horizontal scale is the electrode pattern width (mm). Then, a graph (FIG. 4B) created by differentiating and creating a graph equivalent to this graph (FIG. 4A) is created, and a graph created by further differentiating the graph of FIG. 4B (FIG. 4B). As shown in FIG. 4 (c), the rate of change is small in the vicinity of the electrode pattern width of about 1.4 mm, the electrode pattern width for making the electrode layer 12 as small as possible and ensuring proper heat dissipation. The limit value of was able to be obtained.

  That is, when the function is differentiated twice, a change rate function (f ″ (x)) is obtained. If f ″ (x) is 0, the rate of change is constant, that is, a straight line. Conversely, if f ″ (x) is large, it increases exponentially. In the domain where the function of f ″ (x) is 0.9 <= x <= 1.7, f ″ (x) is minimum (change rate is minimum) because x≈1.4. This was determined as the upper limit (limit value).

  Further, by making the area of the electrode layer 12 approximately 1.54 times the area of the light emitting surface of the light emitting layer 11a, the area of the electrode layer 12 becomes slightly larger than the area of the light emitting surface, and a bonding wire is connected to the electrode layer. This makes it possible to secure the space 12b for increasing the bonding strength between the bonding wire and the electrode layer, and at the same time improve the heat dissipation.

  As described above, the light emitting module 10 is configured that can ensure the heat dissipation of the LED chip 11 while preventing the light emission efficiency from decreasing and can prevent the lifetime from decreasing. As shown in FIG. 5, 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. The lighting device 22 may be configured separately from the instrument main body 21.

  As shown in FIG. 5A, 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 an opening side of one end portion (downward in FIG. 5A) inside the cylindrical body. The partition plate 21a is a support portion for supporting the light emitting module 10 on the instrument body, and has a flat surface (a lower surface in FIG. 5A) serving as a heat dissipation portion.

 The light emitting module 10 is placed on the flat surface of the partition plate 21a, and is fastened to the partition plate 21a with screws around four places using mounting holes provided in the substrate 13, and the back surface of the substrate 13 is made of aluminum. It is made to adhere firmly and fixed to the partition plate 21a.

 A reflector 23 is provided on the surface side of the light emitting module 10 fixed to the partition plate 21a as described above so as to surround each LED chip 11. The reflector 23 is made of a white synthetic resin having light resistance, heat resistance, and electrical insulation, for example, PBT (polybutylene terephthalate) and the like, and 25 LED chips 11 mounted on the substrate 13 of the light emitting module 10. A circular light inlet 23a having a diameter that can surround the LED chip 11 and a "mortar-shaped" reflecting surface 23b that forms a rotating paraboloid that faces each other so as to surround each LED chip 11 are 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 of each LED chip 11 in the light emitting module 10, converts an AC voltage 100 V into a DC voltage 24 V, and supplies a constant current to each LED chip 11. It is configured to supply 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 instrument main 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 11 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 light emitting layer 11a of the LED chip 11 is emitted downward and upward in FIG. 5A along the optical axis xx direction. As shown in FIG. 1B, the light a emitted upward is reflected by the reflective layer 11b and emitted downward. In addition, the radiation | emission direction of the light of the state in FIG.1 (b) and the state in Fig.5 (a) installed in the ceiling is upside down. In particular, the reflective layer 11b is made of silver having a high reflectance over the entire visible light region, so that the light flux that can be extracted to the outside can be improved, and the luminous efficiency can be improved.

  Further, a part of the light b emitted obliquely upward from the side surface of the light emitting layer 11a is reflected by the surface of the electrode layer 12 made of gold having a reflectance lower than that of silver, but most of the light has an interval s. And reaches the surface of the white ceramic substrate 13 formed so as to have a high reflectance, and is effectively reflected and emitted downward. With these actions, a decrease in light emission efficiency can be prevented, and illumination with little light loss can be performed.

  Further, the heat generated from each LED chip 11 is transmitted from the electrode layer 12 to the substrate 13 and further from the partition plate 21a of the instrument body to the instrument body 21 and radiated to the outside. At this time, the electrode layer 12 is made of gold having good thermal conductivity, and the area of the electrode layer 12 is formed to be not more than twice the area of the light emitting surface of the light emitting layer 11a. Since the resistor is configured to have an appropriate value, it can be effectively transmitted to the substrate 13. Further, the substrate 13 is also made of ceramic having thermal conductivity, and the instrument body is also made of aluminum having good thermal conductivity and is transmitted to the side wall of the main body having a large surface area, so that heat can be radiated more effectively to the outside. .

  By these heat dissipation actions, a decrease in light conversion efficiency in each LED chip 11 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, since the light emitting module 10 has the reflective layer 11b made of silver formed under the light emitting layer 11a, the light a emitted downward from the light emitting layer 11a is reflected by the reflective layer 11b. And emitted upward. In particular, the reflective layer 11b is made of silver having a high reflectivity over the entire visible light region, and can improve the luminous flux that can be extracted to the outside and improve the luminous efficiency.

  Further, the length of one side of the light emitting surface of the light emitting layer 11a of the LED chip 11 is about 1 mm and the length of one side of the electrode layer 12 is about 1.4 (√2) mm, in other words, each electrode is a square. Since the area of the layer 12 is less than twice the area of the light emitting surface of the LED chip 11, the exposed area (reflective area) of the electrode layer 12 made of gold, which has a lower reflectance than silver and easily absorbs blue light. It can be made as small as possible, and a decrease in luminous efficiency can be prevented. At the same time, the light b emitted obliquely downward from the side surface of the light emitting layer 11a of the LED chip 11 due to the spacing s between the LED chips 11 formed by reducing the area of the electrode layer 12 passes through the spacing s. It reaches the surface of the white ceramic substrate 13 formed so as to have a high reflectance and is effectively reflected, thereby further preventing a decrease in luminous efficiency.

  Further, by forming the electrode layer 12 so that the area of the electrode layer 12 is not more than twice the area of the light emitting surface of the LED chip 11, the thermal resistance of the electrode layer 12 can be configured to have an appropriate value. The heat generated from the LED chip 11 can be effectively transferred to the substrate 13, the decrease in light conversion efficiency in the LED chip 11 can be suppressed, and the decrease in luminous flux can be prevented, and at the same time the life of the LED chip can be extended. I get out.

  In addition, the light emitting module 10 is provided so that the silver constituting the reflective layer 11b is not exposed to the outside of the LED chip 11, and the discoloration of the silver can be prevented, so that the light emission efficiency can be prevented from being lowered. At the same time, it is possible to prevent a decrease in life due to deterioration of silver plating.

  In addition, since the electrode layer 12 is made of gold, it is possible to prevent conventional ion migration due to silver and a decrease in strength due to bonding between a gold wire and silver, thereby preventing a decrease in life.

  With the above-described actions, it is possible to provide the light emitting module 10 and the lighting device 20 that can ensure the heat dissipation of the LED chip 11 while preventing the light emission efficiency from decreasing and can prevent the lifetime from decreasing.

  In the present embodiment, the LED chip 11 and the electrode layer 12 are formed in a square shape, and the area of the electrode layer 12 is configured to be less than twice the light emitting surface of the LED chip 11. Even if the ratio is configured to be twice or less, the same effect can be obtained.

  Further, although the conductive layer made of copper is provided on the reflective layer 11b and the electrode layer 12 of the LED chip 11, it may be formed of a conductive metal such as aluminum (Al) or nickel (Ni). Further, these conductive layers may be omitted.

  Although the preferred embodiments of the present invention have been described above, 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 Solid light emitting element 12 Electrode layer 13 Board | substrate 14 Bonding wire 15 Sealing part 20 Illuminating device 21 Appliance main body 22 Lighting device

Claims (2)

A plurality of solid state light emitting devices of upper and lower electrode type;
An electrode layer formed by die-bonding the lower electrode of the solid state light emitting device and having a surface side made of a material having a lower reflectance than silver;
A substrate formed such that the reflectance of the surface on which the plurality of solid state light emitting elements and the electrode layer are mounted;
A bonding wire connecting the upper electrode of the solid state light emitting device to the electrode layer;
A sealing portion for sealing the solid state light emitting device and the bonding wire mounted on the substrate;
And the area of the electrode layer is not more than twice the light emitting surface of the solid state light emitting device. A light emitting module according to claim 1;
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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