JP5010203B2 - Light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting apparatus capable of improving heat radiation performance. <P>SOLUTION: The light-emitting apparatus is provided with an LED chip 1, and a mounting substrate 2 formed using silicon substrates 20a, 30a, 40a as a semiconductor substrate and mounted with the LED chip 1. A plurality of through-hole wirings 24 as one part of a power feed passage to the LED chip 1, and a plurality of thermal vias 26 used as a passage for radiating the heat generated from the LED chip 1, are provided to pierce in the thickness direction of the mounting substrate 2. The cross-sectional area of each of the thermal vias 26 in a cross section orthogonal to the thickness direction is larger than the cross-sectional area of each of the through-hole wirings 24, and the mounting substrate 2 has a die pad 25aa as a heat equalizing plate joined to the overall one surface of the LED chip 1 and for thermally coupling the LED chip 1 to the thermal vias 26. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a light emitting device using an LED chip (light emitting diode chip).

  Conventionally, as shown in FIG. 15, an LED chip 1 ′ and a mounting substrate (package) 2 ′ formed by using a silicon substrate 20 a ′ and mounted with the LED chip 1 ′ are mounted on the LED chip 1 ′. A light-emitting device in which a plurality of through-hole wirings 24 ′ serving as a part of a power feeding path and a plurality of thermal vias 26 ′ serving as a heat dissipation path for heat generated in the LED chip 1 ′ are penetrated in the thickness direction of the mounting substrate 2 ′. It has been proposed (see, for example, Patent Document 1).

  Here, in the light emitting device having the configuration shown in FIG. 15, each electrode (not shown) formed on the one surface side of the LED chip 1 ′ has conductors of the mounting substrate 2 ′ via Au bumps 13a ′ and 13a ′. The conductor patterns 25a ′ and 25a ′ are electrically connected to the patterns 25a ′ and 25a ′, and the conductor patterns 25a ′ and 25a ′ are respectively connected to the external connection electrodes 27a ′ and the like via a plurality of (three in the illustrated example) through-hole wirings 24 ′. 27a 'is electrically connected. Further, in this light emitting device, a heat radiating metal portion 21 ′ smaller than the chip size of the LED chip 1 ′ is formed on the surface of the mounting substrate 2 ′ facing the LED chip 1 ′. The metal portion 21 ′ is thermally coupled to the heat radiating metal portion 21 ′ via the plurality of Au bumps 13c ′, and the heat radiating metal portion 21 ′ is thermally coupled to the heat radiating pad portion 28 ′ via the plurality of thermal vias 26 ′.

In the light emitting device having the configuration shown in FIG. 15, in the formation of each through hole wiring 24 ′ and each thermal via 26 ′, the through hole for the through hole wiring 24 ′ and the thermal via 26 ′ are formed in the silicon substrate 20a ′. After forming the through holes at the same time, an insulating film (not shown) made of a silicon oxide film is formed by thermal oxidation, and then the through hole wiring 24 ′ and the thermal via 26 ′ are formed simultaneously by plating or the like. Yes.
Japanese Patent Laid-Open No. 2005-19609

  In the light emitting device having the configuration shown in FIG. 15, the conductor patterns 25a ′ and 25a ′ electrically connected to the respective electrodes of the LED chip 1 ′ are connected to the external connection electrodes 27a ′ via the through-hole wirings 24 ′ and 24 ′. , 27a ′, the planar size of the mounting substrate 2 ′ can be reduced, and the mounting area on the circuit board or the like can be reduced. However, in the light emitting device having the configuration shown in FIG. 15, the LED chip 1 ′ and the heat radiating metal portion 21 ′ are thermally coupled by the plurality of Au bumps 13 c ′, and the planar size of the heat radiating metal portion 21 ′ is obtained. Is smaller than the chip size of the LED chip 1 ′, the thermal resistance of the heat dissipation path of the heat generated in the LED chip 1 ′ is relatively large, and the number of thermal vias 26 ′ depends on the planar size of the heat radiating metal portion 21 ′. Therefore, improvement in heat dissipation has been desired.

  This invention is made | formed in view of the said reason, The objective is to provide the light-emitting device which can improve heat dissipation.

The invention of claim 1 includes an LED chip and a mounting substrate formed using a semiconductor substrate and mounted with the LED chip, and a plurality of through-hole wirings and LED chips that are part of a power feeding path to the LED chip. A light-emitting device in which a plurality of thermal vias serving as heat dissipation paths for generated heat are provided in the thickness direction of the mounting board, and the mounting board has a cross-sectional area of each thermal via in a cross section perpendicular to the thickness direction. The cross-sectional area of the hole wiring is larger, and the entire surface of the LED chip is bonded, and has a heat equalizing plate portion that thermally couples the LED chip and the plurality of thermal vias, and the LED chip is mounted on the mounting substrate. The LED mounting portion, the wall portion provided in the periphery of the region where the LED chip is mounted in the LED mounting portion, and the overhang portion protruding from the wall portion, and the overhang portion from the LED chip Release Photodetector for detecting the light, characterized in that is provided.

According to the present invention, the mounting substrate has an LED in which the cross-sectional area of each thermal via in the cross section perpendicular to the thickness direction of the mounting substrate is larger than the cross-sectional area of each through-hole wiring, and the entire surface of the LED chip is bonded. Since it has a soaking plate part that thermally couples the chip and a plurality of thermal vias, the cross-sectional area of the heat radiation path is between the LED chip and each thermal via among the heat radiation paths generated by the LED chip. Since there is no section smaller than the chip size of the chip, it is possible to reduce the thermal resistance and increase the heat dissipation, and to cut off each thermal via in the cross section perpendicular to the thickness direction of the mounting board. Since the number of thermal vias can be increased without reducing the area, the heat dissipation can be further enhanced . Further, according to the present invention, the mounting substrate protrudes from the wall portion, the LED mounting portion on which the LED chip is mounted, the wall portion provided in the peripheral portion of the LED mounting portion in the region where the LED chip is mounted, and Since the light detection element for detecting the light emitted from the LED chip is provided on the overhanging portion, the light emitted from the LED chip can be detected.

  According to a second aspect of the present invention, in the first aspect of the invention, the mounting board includes a plurality of conductor portions connected to the through-hole wirings formed around the heat equalizing plate portion. .

  According to this invention, since it becomes possible to increase the number of the thermal vias compared to the case where the LED chip and the through-hole wiring overlap in the thickness direction of the mounting substrate, the heat dissipation is improved. It becomes possible.

  In the invention of claim 1, there is an effect that it is possible to improve the heat dissipation.

(Embodiment 1)
Hereinafter, the light-emitting device of this embodiment will be described with reference to FIGS.

  In the light emitting device of this embodiment, an LED chip 1 that emits visible light (for example, red light, green light, blue light, and the like) and a storage recess 2a that stores the LED chip 1 are formed on one surface. A mounting substrate 2 on which the LED chip 1 is mounted on the inner bottom surface of 2a, a translucent member 3 fixed to the mounting substrate 2 so as to close the housing recess 2a on the one surface side of the mounting substrate 2, and a mounting A light detecting element 4 (see FIG. 3) for detecting light emitted from the LED chip 1 provided on the substrate 2 and a translucent sealing resin (for example, silicone) filled in the housing recess 2a of the mounting substrate 2 A sealing portion 5 that is made of a resin, an acrylic resin, or the like and seals the LED chip 1 and the bonding wire 14 connected to the LED chip 1. Here, the mounting substrate 2 has a hook-like protruding portion 2c protruding inward from the peripheral portion of the storage recess 2a on the one surface side, and the light detection element 4 is provided on the protruding portion 2c. Is provided. In the present embodiment, the package is constituted by the mounting substrate 2 and the translucent member 3, but the translucent member 3 is not necessarily provided, and may be appropriately provided as necessary.

  As shown in FIGS. 1 to 3, the mounting substrate 2 is disposed opposite to the rectangular plate-shaped LED mounting substrate 20 on which the LED chip 1 is mounted on one surface side and the LED mounting substrate 20 on the one surface side. The circular light extraction window 41 and the light detection element forming substrate 40 on which the light detection element 4 is formed, and the light extraction window interposed between the LED mounting substrate 20 and the light detection element formation substrate 40. The space surrounded by the LED mounting substrate 20, the intermediate layer substrate 30, and the photodetecting element forming substrate 40 is configured by the intermediate layer substrate 30 in which the rectangular opening window 31 communicating with the terminal 41 is formed. The storage recess 2a is configured. Here, the outer peripheral shapes of the LED mounting substrate 20, the intermediate layer substrate 30, and the light detection element formation substrate 40 are rectangular, and the intermediate layer substrate 30 and the light detection element formation substrate 40 have the same outer dimensions as the LED mounting substrate 20. Is formed. Further, the thickness dimension of the light detection element forming substrate 40 is set smaller than the thickness dimension of the LED mounting substrate 20 and the intermediate layer substrate 30. In the present embodiment, the LED mounting substrate 20 constitutes an LED mounting portion on which the LED chip 1 is mounted, and the intermediate layer substrate 30 and the light detection element forming substrate 40 are connected to the LED chip 1 in the LED mounting portion. The wall 2b provided in the periphery of the area to be mounted, and the portion of the photodetecting element forming substrate 40 that protrudes over the opening window 31 of the intermediate layer substrate 30 constitutes the protruding portion 2c.

  The LED mounting substrate 20, the intermediate layer substrate 30, and the light detection element formation substrate 40 described above are formed using silicon substrates 20 a, 30 a, and 40 a each having an n-type conductivity and a (100) plane main surface. is there. Here, in the present embodiment, each of the silicon substrates 20a, 30a, and 40a constitutes a semiconductor substrate. In short, in the present embodiment, the mounting substrate 2 is formed using three semiconductor substrates.

  In the present embodiment, the inner side surface of the intermediate layer substrate 30 is constituted by a (111) plane formed by anisotropic etching using an alkaline solution (for example, TMAH solution, KOH solution, etc.) ( That is, the intermediate layer substrate 30 gradually increases as the opening area of the opening window 31 increases from the LED mounting substrate 20), and forms a mirror 2 d that reflects the light emitted from the LED chip 1 forward. Yes. In short, in the present embodiment, the intermediate layer substrate 30 also serves as a frame-like reflector that reflects light emitted from the LED chip 1 to the side.

  As shown in FIGS. 4 and 5, the LED mounting substrate 20 is electrically connected to each of both electrodes of the LED chip 1 on one surface side (left surface side in FIG. 4C) of the silicon substrate 20 a. Two conductor patterns 25a and 25a are formed, and two conductor patterns 25b that are electrically connected to the light detection element 4 through two through-hole wirings 34 and 34, which will be described later, formed on the intermediate layer substrate 30. , 25b, and four external connection electrodes 27a, 27a, 27b formed on the other surface side (the right side in FIG. 4C) of each conductor pattern 25a, 25a, 25b, 25b and the silicon substrate 20a. 27b and 27b are electrically connected through the through-hole wiring 24, respectively. The LED mounting substrate 20 is also formed with a bonding metal layer 29 for bonding to the intermediate layer substrate 30 on the one surface side of the silicon substrate 20a.

  The LED chip 1 in the present embodiment is a visible light LED chip in which a conductive substrate is used as a crystal growth substrate and electrodes (not shown) are formed on both surfaces in the thickness direction. Therefore, the LED mounting substrate 20 has one of the two conductor patterns 25a, 25a to which the LED chip 1 is electrically connected, the rectangular die pad portion 25aa to which the LED chip 1 is die-bonded. And a lead-out wiring portion 25ab that is continuously formed integrally with the die pad portion 25aa and serves as a connection portion with the through-hole wiring 24. In short, the LED chip 1 is die-bonded to the die pad portion 25aa of the one conductor pattern 25a, and the electrode on the die pad portion 25aa side is joined to and electrically connected to the die pad portion 25aa, and the electrode on the light extraction surface side. Is electrically connected to the other conductor pattern 25 a via the bonding wire 14. Here, in the present embodiment, the outer peripheral shape in plan view of the LED chip 1 and the die pad portion 25aa is rectangular (in the illustrated example, a square shape), and the planar size of the die pad portion 25aa is larger than the planar size of the LED chip 1. Set slightly larger.

  The LED mounting substrate 20 has a rectangular heat radiation pad portion 28 made of a metal material having a higher thermal conductivity than the silicon substrate 20a on the other surface side of the silicon substrate 20a. The die pad portion 25aa And the heat dissipating pad portion 28 through a plurality of (in this embodiment, nine) cylindrical thermal vias 26 made of a metal material (for example, Cu) having a thermal conductivity higher than that of the silicon substrate 20a. The heat generated in the LED chip 1 is dissipated through the thermal vias 26 and the heat dissipating pad portion 28.

  By the way, the LED mounting substrate 20 has, in the silicon substrate 20a, four through holes 22a in which the above-described four through-hole wirings 24 are formed inside, and each of the nine thermal vias 26 in the inside. Nine through holes 22b are provided in the thickness direction, and an insulating film made of a thermal oxide film (silicon oxide film) straddling the one surface and the other surface of the silicon substrate 20a and the inner surfaces of the through holes 22a and 22b. 23, each conductor pattern 25a, 25a, 25b, 25b, bonding metal layer 29, each external connection electrode 27a, 27a, 27b, 27b, heat radiation pad 28, each through-hole wiring 24, and each The thermal via 26 is electrically insulated from the silicon substrate 20a. Here, in this embodiment, the opening shape of the through hole 22b for each thermal via 26 and the opening shape of the through hole 22a for each through hole wiring 24 are circular, but the through hole 22b for the thermal via 26 has a circular shape. The inner diameter dimension is set larger than the inner diameter of the through hole 22a for the through hole wiring 24, and the cross sectional area of the thermal via 26 in the cross section perpendicular to the thickness direction of the silicon substrate 20a is larger than the cross sectional area of the through hole wiring 24. It has become.

  The conductor patterns 25a, 25a, 25b, and 25b, the bonding metal layer 29, the external connection electrodes 27a, 27a, 27b, and 27b, and the heat dissipating pad portion 28 are made of a Ti film formed on the insulating film 23. Each conductive pattern 25a, 25a, 25b, 25b and the bonding metal layer 29 are formed at the same time, and each external connection electrode 27a, 27a is formed by a laminated film with an Au film formed on the Ti film. , 27b, 27b and the heat radiating pad portion 28 are formed simultaneously. In this embodiment, the thickness of the Ti film on the insulating film 23 is set to 15 to 50 nm, and the thickness of the Au film on the Ti film is set to 500 nm. However, these numerical values are only examples and are particularly limited. Not what you want. Further, the material of each Au film is not limited to pure gold, and may be one added with impurities. In addition, although a Ti film is interposed as an adhesion layer for improving adhesion between each Au film and the insulating film 23, the material of the adhesion layer is not limited to Ti, for example, Cr, Nb, Zr, TiN, TaN or the like may be used. Moreover, although Cu is adopted as the material of the through-hole wiring 24 and the thermal via 26, it is not limited to Cu, and for example, Ni may be adopted.

  Here, in the present embodiment, the die pad portion 25aa of the one conductor pattern 25a constitutes a soaking plate portion in which the entire one surface of the LED chip 1 is bonded and the LED chip 1 and the plurality of thermal vias 26 are thermally coupled. The lead wiring portion 25ab of the one conductor pattern 25 and the other conductor pattern 25 constitute a conductor portion connected to the through-hole wiring 24 around the heat equalizing plate portion. In this embodiment, the heat equalizing plate portion and the conductor portion are formed of the same material, and the heat equalizing plate portion and one conductor portion are continuously formed integrally. May be formed of another material. Further, when the crystal growth substrate of the LED chip 1 is an insulating substrate or a semi-insulating substrate, and the crystal growth substrate is bonded to the soaking plate portion, the material of the soaking plate portion is not necessarily a conductive material. However, the present invention is not limited to this, and any material having a high thermal conductivity (for example, AlN) may be used.

  As shown in FIGS. 6 and 7, the intermediate layer substrate 30 is bonded to the two conductor patterns 27b and 27b of the LED mounting substrate 20 on one surface side (the right side in FIG. 6C) of the silicon substrate 30a. Thus, two conductive patterns 35 and 35 that are electrically connected are formed, and a bonding metal layer 36 that is bonded to the bonding metal layer 29 of the LED mounting substrate 20 is formed. In addition, the intermediate layer substrate 30 is a conductor pattern electrically connected to the conductor patterns 35 and 35 via the through-hole wirings 34 and 34 on the other surface side of the silicon substrate 30a (the left side in FIG. 6C). 37 and 37 are formed, and a bonding metal layer 38 for bonding to the light detection element forming substrate 40 is formed.

  Further, the intermediate layer substrate 30 has two through holes 32 formed therein in the thickness direction of the silicon substrate 30a, and the one surface of the silicon substrate 30a and the other. An insulating film 33 made of a thermal oxide film (silicon oxide film) is formed across the surface and the inner surface of each through hole 32, and each conductor pattern 35, 35, 37, 37 and each bonding metal layer 36, 38 are formed. Each through-hole wiring 34 is electrically insulated from the silicon substrate 30a. Here, each of the conductor patterns 35, 35, 37, 37 and each of the bonding metal layers 36, 38 is a laminated film of a Ti film formed on the insulating film 33 and an Au film formed on the Ti film. The conductor patterns 35 and 35 and the bonding metal layer 36 are formed at the same time, and the conductor patterns 37 and 37 and the bonding metal layer 38 are formed at the same time. In this embodiment, the thickness of the Ti film on the insulating film 33 is set to 15 to 50 nm, and the thickness of the Au film on the Ti film is set to 500 nm. However, these numerical values are only examples and are particularly limited. Not what you want. Here, the material of each Au film is not limited to pure gold, and may be added with impurities. Further, although a Ti film is interposed as an adhesion improving layer for adhesion between each Au film and the insulating film 33, the material of the adhesion layer is not limited to Ti, for example, Cr, Nb, Zr, TiN, TaN or the like may be used. Moreover, although Cu is adopted as the material of the through-hole wiring 34, it is not limited to Cu, and for example, Ni may be adopted.

  As shown in FIGS. 8 and 9, the photodetecting element forming substrate 40 has two conductor patterns 37 and 37 on the intermediate layer substrate 30 on one surface side (right side in FIG. 8C) of the silicon substrate 40a. Two conductor patterns 47 a and 47 b that are bonded and electrically connected are formed, and a bonding metal layer 48 that is bonded to the bonding metal layer 38 of the intermediate layer substrate 30 is formed. Here, the photodetecting element 4 is constituted by a photodiode, and one of the two conductor patterns 47a and 47b formed on the photodetecting element forming substrate 40 (the upper conductor pattern 47a in FIG. 9). Is electrically connected to the p-type region 4a of the photodiode constituting the photodetecting element 4, and the other conductor pattern 47b (lower conductor pattern 47b in FIG. 9) is connected to the n-type region 4b of the photodiode. It is electrically connected to the silicon substrate 40a that constitutes it.

  Further, in the photodetecting element forming substrate 40, an insulating film 43 made of a silicon oxide film is formed on the one surface side of the silicon substrate 40a, and the insulating film 43 also serves as an antireflection film of the photodiode. In the photodetecting element forming substrate 40, the one conductor pattern 47 a is electrically connected to the p-type region 43 a through the contact hole 43 a formed in the insulating film 43, and the other conductor pattern 47 b is connected to the insulating film 43. The n-type region 4b is electrically connected through the formed contact hole 43b. Here, each of the conductor patterns 47a and 47b and the bonding metal layer 48 is composed of a laminated film of a Ti film formed on the insulating film 43 and an Au film formed on the Ti film, and is formed at the same time. It is. In this embodiment, the thickness of the Ti film on the insulating film 43 is set to 15 to 50 nm, and the thickness of the Au film on the Ti film is set to 500 nm. However, these numerical values are only examples and are particularly limited. Not what you want. Here, the material of each Au film is not limited to pure gold, and may be added with impurities. Further, although a Ti film is interposed as an adhesion improving layer for adhesion between each Au film and the insulating film 43, the material of the adhesion layer is not limited to Ti, for example, Cr, Nb, Zr, TiN, TaN or the like may be used.

  In forming the mounting substrate 2 described above, for example, as shown in FIG. 10, the silicon substrate 40a and the intermediate layer on which the photodetecting element 4, the insulating film 43, the respective conductor patterns 47a and 47b, and the bonding metal layer 48 are formed. After performing a first bonding step for bonding the substrate 30 to the substrate 30 by a room temperature bonding method capable of direct bonding at a low temperature, a polishing step for polishing the silicon substrate 40a to a desired thickness is performed, and then inductively coupled plasma ( The light detection element forming substrate 40 is completed by performing the light extraction window forming step of forming the light extraction window 41 on the silicon substrate 40a using an ICP) type dry etching apparatus or the like, and then the LED chip 1 is mounted and bonded. A second bonding step is performed in which the LED mounting substrate 20 to which the wires 14 are connected and the intermediate layer substrate 30 are bonded by a room temperature bonding method or the like. Good. In the normal temperature bonding method, the bonding surfaces are contacted with each other after the bonding surfaces are cleaned and activated by irradiating the bonding surfaces with argon plasma, ion beam or atomic beam in vacuum before bonding. And bond directly at room temperature.

  In the first bonding step, the bonding metal layer 48 of the silicon substrate 40a and the bonding metal layer 38 of the intermediate layer substrate 30 are bonded, and the conductor patterns 47a and 47b of the silicon substrate 40a and the intermediate layer substrate 30 are bonded. The conductor patterns 37 and 37 are joined and electrically connected. Here, since the joint portions of the conductor patterns 47a and 47b and the conductor patterns 37 and 37 are shifted from the region overlapping the through-hole wiring 34, the joint surfaces of the conductor patterns 47a and 47b and the conductor patterns 37 and 37 are mutually connected. The flatness of the substrate can be increased, the junction yield can be increased, and the junction reliability can be increased. In the second bonding step, the bonding metal layer 29 of the LED mounting substrate 20 and the bonding metal layer 36 of the intermediate layer substrate 30 are bonded, and the conductor patterns 25b and 25b of the LED mounting substrate 20 The conductor patterns 35 and 35 of the intermediate layer substrate 30 are joined and electrically connected. Here, since the joint portions of the conductor patterns 25b and 25b and the conductor patterns 35 and 35 are shifted from the region overlapping the through-hole wiring 24 and the region overlapping the through-hole wiring 34, the conductor patterns 25b and 25b and the conductor pattern 35 are arranged. , 35, the flatness of the mutual joint surfaces can be increased, the joint yield can be increased, and the joint reliability can be enhanced.

  Moreover, the above-mentioned translucent member 3 is formed using the translucent board | substrate which consists of translucent materials (for example, silicone, an acrylic resin, glass, etc.). Here, the translucent member 3 is formed in a rectangular plate shape having the same outer peripheral shape as the mounting substrate 2, and all of the light emitted from the LED chip 1 is formed on the light extraction surface opposite to the mounting substrate 2 side. A fine concavo-convex structure that suppresses reflection is formed. Here, the fine concavo-convex structure formed on the light extraction surface of the translucent member 3 is formed such that many fine concave portions have a two-dimensional periodic structure. The fine concavo-convex structure described above may be formed using, for example, a laser processing technique, an etching technique, an imprint lithography technique, or the like. The period of the fine concavo-convex structure may be set as appropriate within a range of about ¼ to 100 times the emission peak wavelength of the LED chip 1.

  In manufacturing the light emitting device of this embodiment, a silicon wafer capable of forming a large number of LED mounting substrates 20, intermediate layer substrates 30, and light detection element formation substrates 40 is used as each of the silicon substrates 20a, 30a, and 40a described above. In addition, a wafer-like one (translucent wafer) capable of forming a large number of translucent members 3 is used as the above-described translucent substrate, and the above-described first bonding step, polishing step, second bonding step, light The mounting substrate after the extraction window forming step, the second bonding step, the sealing portion forming step of filling the housing recess 2a of the mounting substrate 2 with the sealing resin to form the sealing portion 5, and the sealing portion forming step The wafer level package structure is formed by performing each process such as a third joining process for joining 2 and the translucent member 3 at the wafer level, and then divided into the size of the mounting substrate 2 by the dicing process. Yes. Therefore, the LED mounting substrate 20, the intermediate layer substrate 30, the light detection element forming substrate 40, and the translucent member 3 have the same outer size, so that a small package can be realized and manufacturing is facilitated. In addition, since the room temperature bonding method capable of direct bonding at a low temperature is adopted in each of the above-described bonding processes in forming the mounting substrate 2, the junction temperature of the LED chip 1 exceeds the maximum junction temperature in each bonding process. Can be prevented.

  In the light emitting device of the present embodiment described above, the mounting substrate 2 has a cross sectional area of each thermal via 26 in a cross section perpendicular to the thickness direction of the mounting substrate 2 larger than the cross sectional area of each through hole wiring 24, and Since the entire surface of the LED chip 1 is bonded and has the die pad portion 25aa that functions as a heat equalizing plate portion that thermally couples the LED chip 1 and the plurality of thermal vias 26, a heat dissipation path for the heat generated in the LED chip 1 Among these, since there is no section where the cross-sectional area of the heat radiation path is smaller than the chip size of the LED chip 1 between the LED chip 1 and each thermal via 26, the thermal resistance can be reduced and the heat radiation performance is improved. In addition, the number of thermal vias 26 can be reduced without reducing the cross-sectional area of each thermal via 26 in the cross section perpendicular to the thickness direction of the mounting substrate 2. Since it becomes possible to increase, it is possible to improve the heat dissipation more. Therefore, in the light emitting device of the present embodiment, the heat generated in the LED chip 1 can be efficiently released to the outside, and the temperature rise of the junction temperature of the LED chip 1 can be suppressed, so that the input power can be increased and the light output can be increased. High output can be achieved.

  Further, in the light emitting device of the present embodiment, the mounting substrate 2 has a plurality of conductor portions connected to each through-hole wiring 24 formed around the die pad portion 25aa which is a heat equalizing plate portion. Compared with the case where the LED chip 1 and the through-hole wiring 24 overlap in the thickness direction, the number of the thermal vias 26 can be increased, so that heat dissipation can be improved.

  By the way, in the light emitting device having the conventional configuration shown in FIG. 15, the light emitted from the LED chip 1 cannot be detected. However, in the light emitting device of this embodiment, from the peripheral portion of the housing recess 2 a in the mounting substrate 2. Since the light detection element 4 for detecting the light emitted from the LED chip 1 is provided on the projecting portion 2c protruding inward, the light emitted from the LED chip 1 can be detected. Therefore, for example, a light emitting device that employs a red LED chip as the LED chip 1, a light emitting device that employs a green LED chip as the LED chip 1, and a light emitting device that employs a blue LED chip as the LED chip 1 are the same circuit board. Arranged close to each other, the drive circuit unit for driving the LED chip 1 of each light emitting device on the circuit board and the light intensity detected by each light detection element 4 are maintained at the respective target values. By providing a control circuit unit that feedback-controls the current flowing from the drive circuit unit to the LED chip 1 of each emission color, the light output of the LED chip 1 of each emission color is based on the output of each of the light detection elements 4. Can be controlled separately, and the mixed color light (in this case, white light) can be controlled regardless of the temporal change in the light output of the LED chip 1 for each emission color. It is possible to improve the accuracy of color or color temperature. In short, in the light emitting device of this embodiment, it is possible to stably obtain desired mixed color light.

  In the present embodiment, one LED chip 1 is mounted on the inner bottom surface of the housing recess 2a of the mounting substrate 2. However, the number of LED chips 1 is not particularly limited, and a plurality of light emission colors are the same. The LED chip 1 may be mounted on the inner bottom surface of the storage recess 2a.

(Embodiment 2)
Hereinafter, the light-emitting device of this embodiment will be described with reference to FIGS.

  The basic configuration of the light emitting device of the present embodiment is substantially the same as that of the first embodiment, and a plurality (four in the illustrated example) of LED chips 1 having different emission colors are provided on the inner bottom surface of the housing recess 2a of the mounting substrate 2. A plurality of light detection elements 4 (four in the illustrated example) that are mounted and detect light emitted from the respective LED chips 1 of the respective emission colors are provided on the light detection element forming substrate 40. Is different. Here, in this embodiment, as the four LED chips 1, the LED chip 1a whose emission color is red, the LED chip 1b whose emission color is green, the LED chip 1c whose emission color is blue, and the emission color which is yellow are shown. The LED chip 1d is employed, and white light can be obtained as mixed color light of red light, green light, blue light, and yellow light. However, the emission color of each LED chip 1 is not particularly limited, and may be appropriately selected according to the desired mixed color light. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted.

  In the light emitting device of this embodiment, in order to selectively detect only the light emitted from the corresponding LED chips 1a to 1d in each light detection element 4, the light emitted from each of the LED chips 1a to 1d. A cross-shaped light shielding wall 39 that restricts the radiation range is formed integrally with the intermediate layer substrate 30 continuously. In short, in the light emitting device of this embodiment, the opening window 31 of the intermediate layer substrate 30 is divided into four small spaces 31 a by the light shielding wall 39. Here, in this embodiment, the light shielding wall 39 in the intermediate layer substrate 30 is formed simultaneously with the opening window 31 by anisotropic etching using an alkaline solution, and each side surface of the light shielding wall 39 is within the opening window 31. Since it is a (111) plane like the side surface, each side surface of the light shielding wall 39 functions as a mirror that reflects light emitted from the LED chips 1a to 1d forward.

  Thus, in the light emitting device according to the present embodiment, the light emitted from the LED chips 1a to 1d of the respective emission colors can be detected with high accuracy by the respective light detecting elements 4, and each of the light detecting elements 4 can be detected. On the basis of the output, the light output of each of the LED chips 1a to 1d of the respective emission colors can be controlled separately, and the desired mixed color light can be stably obtained. That is, the light intensity detected by the drive circuit unit that drives each LED chip 1a to 1d and each photodetecting element 4 is maintained at the target value on the circuit board on which the light emitting device of this embodiment is mounted. Is provided with a control circuit unit that feedback-controls the current flowing from the drive circuit unit to each of the LED chips 1a to 1d, so that each of the LED chips 1a to 1d of each emission color is based on the output of each of the light detection elements 4. The light output can be controlled separately, and the light color of the mixed color light (here, white light) regardless of the temporal change in the light output of the LED chips 1a, 1b, 1c, 1d for each emission color, The accuracy of the color temperature can be improved.

  In the first and second embodiments, the mounting substrate 2 is formed using three semiconductor substrates. However, the number of semiconductor substrates on which the mounting substrate 2 is based is not particularly limited. For example, Similarly to the conventional example shown in FIG. 15, it may be formed using one semiconductor substrate, or may be formed using two semiconductor substrates.

1 is a schematic cross-sectional view of a light emitting device according to Embodiment 1. FIG. It is a general | schematic disassembled perspective view of a light-emitting device same as the above. The mounting board | substrate is shown, (a) is a schematic plan view, (b) is A-A 'schematic sectional drawing of (a), (c) is B-B' schematic sectional drawing of (a). The board | substrate for LED mounting same as the above is shown, (a) is a schematic plan view, (b) is AA 'schematic sectional drawing of (a), (c) is BB' schematic sectional drawing of (a). . It is a schematic bottom view of the board | substrate for LED mounting in the same as the above. The intermediate | middle layer board | substrate in the same is shown, (a) is a schematic plan view, (b) is A-A 'schematic sectional drawing of (a), (c) is B-B' schematic sectional drawing of (a). It is a schematic bottom view of the intermediate | middle layer board | substrate in the same as the above. The optical detection element formation board in the same as above is shown, (a) is a schematic plan view, (b) is an AA 'schematic sectional view of (a), (c) is a BB' schematic sectional view of (a). is there. It is a schematic bottom view of the optical detection element formation board | substrate in the same as the above. It is explanatory drawing of the formation method of the mounting board | substrate in the same as the above. 6 is a schematic cross-sectional view of a light emitting device according to Embodiment 2. FIG. It is a principal part schematic plan view of a light-emitting device same as the above. It is a general | schematic disassembled perspective view of a light-emitting device same as the above. It is a schematic bottom view of the light detection element formation board | substrate in the light-emitting device same as the above. A prior art example is shown, (a) is a schematic plan view, and (b) is a schematic cross-sectional view along A-A 'of (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 LED chip 2 Mounting substrate 20a, 30a, 40a Silicon substrate (semiconductor substrate)
22a Through-hole 22b Through-hole 23 Insulating film 24 Through-hole wiring 25a Conductor pattern 25aa Die pad part (heat equalizing plate part)
25ab Lead-out wiring part (conductor part)
26 Thermal Via 27a External Connection Electrode 28 Heat Dissipation Pad

Claims (2)

An LED chip and a mounting substrate formed using a semiconductor substrate and mounted with the LED chip, a plurality of through-hole wirings serving as part of a power feeding path to the LED chip, and a heat dissipation path for heat generated in the LED chip; A plurality of thermal vias are provided in the thickness direction of the mounting board, wherein the mounting board has a cross-sectional area of each thermal via in a cross-section orthogonal to the thickness direction than the cross-sectional area of each through-hole wiring It is large and has a heat equalizing plate portion that is bonded to the entire surface of the LED chip and thermally couples the LED chip and the plurality of thermal vias, and the mounting substrate includes an LED mounting portion on which the LED chip is mounted, The LED mounting portion has a wall portion provided in a peripheral portion of the region where the LED chip is mounted and a protruding portion protruding from the wall portion, and detects light emitted from the LED chip on the protruding portion. Light emitting device and a light detecting element is provided.   The light emitting device according to claim 1, wherein the mounting substrate is formed with a plurality of conductor portions connected to the through-hole wirings around the heat equalizing plate portion.

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