JP2024037339A - Light emitting device and light emitting device module - Google Patents

Abstract

[Problem] To provide a light emitting device and a light emitting device module capable of efficiently dissipating heat from a semiconductor light emitting element included in the light emitting device to the outside. [Solution] The light emitting device of the present invention comprises a substrate having metal wiring on its upper surface and made of insulating ceramic, a light emitting element joined to the upper surface of the substrate via the metal wiring, and a heat transfer section including a plurality of metal bodies that are electrically insulated from the metal wiring and each of which is joined to the lower surface of the substrate and protrudes downward from the lower surface. [Selected Figure] Figure 2

Description

The present invention relates to a light emitting device and a light emitting device module including a semiconductor light emitting element.

Conventionally, light-emitting device modules have been known that include a light-emitting device including a semiconductor light-emitting element and a radiator such as a heat sink attached to one surface of the light-emitting device, particularly the surface opposite to the light-emitting surface of the light-emitting device. There is.

For example, Patent Document 1 discloses a metal base with a screw provided on the lower surface, a light emitting diode chip attached to the upper surface of the metal base, and a light emitting diode chip and an electric light emitting diode chip installed on the upper surface of the metal base. A light emitting diode is disclosed having a circuit board connected to the metal base, and a heat sink mechanically coupled directly to the underside of the metal base via screws of the metal base.

Special Publication No. 2005-513815

In the light emitting diode described in Patent Document 1, when the metal base and the heat sink are directly mechanically connected, the contact thermal resistance at the contact surface between the metal base and the heat sink is large, so the thermal resistance between the metal base and the heat sink is large. turn into.

In addition, in the light emitting diode described in Patent Document 1, when using a general thermal conductive adhesive in which an inorganic filler is dispersed in a resin base material between the metal base and the heat sink, the resin is used as the base material. Since the thermal conductivity of the thermally conductive adhesive is low, the thermal resistance between the metal base and the heat sink increases.

Therefore, in the light emitting diode described in Patent Document 1, heat can be efficiently conducted from the light emitting diode chip to the heat sink due to the contact thermal resistance at the contact surface between the metal base and the heat sink or the thermal resistance of the thermally conductive adhesive. The problem is that it cannot be done.

The present invention has been made in view of the above points, and aims to provide a light emitting device and a light emitting device module that can efficiently dissipate heat from a semiconductor light emitting element included in the light emitting device to the outside. The purpose is

A light emitting device according to the present invention includes a substrate made of insulating ceramic and having metal wiring on the upper surface, a light emitting element bonded to the upper surface of the substrate via the metal wiring, and an electrical connection with the metal wiring. The heat transfer section includes a plurality of insulated metal bodies, each of which is bonded to the lower surface of the substrate and protrudes downward from the lower surface of the substrate.

Further, the light emitting device module according to the present invention includes a substrate having metal wiring on the upper surface and made of insulating ceramic, a light emitting element bonded to the upper surface of the substrate via the metal wiring, and the metal wiring. a light emitting device including a plurality of electrically insulated metal bodies, each of which is bonded to the lower surface of the substrate and protrudes downward from the lower surface of the substrate; A light emitting device module comprising: an insulating circuit board having a pair of circuit wires electrically connected to the metal wires; and a radiator disposed on the lower surface of the circuit board, the light emitting device module comprising: A plurality of circuit board through holes penetrating from an upper surface to a lower surface are formed at positions corresponding to the plurality of metal bodies of the light emitting device, and each of the plurality of metal bodies of the light emitting device is formed at a position corresponding to the plurality of metal bodies. It passes through the plurality of circuit board through-holes of the circuit board and protrudes from the lower surface of the circuit board, and is bonded to the heat radiator at the protruding portion by a heat transfer part bonding material made of metal. .

1 is a top view of a light emitting device according to Example 1 of the present invention. 1 is a cross-sectional view of a light emitting device according to Example 1 of the present invention. 1 is a cross-sectional view of a light emitting device according to Example 1 of the present invention. 1 is a sectional view of a light emitting device module according to Example 1 of the present invention. FIG. 2 is a cross-sectional view of a light emitting device module according to Example 2 of the present invention. FIG. 3 is a cross-sectional view of a light emitting device according to modification example 1 of the present invention. FIG. 7 is a cross-sectional view of a light emitting device according to Modification 2 of the present invention. FIG. 7 is a cross-sectional view of a light emitting device according to modification example 3 of the present invention. FIG. 7 is a cross-sectional view of a light emitting device according to modification example 4 of the present invention. FIG. 7 is a cross-sectional view of a light emitting device according to modification 5 of the present invention.

Examples of the present invention will be described in detail below. In the following description and accompanying drawings, substantially the same or equivalent parts are designated by the same reference numerals.

The configuration of a light emitting device 10 according to Example 1 will be described with reference to FIGS. 1 to 3. FIG. 1 is a top view of a light emitting device 10 according to Example 1. 2 is a cross-sectional view of the light emitting device 10 shown in FIG. 1 taken along line 2-2. 3 is a cross-sectional view of the light emitting device 10 shown in FIG. 1 taken along line 3-3. Note that in FIG. 1, illustration of the light reflector 50 (see FIGS. 2 and 3) is omitted in order to clarify the structure and positional relationship of each element on the upper surface of the substrate 11.

(Light emitting device 10)
The light emitting device 10 includes a flat substrate 11, a pair of electrodes extending from the top surface to the bottom surface of the substrate 11, ie, a first wiring electrode 13 and a second wiring electrode 15, and an intermediate electrode formed on the top surface of the substrate 11. A plurality of light emitting elements 20 and a plurality of light emitting elements are bonded to each of the upper surfaces of the wiring 17, the adjacent first wiring electrode 13, the second wiring electrode 15, and the intermediate wiring 17 via the element bonding layer 30. 20, and a light reflector 50 formed on the upper surface of the substrate 11 so as to expose the upper surface of the wavelength converter 40.

The light emitting device 10 also includes a heat dissipation structure 60 having a metal layer 61 bonded to the lower surface of the substrate 11 and a heat transfer pin 63 bonded to the lower surface of the metal layer 61, which is the surface opposite to the substrate 11.

(Substrate 11)
The substrate 11 is a flat substrate having a rectangular planar shape and made of aluminum nitride (AlN, thermal conductivity: 170 W/m·K) having high thermal conductivity. The substrate 11 may be, for example, another insulating ceramic substrate having high thermal conductivity such as alumina (Al ₂ O ₃ ).

The first wiring electrode 13 and the second wiring electrode 15 are a pair of metal electrodes that are formed on the substrate 11 and are spaced apart and electrically insulated from each other.

The first wiring electrode 13 includes a first internal wiring 13I formed on one end of the upper surface of the substrate 11 in the longitudinal direction, and a first internal wiring 13I formed on one end of the lower surface of the substrate 11 in the longitudinal direction. It has an electrode 13O. Further, the first wiring electrode 13 has a first through electrode 13V that penetrates the substrate 11 and electrically connects the first internal wiring 13I and the first mounting electrode 13O.

The second wiring electrode 15 has the same configuration as the first wiring electrode 13, and includes a second internal wiring 15I formed on the other end side in the longitudinal direction of the upper surface of the substrate 11, and a second internal wiring 15I formed on the other end side in the longitudinal direction of the upper surface of the substrate It has a second mounting electrode 15O formed on the other end side in the longitudinal direction of the lower surface of 11. Further, the second wiring electrode 15 has a second through electrode 15V that penetrates the substrate 11 and electrically connects the second internal wiring 15I and the second mounting electrode 15O.

The intermediate wiring 17 is a metal wiring arranged in the longitudinal direction between the first internal wiring 13I and the second internal wiring 15I on the upper surface of the substrate 11 and spaced apart from each other.

The first wiring electrode 13, the second wiring electrode 15, and the intermediate wiring 17 each have a copper (Cu) layer formed on the surface of the substrate 11, and a nickel (Ni) layer and a gold layer on the surface of the Cu layer. (Au) layers are laminated in this order.

The first wiring electrode 13, the second wiring electrode 15, and the intermediate wiring 17 are formed by forming a metal thin film layer by, for example, vacuum deposition such as vapor deposition (film formation by high-energy metal particle irradiation: PVD (Physical Vapor Deposition)). After that, it is formed by plating or the like. By forming in this manner, the substrate 11 made of ceramic, and the first wiring electrode 13, second wiring electrode 15, and intermediate wiring 17 made of metal are closely joined. Other forming methods include a CVD (Chemical Vapor Deposition) method and a plating method. The metal layer formed in this way has airtightness at the film-forming interface. That is, both are strongly bonded chemically and/or physically.

Thereby, the contact thermal resistance between the substrate 11 and the first wiring electrode 13, the second wiring electrode 15, and the intermediate wiring 17 can be reduced.

In addition, the first wiring electrode 13, second wiring electrode 15, and intermediate wiring 17 made of metal have high thermal conductivity (Cu thermal conductivity: approximately 380 W/m·K, Ni thermal conductivity: approximately 90 W/m.K. /m・K, Au thermal conductivity: approximately 300 W/m・K). Therefore, heat can be efficiently conducted from the first wiring electrode 13, the second wiring electrode 15, and the intermediate wiring 17 to the substrate 11.

(Light emitting element 20)
The light emitting element 20 is a semiconductor light emitting element such as a light emitting diode (LED) arranged on the upper surface of the substrate 11. In Example 1, an LED element that emits blue light was used as the light emitting element 20.

The light-emitting element 20 includes a plate-shaped growth substrate 21 having light-transmitting properties, a semiconductor structure layer (not shown) including a light-emitting layer formed on the lower surface of the growth substrate 21, and a growth substrate 21 for the semiconductor structure layer. It has a structure including element electrodes 23 and 25, which are a pair of electrodes formed on the opposite surface to the contacting surface, that is, the lower surface.

The light emitting element 20 is mounted such that the lower surface of the growth substrate 21 on which the element electrodes 23 and 25 are formed faces the upper surface of the substrate 11. Further, in the light emitting element 20, the lower surfaces of the element electrodes 23 and 25 are respectively bonded to the upper surfaces of the first internal wiring 13I, the second internal wiring 15I, and the intermediate wiring 17 via the element bonding layer 30. . That is, the light emitting element 20 is a flip-chip type light emitting element in which the active surface, on which the semiconductor structure layer is formed, is inverted and bonded to the substrate 11.

The light emitting element 20 is disposed so as to straddle adjacent wiring lines on the upper surface of the substrate 11, and the element electrodes 23 and 25 of the light emitting element 20 are placed on the upper surface of each of the adjacent wiring lines with an element bonding layer 30 interposed therebetween. are joined together. That is, the light emitting element 20 is electrically connected in series between the first wiring electrode 13 and the second wiring electrode 15 via the intermediate wiring 17.

The element bonding layer 30 is, for example, a metal alloy such as gold-tin (AuSn) formed by eutectic bonding. That is, each wiring and the light emitting element 20 are closely bonded by a metal alloy that has been melted by heating during bonding. In other words, each wiring and the element electrodes 23 and 25 of the light emitting element 20 are welded to each other by the element bonding layer 30.

Thereby, the contact thermal resistance between the light emitting element 20 and the first wiring electrode 13, the second wiring electrode 15, and the intermediate wiring 17 can be reduced.

Further, the light emitting element 20, the first wiring electrode 13, the second wiring electrode 15, and the intermediate wiring 17 are bonded with AuSn, which is a metal alloy with high thermal conductivity (thermal conductivity: approximately 60 W/m·K). Therefore, heat generated from the light emitting element 20 is efficiently conducted to the substrate 11 via the element bonding layer 30, the first wiring electrode 13, the second wiring electrode 15, and the intermediate wiring 17.

(Wavelength converter 40)
The wavelength converter 40 has a plate-like shape and is arranged on the upper surface of each light emitting element 20. The wavelength converter 40 is bonded onto the top surface of each of the light emitting elements 20 using a translucent resin such as silicone resin, epoxy resin, or acrylic resin.

The wavelength converter 40 wavelength-converts a part of the emitted light of the light-emitting element 20 that enters from the lower surface, which is the surface facing the light-emitting element 20, and outputs the light from the upper surface.

In Example ₁ , as the wavelength _converter 40, phosphor particles of yttrium aluminum garnet (YAG:Ce, _Y3Al5O12 :Ce) doped with cerium (Ce) and ceramic particles as a binder are mixed. A sintered body was used. Further, in Example 1, the content of the phosphor particles is adjusted so that the wavelength converter 40 converts a part of the blue light emitted from the light emitting element 20 into yellow light and emits white light. There is.

(Light reflector 50)
The light reflector 50 is arranged on the upper surface of the substrate 11 so as to cover the exposed surfaces of the first internal wiring 13I, the second internal wiring 15I, the intermediate wiring 17 and the light emitting element 20, and the side surface of the wavelength converter 40. is formed.

The light reflector 50 reflects the light emitted from the side surface of the light emitting element 20 and the light emitted from the side surface of the wavelength converter 40 inwardly, and guides the light to the upper surface of the wavelength converter 40 .

In Example 1, a thermosetting silicone resin mixed with titanium oxide (TiO ₂ ) particles, which are light-scattering particles, was used.

(Heat dissipation structure 60)
The heat dissipation structure 60 as a heat transfer part is composed of a metal layer 61 formed on the lower surface of the substrate 11 and a heat transfer pin 63 arranged on the lower surface of the metal layer 61, and transfers heat generated from the light emitting element 20 to the substrate 11. Heat is transferred or radiated to the outside of the light emitting device 10 through the light emitting device 10 .

The metal layer 61 is a layer made of metal that is formed on the lower surface of the substrate 11 in a region separated from the first mounting electrode 13O and the second mounting electrode 15O. That is, the metal layer 61 is insulated from the first wiring electrode 13 and the second wiring electrode 15.

The metal layer 61 has, for example, a Cu layer formed on the surface of the substrate 11, and Ni and Au are laminated in this order on the surface of the Cu layer.

The metal layer 61 is formed, for example, by electroplating or the like after a metal thin film layer is formed by vacuum film formation such as vapor deposition. By forming in this way, the substrate 11 made of ceramic and the metal layer 61 made of metal are closely bonded together, similarly to the first wiring electrode 13, the second wiring electrode 15, and the intermediate wiring 17. There is.

Thereby, the contact thermal resistance between the substrate 11 and the metal layer 61 can be reduced.

In addition, the metal layer 61 made of metal has high thermal conductivity (Cu thermal conductivity: approximately 380 W/m・K, Ni thermal conductivity: approximately 90 W/m・K, Au thermal conductivity: approximately 300 W/m・K). Therefore, heat can be efficiently conducted from the substrate 11 to the metal layer 61.

Furthermore, the metal layer 61 whose main material is Cu has higher thermal conductivity than the substrate 11. Therefore, the metal layer 61 also functions as a heat collecting section that collects the heat conducted from the light emitting element 20 to the substrate 11.

The heat transfer pin 63 as a metal body is, for example, a metal made of Cu, and a Ni layer and an Au layer are laminated in this order on the surface. In the first embodiment, a total of 15 heat transfer pins 63 arranged in 3 rows and 5 columns are bonded to the lower surface of the metal layer 61 in a matrix.

The heat transfer pin 63 includes, for example, a disk-shaped head portion formed at one end and a pin-shaped portion having a cylindrical pin shape. The heat transfer pin 63 is joined to the metal layer 61 by having its head portion brazed to the lower surface of the metal layer 61 with a brazing material 65 such as a silver brazing material. That is, the heat transfer pin 63 and the metal layer 61 are closely bonded using a bonding material containing metal that has been molten by heating during bonding. In other words, the heat transfer pin 63 and the metal layer 61 are joined to each other by the brazing material 65.

Thereby, the contact thermal resistance between the metal layer 61 and the heat transfer pin 63 can be reduced.

Furthermore, since the metal layer 61 and the heat transfer pin 63 are joined by a silver brazing material containing a metal with high thermal conductivity (thermal conductivity: approximately 100 W/m·K), the heat from the substrate 11 is The heat is efficiently conducted to the heat transfer pin 63 via the metal layer 61.

In addition, in Example 1, the case where the heat transfer pin 63 consists of a disk-shaped head part and a cylindrical pin-shaped part was demonstrated, but the shape of the heat transfer pin 63 is not limited to this. For example, the heat transfer pin 63 may consist of a rectangular plate-shaped head portion and a square columnar pin-shaped portion, or may consist of a polygonal plate-shaped head portion and a polygonal columnar pin-shaped portion. good.

As described above, the light emitting device 10 of Example 1 does not use a bonding material whose base material is a resin material between the light emitting element 20 and the heat transfer pin 63. In addition, it does not have a structure with high contact thermal resistance in which metals and metals or metals and ceramics are mechanically brought into close contact with each other using screws or the like. That is, the members from the light emitting element 20 to the heat transfer pin 63 of the present invention have a structure in which both members are firmly bonded chemically and/or physically.

Note that in order to obtain a high heat dissipation effect, the cross section is determined by dividing the sum of the cross-sectional areas (ΣSp) of the cylindrical pin-shaped portions of the heat transfer pins 63 by the sum of the areas of the device electrodes 23 and 25 of the light-emitting element 20 (ΣSe). The ratio (Rpe=ΣSp/ΣSe) is preferably about 0.4 to 3 times. If the cross-sectional ratio (Rpe) is 0.4 or more, heat dissipation can be improved compared to a bonding member whose base material is a resin material. Further, by setting the cross-sectional ratio (Rpe) to 3 or less, the area of the substrate 11 can be kept small. This is not the case if the area of the substrate 11 can be expanded.

For example, a bonding material made of a resin material containing an inorganic filler has very low thermal conductivity (less than 10 W/m·K) and is not sufficient to efficiently conduct heat generated from the light emitting element 20. Further, when the base material is a thermosetting resin, gaps may be formed at the bonding surface due to the generation of voids or shrinkage due to curing due to heating, and there is a risk that the contact thermal resistance will increase.

In the light emitting device 10 of Example 1, ceramic and metal with high thermal conductivity are used for the substrate 11, the first wiring electrode 13, the second wiring electrode 15, the intermediate wiring 17, the metal layer 61, and the heat transfer pin 63. ing. Furthermore, the bonding material used to bond the respective constituent members is also a bonding material with high thermal conductivity, and the bonded portion is formed to have extremely low contact thermal resistance.

Therefore, the heat generated from the light emitting element 20 can be efficiently conducted to the heat transfer pin 63 and dissipated to the outside.

(Light emitting device module 100)
FIG. 4 is a cross-sectional view of a light emitting device module 100 equipped with the light emitting device 10 according to the first embodiment. FIG. 4 is a cross section of the light emitting device 10 shown in FIG. 1, taken along line 2-2.

The light emitting device module 100 includes a light emitting device 10, a circuit board 70, and a heat sink 80. In the light emitting device module 100, the light emitting device 10 is mounted on the upper surface of the circuit board 70, and the heat sink 80 is attached to the lower surface of the circuit board 70.

(Circuit board 70)
The circuit board 70 is an insulating board made of glass fiber-reinforced epoxy resin or the like, and has an electrical connection with the first mounting electrode 13O and the second mounting electrode 15O of the light-emitting device 10 on the upper surface on which the light-emitting device 10 is mounted. A pair of circuit wirings 73 and 75 are provided.

Further, the circuit board 70 has a plurality of circuits disposed in a region between the circuit wirings 73 and 75 at a position facing the heat transfer pin 63 of the light emitting device 10 and penetrating from the top surface to the bottom surface of the circuit board 70. A substrate through hole 70H is formed. Each of the heat transfer pins 63 of the light emitting device 10 mounted on the circuit board 70 is inserted so as to pass through the circuit board through hole 70H and protrude from the lower surface of the circuit board 70. In the circuit board 70 and the light emitting device 10, the first mounting electrode 13O and the second mounting electrode 15O and a pair of circuit wirings 73 and 75 of the circuit board 70 are bonded via a device bonding layer 78 such as solder. They are joined together by this.

Further, the heat transfer pin 63 of the light emitting device 10 is separated from and electrically insulated from the pair of circuit wirings 73 and 75 of the circuit board 70.

(Radiator 80)
The heat sink 80 is a heat sink placed on the bottom surface of the circuit board 70. The heat radiator 80 has heat radiation fins 81 formed on its lower surface. The heat radiator 80 is arranged such that its upper surface, which is the opposite surface to the lower surface on which the radiation fins 81 are formed, faces the lower surface of the circuit board 70.

The heat radiator 80 is made of a metal with high thermal conductivity, such as aluminum (Al, thermal conductivity: about 220 W/m·K), for example.

Further, a plurality of recesses 80F are formed on the lower surface of the heat radiator 80 at positions between adjacent heat radiating fins 81 and facing the tips of the heat transfer pins 63. Further, a radiator through hole 80H that penetrates to the upper surface of the radiator 80 is formed at the bottom of each of the recesses 80F. The tip of the heat transfer pin 63 of the light emitting device 10 passes through the heat radiator through hole 80H from the upper surface of the radiator 80 and reaches the inside of the recess 80F.

The heat radiator 80 is fixed by a fixture PP such as an insulating push pin that passes through the circuit board 70 and the heat radiator 80, for example.

The concave portion 80F of the radiator 80 is filled with a radiator bonding material 85 as a heat transfer part bonding material containing metal such as solder, and the heat radiator bonding material 85 connects the heat transfer pin 63 and the radiator 80. It is joined. That is, the heat transfer pin 63 and the heat radiator 80 are bonded together using a bonding material containing metal that has undergone a molten state due to heating during bonding. In other words, the heat transfer pin 63 and the heat sink 80 are welded to each other by the heat sink bonding material 85.

Thereby, the contact thermal resistance between the heat transfer pin 63 and the heat radiator 80 can be reduced.

Furthermore, since the heat transfer pin 63 and the heat sink 80 are bonded with the heat sink bonding material 85 (thermal conductivity: approximately 60 W/m·K), which is a metal alloy solder having high thermal conductivity, the heat transfer pin 63 and the heat sink 80 are Heat from the thermal pins 63 is efficiently conducted to the heat sink 80.

With the above configuration, in the light emitting device module 100 of Example 1, a heat radiation path is formed between the light emitting element 20 of the light emitting device 10 and the radiator 80 without using a member with low thermal conductivity including a resin material or the like. can do. Furthermore, since each joint is closely joined by a joining material containing metal that has undergone a molten state during joining, it is possible to reduce the contact thermal resistance at the joint interface of the joint to a virtually negligible level. can.

Therefore, according to the first embodiment, the heat generated from the light emitting element 20 of the light emitting device 10 can be efficiently conducted to the heat radiator 80 and radiated from the heat radiator 80 to the outside of the light emitting device module 100.

Note that the heat sink 80 is not limited to a heat sink. For example, when the light emitting device module 100 is used as a lamp, the radiator 80 may be a bracket, a reflector, a casing, or the like. In other words, the radiator 80 may be a radiator itself, or may be a member such as a fixture or a casing that also functions as a radiator. Furthermore, the heat radiator 80 may be a member that serves as a radiation path for heat from the light emitting device 10.

(Method for manufacturing light emitting device module 100)
The light emitting device module 100 can be manufactured by the following method.

First, solder paste, which is a raw material paste for the device bonding layer 78, is applied onto the upper surface of a pair of circuit wirings 73 and 75 formed on the upper surface of the circuit board 70 (step 1).

Next, the first mounting electrode 13O and the second mounting electrode 15O are brought into contact with the raw material paste of the device bonding layer 78 while inserting the heat transfer pin 63 of the light emitting device 10 (Step 2).

The circuit board 70 in this state is placed in a reflow oven, the raw material paste of the device bonding layer 78 is melted, and the circuit board 70 and the light emitting device 10 are bonded (step 3).

Next, the circuit board 70 is turned upside down, and the heat transfer pin 63 protruding from the circuit board 70 is inserted into the heat radiator through hole 80H of the radiator 80, and the radiator 80 is fixed with the fixture PP (step 4). .

Next, the recess 80F of the radiator 80 is filled with solder paste, which is a raw material for the radiator bonding material 85 (step 5).

Thereafter, the solder paste, which is the raw material for the heat sink joining material 85, is melted by a heating means such as a heat gun, and the heat transfer pin 63 and the heat sink 80 are joined together (Step 6).

By performing the above steps, the light emitting device module 100 can be manufactured.

In the first embodiment, a case has been described in which the recess 80F and the radiator through hole 80H are formed on the lower surface of the radiator 80. However, the structure of the heat sink 80 is not limited to this.

(Light emitting device module 100A)
FIG. 5 is a diagram showing a cross section of a light emitting device module 100A according to the second embodiment. FIG. 5 is a cross section of the light emitting device 10 shown in FIG. 1, taken along line 2-2.

The second embodiment differs from the first embodiment in that a recess 90F of the heat radiator 90 is formed on the upper surface of the heat radiator 90. The configurations of the light emitting device 10 and the circuit board 70 are the same as in the first embodiment.

(Radiator 90)
A recess 90F is formed on the upper surface of the heat radiator 90 at a position corresponding to the heat transfer pin 63 of the light emitting device 10.

The heat transfer pin 63 of the light emitting device 10 is inserted into the circuit board through hole 70H from the upper surface of the circuit board 70, and reaches the inside of the recess 90F of the heat radiator 90.

The recess 90F of the radiator 90 is filled with a radiator bonding material 85 containing metal such as solder, and the heat transfer pin 63 and the radiator 90 are bonded via the radiator bonding material 85.

Also in the light emitting device module 100A of Example 2, similarly to the light emitting device module 100, the heat transfer pin 63 and the radiator 90 are closely bonded using a bonding material containing a metal that has undergone a molten state due to heating during bonding. There is.

Further, the light emitting device module 100A can form a heat radiation path between the light emitting element 20 of the light emitting device 10 and the heat radiator 90 without using a member with low thermal conductivity including a resin material or the like.

Therefore, in the second embodiment as well, the heat generated from the light emitting element 20 of the light emitting device 10 can be efficiently conducted to the heat radiator 90 and radiated from the heat radiator 90 to the outside of the light emitting device module 100A.

Note that in the configuration of the light emitting device module 100A of Example 2, as shown in FIG. 5, it is preferable to provide a spacer SP that separates the lower surface of the circuit board 70 and the upper surface of the radiator 90 by a predetermined distance. Thereby, it is possible to suppress creeping up or leakage of the solder paste, which is the raw material of the heat sink joining material 85 filled in the recess 90F of the heat sink 90.

(Method for manufacturing light emitting device module 100A)
In the light emitting device module 100A of the second embodiment, the heat radiator 90 has the above-described structure, so that the number of heat bonding steps of the solder paste can be reduced.

Specifically, first, solder paste, which is a raw material paste for the device bonding layer 78, is applied onto the upper surfaces of a pair of circuit wirings 73 and 75 formed on the upper surface of the circuit board 70 (step 1).

Next, the recess 90F of the radiator 90 is filled with solder paste, which is a raw material for the radiator bonding material 85 (step 2).

Next, the heat radiator 90 is fixed with the fixture PP so that the circuit board through hole 70H of the circuit board 70 and the recess 90F of the heat radiator 90 are fixed at corresponding positions (step 3).

Next, while inserting the heat transfer pin 63 of the light emitting device 10 into the circuit board through hole 70H, the first mounting electrode 13O and the second mounting electrode 15O are brought into contact with the raw material paste of the device bonding layer 78, and the heat transfer The pins 63 are brought into contact with the solder paste that is the raw material for the heatsink bonding material 85 (step 4).

The circuit board 70 in this state is placed in a reflow oven to melt the raw material paste of the device bonding layer 78 and the solder paste that is the raw material of the radiator bonding material 85, thereby bonding the light emitting device 10, the circuit board 70, and the radiator 90. (Step 5).

By performing the above steps, the light emitting device module 100A can be manufactured more easily.

[Modification 1]
In the heat dissipation structure 60 of Example 1, a case has been described in which the heat transfer pins 63 are bonded to the surface of the metal layer 61 formed on the lower surface of the substrate 11 by brazing using the brazing material 65. However, the method of joining the heat transfer pins 63 is not limited to this.

FIG. 6 is a cross-sectional view of a light emitting device 10A according to modification 1. FIG. 6 is a cross section of the light emitting device 10 shown in FIG. 1, taken along line 2-2.

The light emitting device 10A is different from the light emitting device 10 of the first embodiment in that it has a heat dissipation structure 60A in which a metal layer 61 and a heat transfer pin 63 are integrally formed on the lower surface of the substrate 11.

In the heat dissipation structure 60A, a heat transfer pin 63 is bonded to the surface of a metal layer 61 formed on the lower surface of the substrate 11 by diffusion bonding.

Specifically, the heat dissipation structure 60A presses the head portion of the heat transfer pin 63 against the metal layer 61 formed on the lower surface of the substrate 11 and heats and pressurizes the metal layer 61 to conduct heat transfer with the atoms of the metal layer 61 at the contact interface. Bonding is performed by mutually diffusing the atoms of the thermal pin 63.

By performing diffusion bonding, the interface between the metal layer 61 and the heat transfer pin 63 almost disappears, and a heat dissipation structure 60A in which the metal layer 61 and the heat transfer pin 63 are integrated can be formed.

Thereby, the contact thermal resistance at the interface between the metal layer 61 and the heat transfer pin 63 can be made almost zero. Therefore, for example, when the light emitting device 10A is incorporated into the light emitting device module 100, the heat generated from the light emitting element 20 can be more efficiently conducted to the heat radiator 80, and the heat generated from the light emitting device 20 can be conducted to the outside of the light emitting device module 100 from the heat radiator 80. It becomes possible to dissipate.

[Modification 2]
FIG. 7 is a cross-sectional view of a light emitting device 10B according to modification 2. FIG. 7 is a cross section of the light emitting device 10 shown in FIG. 1, taken along line 2-2.

The light emitting device 10B differs from the light emitting device 10 of Example 1 in that the heat dissipation structure 60B does not have the metal layer 61.

In the heat dissipation structure 60B, a heat transfer pin 63 is directly bonded to the lower surface of the substrate 11 via an active brazing material 65A.

By directly brazing the heat transfer pin 63 to the lower surface of the substrate 11 using the active brazing material 65A, the number of joints between members between the light emitting element 20 and the heat transfer pin 63 can be reduced.

Thereby, for example, when the light emitting device 10B is assembled into the light emitting device module 100, it becomes possible to further reduce the composite contact thermal resistance at the joint between the light emitting element 20 and the radiator 80.

[Modification 3]
In the light emitting device 10 of Example 1, a case has been described in which the heat transfer pin 63 having a head portion at one end on the metal layer 61 side is used. However, the shape of the heat transfer pin 63 is not limited to this.

FIG. 8 is a cross-sectional view of a light emitting device 10C according to modification 3. FIG. 8 is a cross section of the light emitting device 10 shown in FIG. 1, taken along line 2-2.

The light emitting device 10C is different from the light emitting device 10 of Example 1 in that the heat transfer pin 63A of the heat dissipation structure 60C is a straight pin without a head portion.

In the heat dissipation structure 60C, a heat transfer pin 63A is brazed to the surface of a metal layer 61 formed on the lower surface of the substrate 11 using a brazing material 65 such as a silver brazing material.

By using the heat transfer pins 63A which are straight pins, the number (density) of the heat transfer pins 63A bonded to the surface of the metal layer 61 can be increased.

Thereby, the amount of heat that can be conducted by the heat transfer pin 63A can be further increased, and the heat generated from the light emitting element 20 can be more efficiently conducted to the heat radiator 80 and dissipated to the outside. .

In other words, for example, when the light emitting device 10B is assembled into the light emitting device module 100, by increasing the minimum cross-sectional area of the heat path from the light emitting element 20 to the radiator 80, the heat transfer pin portion It is possible to prevent heat from accumulating in the bottleneck.

[Modification 4]
FIG. 9 is a cross-sectional view of a light emitting device 10D according to modification example 4. FIG. 9 is a cross section of the light emitting device 10 shown in FIG. 1, taken along line 2-2.

The light emitting device 10D is different from the light emitting device 10 of Example 1 in that the heat transfer pin 63B of the heat dissipation structure 60D has a long spheroidal tip 63T at the end on the side opposite to the metal layer 61 side.

For example, the tip portion 63T is provided so as to be embedded in the heatsink bonding material 85 within the recess 80F of the heatsink 80 when assembled into the light emitting device module 100.

By having the tip portion 63T, the tip portion 63T serves as an anchor for the heat sink bonding material 85, so that when vertical stress due to vibration or the like is applied to the heat transfer pin 63B or the heat sink 80, the heat transfer pin 63B It becomes possible to prevent the heat sink from coming off from the radiator bonding material 85.

Further, the tip portion 63T can increase the contact area with the radiator bonding material 85 that is bonded to the radiator 80. Therefore, it becomes possible to conduct heat from the heat transfer pin 63B to the heat radiator 80 more efficiently.

Note that the tip portion 63T is not limited to a long spherical shape. The tip portion 63T may have a spherical shape, a crushed shape, or a columnar shape larger than the diameter of the heat transfer pin 63B, for example. The tip portion 63T may have any shape as long as it can increase the contact area with the heatsink bonding material 85 and prevent it from coming off from the heatsink bonding material 85 and, by extension, from the heatsink through hole 80H.

[Modification 5]
FIG. 10 is a cross-sectional view of a light emitting device 10E according to modification 5. FIG. 10 is a cross section of the light emitting device 10 shown in FIG. 1, taken along line 2-2.

The light emitting device 10E differs from the light emitting device 10 of Example 1 in that the heat transfer pin 63C of the heat dissipation structure 60E has a notch 63N in a region near the end on the side opposite to the metal layer 61 side.

For example, the cutout portion 63N is provided at a position where it is embedded in the heatsink bonding material 85 within the recess 80F of the heatsink 80 when it is assembled into the light emitting device module 100.

By having the notch portion 63N, the notch portion 63N acts as an anchor for the heat radiator bonding material 85, thereby preventing heat transfer when vertical stress due to vibration etc. is applied to the heat transfer pin 63C or the heat radiator 80. It becomes possible to prevent the pin 63C from coming off from the radiator bonding material 85.

Furthermore, the notch portion 63N can increase the contact area between the radiator 80 and the radiator bonding material 85 that is bonded to the radiator 80. Therefore, it becomes possible to conduct heat from the heat transfer pin 63C to the heat radiator 80 more efficiently.

Note that the notch portion 63N may be provided on the entire circumference of the heat transfer pin 63C, or may be provided on a part of the outer circumference.

Further, instead of the cutout portion 63N, the surface of the heat transfer pin 63C may be roughened so that the area including the end of the heat transfer pin 63C on the side opposite to the metal layer 61 has a plurality of uneven shapes. .

The heat transfer pin 63C may have any shape as long as it can increase the contact area with the heatsink bonding material 85 and prevent it from coming off from the heatsink bonding material 85 and, by extension, from the heatsink through hole 80H.

Note that the configurations of the respective parts of the embodiments and modifications in this description can be combined as appropriate. For example, in the light emitting device module 100A of Example 2, the light emitting devices 10A to 10E having the heat dissipation structures 60A to 60E described in Modifications 1 to 5 can be incorporated.

As described above, according to the present invention, it is possible to provide a light emitting device and a light emitting device module that can efficiently dissipate heat from a semiconductor light emitting element included in the light emitting device to the outside.

10 Light emitting device 11 Substrate 13 First wiring electrode 15 Second wiring electrode 17 Intermediate wiring 20 Light emitting element 21 Growth substrate 23 Element electrode 25 Element electrode 30 Element bonding layer 40 Wavelength converter 50 Light reflector 60 Heat dissipation structure 61 Metal layer 63 Heat transfer pin 65 Brazing material 70 Circuit board 73, 75 Circuit wiring 78 Device bonding layer 80, 90 Heat sink 81, 91 Heat sink fin 85 Heat sink bonding material

Claims (10)

a substrate made of insulating ceramic and having metal wiring on the top surface;
a light emitting element bonded to the upper surface of the substrate via the metal wiring;
A heat transfer section including a plurality of metal bodies that are electrically insulated from the metal wiring, each of which is bonded to the lower surface of the substrate and protrudes downward from the lower surface of the substrate. Light emitting device. The substrate has a metal layer on a lower surface that is electrically insulated from the metal wiring,
The light emitting device according to claim 1, wherein each of the plurality of metal bodies is bonded to the surface of the metal layer with a brazing material containing metal. The substrate has a metal layer on a lower surface that is electrically insulated from the metal wiring,
The light emitting device according to claim 1, wherein each of the plurality of metal bodies is bonded to the surface of the metal layer by diffusion bonding. 2. The light emitting device according to claim 1, wherein each of the plurality of metal bodies is joined to the substrate by an active brazing material containing metal on the lower surface of the substrate. The light emitting device according to claim 1, wherein each of the plurality of metal bodies has a pin-shaped portion having a cylindrical pin shape. The substrate has an electrode connected to the metal wiring and formed on the lower surface of the substrate,
6. The light emitting device according to claim 1, wherein the plurality of metal bodies are spaced apart from the electrode. a substrate made of insulating ceramic and having metal wiring on its upper surface; a light emitting element bonded to the upper surface of the substrate via the metal wiring; and a light emitting element that is electrically insulated from the metal wiring and each of which a light emitting device comprising: a heat transfer section including a plurality of metal bodies bonded to a lower surface of a substrate and protruding downward from the lower surface of the substrate;
an insulating circuit board having a pair of circuit wires electrically connected to the metal wires of the light emitting device on its upper surface;
A light emitting device module comprising: a radiator disposed on the lower surface of the circuit board;
A plurality of circuit board through-holes are formed in the circuit board at positions corresponding to the plurality of metal bodies of the light emitting device, and penetrate from the top surface to the bottom surface,
Each of the plurality of metal bodies of the light emitting device passes through the plurality of circuit board through-holes of the circuit board and protrudes from the lower surface of the circuit board, and the heat sink and the metal conductor are connected to each other in the protruding portion. A light emitting device module characterized in that the module is bonded using a thermal bonding material. The lower surface of the radiator has a plurality of recesses at positions facing the lower ends of the plurality of metal bodies of the light emitting device,
A plurality of radiator through holes are formed at the bottom of each of the plurality of recesses, and the plurality of radiator through holes that penetrate to the upper surface of the radiator are formed,
Each of the plurality of metal bodies of the light emitting device is inserted through each of the plurality of circuit board through-holes and the plurality of radiator through-holes of the circuit board and into the plurality of recesses of the radiator. Ori,
8. The light emitting device module according to claim 7, wherein each of the plurality of recesses of the radiator is filled with the heat transfer part bonding material. A plurality of recesses are formed on the upper surface of the radiator at positions facing the tips of the plurality of metal bodies of the light emitting device,
Each of the plurality of metal bodies of the light emitting device is inserted through each of the plurality of circuit board through holes of the circuit board and into the plurality of recesses of the radiator,
8. The light emitting device module according to claim 7, wherein each of the plurality of recesses of the radiator is filled with the heat transfer part bonding material. 10. The light emitting device according to claim 7, wherein the plurality of metal bodies of the light emitting device are mutually insulated from the pair of circuit wirings of the circuit board.

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