JP2007012727A - Light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device of excellent heat radiation characteristics by a simple and small configuration. <P>SOLUTION: The light emitting device comprises an LED chip, a first lead frame on which the LED chip is mounted, a second lead frame, and a reflector which covers a part of the first lead frame and a part of the second lead frame, forming a cup-like reflecting surface around the LED chip. The first lead frame is provided with a heat radiation part composed of an exposed part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light emitting device. Specifically, the present invention relates to an improvement in heat dissipation characteristics of a light emitting device using an LED (light emitting diode).

While research and development for increasing the brightness of LEDs has been actively conducted, the problem of heat generation has become apparent as the brightness of LEDs has increased. An example of a structure conventionally employed for the purpose of improving heat dissipation is shown in FIG. In this example, an LED package including an LED chip 70, a reflector 71, and a lead frame 72 is connected to a heat sink 74 via an insulating layer, and a part of the heat of the LED chip 70 is connected via the lead frame 72. Propagate to and dissipate there.
In addition, the structure which has arrange | positioned the heat sink in the horizontal direction of an LED apparatus is also proposed (for example, refer patent document 1).

JP 2000-30521 A

Although the heat radiation effect is exhibited by using the heat sink in the above-described conventional configuration, since the path from the LED chip, which is a heat generation source, to the heat sink is long, the overall thermal resistance value is increased and the heat radiation effect is reduced. In particular, efficient heat propagation is hindered by a member having low thermal conductivity, such as an insulating layer interposed between the lead frame and the heat sink, and heat dissipation efficiency is reduced.
On the other hand, in the above configuration, it is necessary to prepare a heat sink as a separate part, which increases the number of parts, increases the manufacturing cost, and complicates the manufacturing process. Moreover, the enlargement of the apparatus by adoption of a heat sink becomes a problem. Furthermore, the light emitting device cannot be installed with the back side (the side opposite to the LED chip mounting side) as the installation surface, that is, the degree of freedom in mounting the light emitting device is low. On the other hand, if the heat sink is arranged in the lateral direction of the LED device as in the configuration disclosed in Patent Document 1, the degree of freedom of mounting is improved, but the heat dissipation and the number of parts due to the provision of the heat sink as a separate body. The problem is not solved.
Accordingly, an object of the present invention is to provide a light emitting device having excellent heat dissipation characteristics with a simple and small configuration.

In order to achieve the above object, the present invention comprises the following arrangement. That is,
An LED chip;
A first lead frame on which the LED chip is mounted;
A second lead frame;
A reflector that covers a part of the first lead frame and a part of the second lead frame and forms a cup-shaped reflection surface around the LED chip;
In the light emitting device, a heat radiating portion including a portion exposed from the reflector other than the terminal portion and the LED chip mounting portion is formed on the first lead frame.

  In the configuration of the present invention, a part of the lead frame is actively exposed to form a heat radiating portion. As a result, the heat propagated from the LED chip to the lead frame is directly dissipated from the heat dissipating part into the air (without other members interposed). As described above, according to the configuration of the present invention, a part of the lead frame functions as a heat sink to efficiently dissipate heat, resulting in a light emitting device with excellent heat dissipation characteristics. Further, since the heat sink function is added to a part of the lead frame, it is not necessary to provide the heat sink as a separate body, and the configuration is simple and small.

Hereafter, each element which comprises this invention is demonstrated.
(LED)
The kind of LED is not specifically limited, The thing of arbitrary structures can be employ | adopted. For example, an LED including a group III nitride compound semiconductor layer can be used. Group III nitride compound semiconductor is represented by the general formula _{Al X Ga Y In 1-X} -Y N (0 ≦ X ≦ 1,0 ≦ Y ≦ 1,0 ≦ X + Y ≦ 1), AlN, GaN and It includes a so-called binary system of InN, a so-called ternary system of Al _x Ga _1-x N, Al _x In _1-x N, and Ga _x In _1-x N (where 0 <x <1). At least a part of the group III element may be substituted with boron (B), thallium (Tl), etc., and at least a part of the nitrogen (N) is also phosphorus (P), arsenic (As), antimony (Sb) , Bismuth (Bi) or the like. The element functional part of the LED is preferably composed of the binary or ternary group III nitride compound semiconductor.

The group III nitride compound semiconductor may contain an arbitrary dopant. As the n-type impurity, silicon (Si), germanium (Ge), selenium (Se), tellurium (Te), carbon (C), or the like can be used. As the p-type impurity, magnesium (Mg), zinc (Zn), beryllium (Be), calcium (Ca), strontium (Sr), barium (Ba), or the like can be used. Although the group III nitride compound semiconductor can be exposed to electron beam irradiation, plasma irradiation or furnace heating after doping with p-type impurities, it is not essential.
Group III nitride compound semiconductors include metalorganic vapor phase epitaxy (MOCVD), well-known molecular beam crystal growth (MBE), halide vapor phase epitaxy (HVPE), sputtering, ion plating. It can also be formed by a ting method or the like.

  The material of the substrate on which the group III nitride compound semiconductor layer is grown is not particularly limited as long as the group III nitride compound semiconductor layer can be grown. For example, sapphire, gallium nitride, spinel, silicon, silicon carbide, Examples of the substrate material include zinc oxide, gallium phosphide, gallium arsenide, magnesium oxide, manganese oxide, and a group III nitride compound semiconductor single crystal. Among these, it is preferable to use a sapphire substrate, and it is more preferable to use the a-plane of the sapphire substrate.

  The emission color of the LED chip is appropriately selected according to the purpose. For example, it is selected according to a desired emission color such as blue, red, and green. A plurality of LED chips can also be used. In that case, it is possible to combine a plurality of different types of LED chips as well as a combination of the same types of LED chips. For example, LED chips having light emission colors of three primary colors of red, green, and blue are combined. According to such a configuration, a light emitting device capable of emitting any color can be obtained.

(Lead frame)
The light emitting device of the present invention includes a pair of lead frames (first and second lead frames). An LED chip is mounted on one side (first lead frame) of the lead frame. The first lead frame has a portion exposed from the reflector other than a portion where the terminal portion and the LED chip are mounted (LED chip mounting portion). This exposed part functions as a heat radiating part (heat sink). From the viewpoint of improving the heat dissipation characteristics, it is preferable to provide a heat dissipation portion having a surface area as large as possible. Therefore, for example, a heat radiating portion including fins or protrusions (hereinafter collectively referred to as heat radiating fins) is used. In particular, if the heat radiating portion includes a plurality of heat radiating fins, heat can be radiated more efficiently by the air flow generated between the heat radiating fins.

  By bending a part of the lead frame formed into a flat plate shape, a heat radiating fin constituting the heat radiating portion can be formed. Specifically, for example, the radiation fin is formed by bending a part of the edge of the lead frame. As another example, a heat radiation fin may be formed by punching a part of a region to be a heat radiating portion in the lead frame (for example, a U-shape) and standing a region surrounded by the punched portion upright. According to such a method, it is possible to easily produce a heat radiating portion including a plurality of heat radiating fins.

In one embodiment of the present invention, the heat radiation portion is provided on the same plane as the back surface of the reflector or at a position closer to the light emission side of the light emitting device. In such a configuration, since the heat radiating portion does not protrude on the back surface side of the light emitting device, the heat radiating portion does not become an obstacle when mounting the light emitting device with the back surface side as the installation surface, and the light emitting device has a high degree of freedom in mounting. . In the case where the heat radiating fin is formed in the heat radiating portion, the heat radiating fin may be formed so as to protrude toward the light emitting side of the light emitting device.
The size and shape of the heat dissipation part are not particularly limited. Moreover, a heat radiating part may be provided at a plurality of locations to enhance the heat radiating effect.

(Reflector)
The reflector (reflecting member) covers a part of the first lead frame and a part of the second lead frame, and forms a cup-shaped reflecting surface around the LED chip. This reflection surface reflects light emitted from the LED chip in the horizontal or oblique upward direction, and converts it into light in the light extraction direction. The cup shape here refers to a shape surrounding a space where the area of the cross section perpendicular to the optical axis of the LED chip increases continuously or stepwise from the bottom side toward the light extraction direction of the light emitting device. The shape of the reflecting surface is not particularly limited as long as such a condition is satisfied.

The material for forming the reflector is not particularly limited, and an appropriate material can be selected and used from metals, alloys, synthetic resins, and the like. However, the surface facing the LED chip, that is, the reflecting surface is required to be reflective to the light of the LED chip. For example, the reflector can be made of a resin having a high light reflectance such as a white resin. Resin-made reflectors have the advantage of being easy to mold.
On the other hand, when a material that does not have high reflectivity for the light of the LED chip is selected as the material of the reflector, a layer having a high reflectance is formed at least on the surface of the region that becomes the reflective surface. Such a reflective layer can be made of, for example, one or more metals selected from Al, Ag, Cr, Pd, and the like, or alloys thereof. In addition, metal nitrides such as titanium nitride, hafnium nitride, zirconium nitride, and tantalum nitride can also be used as the material of the reflective layer. In particular, the reflective layer is preferably made of Al or an alloy thereof. For the formation of the reflective layer, methods such as vapor deposition, coating, and printing can be employed. In particular, according to the vapor deposition method, a reflective layer having a uniform thickness and a smooth surface can be easily formed. The reflective layer does not necessarily have to be formed on the entire inner peripheral surface of the cup-shaped part, but is emitted laterally or obliquely upward from the LED chip so that the effect of improving the luminous efficiency by the reflective layer is maximized. It is preferable to provide a reflection layer on the entire area irradiated with the light.
The thickness of the reflective layer is not particularly limited as long as it is sufficient to reflect the light from the LED chip, and is, for example, in the range of about 0.1 to about 2.0 μm. Preferably, it is in the range of about 0.5 to about 1.0 μm.
Even when the reflector is manufactured using a material having excellent light reflectivity, a layer made of a highly light-reflective material may be formed on the surface of the portion serving as the reflective surface.

The surface of the reflecting surface is preferably as smooth as possible. This is because specular reflection on the reflecting surface is more likely to occur as the surface becomes smoother, so that the reflection efficiency can be improved and the light emission efficiency can be improved.
The angle of the reflecting surface of the reflector can be designed in consideration of the reflection efficiency in the optical axis direction, and is preferably in the range of 20 ° to 60 ° with respect to the optical axis of the LED chip. More preferably, it is in the range of 40 ° to 50 °.

  By forming the reflector with a material having high thermal conductivity, the heat dissipation characteristics of the light-emitting device can be improved. Examples of the material having high thermal conductivity include metals such as aluminum (Al) and copper (Cu) or alloys thereof. If the reflecting member is made of a material having high thermal conductivity, part of the heat dissipation of the LED chip can be performed via the reflecting member, and the heat dissipation characteristics of the light emitting device are improved.

(Sealing member)
The cup-shaped part of the reflector may be filled with an LED sealing material. The sealing member thus formed is provided mainly for the purpose of protecting the LED chip from the external environment. As a material for the sealing member, it is preferable to adopt a material that is transparent to the light of the LED chip and is excellent in durability, weather resistance, and the like. For example, an appropriate material can be selected from silicone (including silicone resin, silicone rubber, and silicone elastomer), epoxy resin, urea resin, glass and the like in relation to the emission wavelength of the LED chip. When the light of the LED chip contains light in a short wavelength region, ultraviolet degradation is a problem. Therefore, it is preferable to employ a material having high resistance to ultraviolet degradation such as silicone.
As the material of the sealing member, an appropriate material is adopted in consideration of the light transmittance of the LED chip, the hardness in the cured state, the ease of handling, and the like.

  A phosphor can also be contained in the sealing member. By using the phosphor, part of the light from the LED chip can be converted into light having a different wavelength, and the emission color of the light emitting device can be changed or corrected. Any phosphor can be used as long as it can be excited by light from the LED chip, and the light emission color, durability, and the like of the light emitting device are considered in the selection. The phosphor may be uniformly dispersed in the sealing member or may be localized in a part of the region. For example, by localizing the phosphor in the vicinity of the LED chip, the light emitted from the LED chip can be efficiently irradiated onto the phosphor.

A plurality of types of phosphors can be combined and contained in the sealing member. In this case, a phosphor that emits light when excited by light from the LED chip can be used in combination with a phosphor that emits light when excited by light from the phosphor.
A light diffusing material can be contained in the sealing member to promote the diffusion of light within the sealing member, thereby reducing light emission unevenness. In particular, in the configuration using a phosphor as described above, such a light diffusing material is used in order to promote the color mixture of the light from the LED chip and the light from the phosphor and reduce the unevenness of the emission color. preferable.
Hereinafter, the present invention will be described in more detail with reference to examples.

A light emitting device 1 according to an embodiment of the present invention is shown in FIGS. 1 is a perspective view of the light emitting device 1, FIG. 2 is a plan view thereof, and FIG. 3 is a cross-sectional view taken along the line AA of FIG.
The light emitting device 1 roughly includes an LED chip 10, a lead frame 20, a lead frame 30, and a reflector (package) 40.
As shown in FIG. 4, the LED chip 10 has a configuration in which a plurality of semiconductor layers are stacked on a sapphire substrate 11, and has a main emission peak wavelength in the vicinity of 470 nm. The specifications of each layer of the LED chip 10 are as follows.
Layer: Composition p-type layer 15: p-GaN: Mg
Layer 14 including light emitting layer: n-type layer including InGaN layer 13: n-GaN: Si
Buffer layer 12: AlN
Substrate 11: Sapphire

An n-type layer 13 made of GaN doped with Si as an n-type impurity is formed on the substrate 11 via a buffer layer 12. Here, sapphire is used as the substrate 11, but the substrate 11 is not limited to this. Sapphire, spinel, silicon carbide, zinc oxide, magnesium oxide, manganese oxide, zirconium boride, group III nitride compound semiconductor single crystal Etc. can be used. Furthermore, the buffer layer 12 is formed by MOCVD using AlN, but is not limited to this, and GaN, InN, AlGaN, InGaN, AlInGaN, etc. can be used as the material, and the molecular beam crystal can be used as the manufacturing method. A growth method (MBE method), a halide vapor phase epitaxy method (HVPE method), a sputtering method, an ion plating method, an electron shower method, or the like can be used. When a group III nitride compound semiconductor is used as the substrate, the buffer layer can be omitted.
Further, the substrate and the buffer layer can be removed as necessary after the semiconductor element is formed.
Here, the n-type layer 13 is formed of GaN, but AlGaN, InGaN, or AlInGaN can be used.
In addition, although the n-type layer 13 is doped with Si as an n-type impurity, Ge, Se, Te, C, or the like can also be used as the n-type impurity.
The layer 14 including the light emitting layer may include a quantum well structure (multiple quantum well structure or single quantum well structure), and the light emitting element has a single hetero type, a double hetero type, and a homojunction. It may be of a type.

The layer 14 including the light emitting layer may include a group III nitride compound semiconductor layer having a wide band gap doped with Mg or the like on the p-type layer 15 side. This is to effectively prevent the electrons injected into the layer 15 including the light emitting layer from diffusing into the p-type layer 15.
A p-type layer 15 made of GaN doped with Mg as a p-type impurity is formed on the layer 14 including the light-emitting layer. The p-type layer 15 can be AlGaN, InGaN, or InAlGaN, and Zn, Be, Ca, Sr, and Ba can be used as the p-type impurity. After introducing the p-type impurity, the resistance can be lowered by a known method such as electron beam irradiation, heating in a furnace, or plasma irradiation.
In the light emitting device having the above-described configuration, each group III nitride compound semiconductor layer is formed by performing MOCVD under general conditions, a molecular beam crystal growth method (MBE method), a halide vapor phase epitaxy method (HVPE method). ), A sputtering method, an ion plating method, an electron shower method, or the like.

The n-electrode 18 is composed of two layers of Al and V. After the p-type layer 15 is formed, the p-type layer 15, the layer 14 including the light emitting layer, and a part of the n-type layer 13 are removed by etching. It is formed by vapor deposition on the exposed n-type layer 13.
The translucent electrode 16 is a thin film containing gold and is stacked on the p-type layer 15. The p-electrode 17 is also made of a material containing gold, and is formed on the translucent electrode 16 by vapor deposition. After forming each layer and each electrode by the above process, the separation process of each chip is performed.
A reflective layer made of Al, Ag, titanium nitride, hafnium nitride, zirconium nitride, tantalum nitride, or the like may be formed on the back surface of the substrate 11 (the surface on which the semiconductor layer is not formed). By providing the reflective layer, the light directed toward the substrate 11 can be efficiently reflected and converted in the extraction direction, and the light extraction efficiency can be improved. Such a reflective layer can be formed by a known method such as vapor deposition of a forming material.

Both of the lead frames 20 and 30 are made of a copper (Cu) alloy. The lead frame 20 is roughly divided into a terminal portion 21, a region (LED chip mounting portion) 22 on which the LED chip 10 is mounted, and a heat dissipation portion 23. As shown in FIGS. 1 and 3, the lead frame 20 is bent at an angle of about 90 ° toward the optical axis direction of the LED chip 10 between the LED chip mounting portion 22 and the heat radiating portion 23. 23 is positioned on the light extraction side of the light emitting device 1 in an upright state along the side wall of the reflector 40. By adopting such a form of the heat radiating portion 23, the heat radiating portion 23 does not get in the way when the light emitting device 1 is mounted with the back surface side (the bottom surface side of the reflector 40) as an installation surface. It becomes possible.
In this embodiment, the surface area of the heat dissipating part 23 is about ½ of the entire surface area of the lead frame 20. By adopting such a large heat radiating part 23, efficient heat radiation through the heat radiating part 23 becomes possible. The size of the heat radiation part 23 can be set in consideration of the heat radiation efficiency, the size of the light emitting device 1, the amount of heat generated by the LED chip 10, and the like. For example, the heat radiating part 23 can be designed so that the surface area of the heat radiating part 23 is about 1/5 to about 29/30 of the entire surface area of the lead frame 20.

The reflector 40 is made of a white resin, and is shaped so that the inner peripheral surface forming the cup-shaped portion 41 is at a desired angle with respect to the optical axis of the LED chip 10. As a result, a cup-shaped reflecting surface 42 is formed. Note that the reflectivity of the reflector 40 may be enhanced by, for example, plating the surface of the reflector 40.
The cup-shaped portion 41 is filled with a sealing resin 43 (FIG. 3). In this embodiment, an epoxy resin in which a yellow phosphor is dispersed is used as the material of the sealing resin 43.

  Next, a method for manufacturing the light emitting device 1 will be described. First, the LED chip 10 is prepared by the above method. On the other hand, after cutting a metal plate made of a copper alloy, the lead frame 20 having a desired shape is obtained by partially bending the metal plate. The lead frame 30 can also be manufactured by the same method. Next, a white resin is molded on the lead frames 20 and 30 by injection molding to form the reflector 40. The LED chip 10 is mounted on the lead frame with a reflector manufactured in this way using a conductive paste. Subsequently, each electrode of the LED chip 10 is wire-bonded to the corresponding lead frame with a gold wire. Thereafter, the cup-shaped portion 41 of the reflector 40 is molded with a phosphor-containing epoxy resin.

Next, the light emission mode of the light emitting device 1 will be described. First, blue light is emitted from the LED chip 10 upon receiving power. Part of the blue light excites the phosphor in the process of passing through the sealing resin 43 in the cup-shaped portion 41 of the reflector 40, thereby generating yellowish fluorescence. As a result, the light-emitting device 1 emits white light that is a mixed color of blue light and yellow light.
Here, the LED chip 10 generates heat as the light emitting device 1 is driven. Part of the heat generated from the LED chip 10 propagates from the bottom surface side of the LED chip 10 to the lead frame 20 through the conductive paste. The heat propagated to the lead frame 20 spreads from the region immediately below the LED chip 10 to the surroundings, and part of it reaches the heat radiating portion 23. Since the heat radiation part 23 is exposed, the heat reaching the heat radiation part 23 is dissipated from the surface of the heat radiation part 23 into the surrounding air. In this way, in the light emitting device 1, active heat radiation is performed by a part of the lead frame 20, that is, the heat radiation portion 23. Moreover, since the heat radiating portion 23 having a large surface area is provided as described above, a high heat radiating effect is exhibited.
As described above, in the light emitting device 1, the heat of the LED chip 10 is efficiently dissipated by using the lead frame 20 as a main heat dissipation path, and as a result, the temperature rise of the LED chip 10 is mitigated. As a result, the light emitting device is excellent in driving stability and reliability, and at the same time, a long life is achieved. In addition, a heat dissipation function is added to a part of the lead frame instead of separately providing a heat dissipation member, so that a simple and small device can be obtained.

Another embodiment of the present invention is shown in FIGS. FIG. 5 is a perspective view of the light emitting device 2, and FIG. 6 is a plan view showing a state in the middle of manufacturing the lead frame 50 used in the light emitting device 2. In the following description, the same members as those of the light emitting device 1 of the above embodiment are denoted by the same reference numerals, and the description thereof is omitted.
The heat dissipation portion 53 of the lead frame (lead frame on which the LED chip 10 is mounted) 50 used for the light emitting device 2 includes three fins (first fin 54, second fin 55, and third fin 56). These three fins are aligned in a line at equal intervals, and each fin is connected on both sides. Further, through holes 54a to 56a exist between the fins, respectively.
The heights of the fins 54 to 56 are not particularly limited, but in this embodiment, the heights of the fins 54 to 56 are such that the upper surface of the reflector 40 and the upper surfaces of the fins 54 to 56 are located on substantially the same plane. It was set. With such a configuration, a small light emitting device is formed which does not have an upward and downward protrusion which is inconvenient in terms of handling. In addition, it is possible to mount the light emitting device 2 with a high degree of freedom using the back side as an installation surface.

  The lead frame 50 can be manufactured by the following procedure. First, after cutting a metal plate made of a copper alloy, it is punched into a U-shape at three locations (indicated by dotted lines in FIG. 6), and then the portion surrounded by the punched portion is its root (indicated by a one-dot chain line in FIG. 6). It is molded by bending and standing upright. After preparing the lead frame 50 in this manner, the reflector 40 is formed, the LED chip 10 is mounted, and the like in the same procedure as in the case of the light emitting device 1 to obtain the light emitting device 2.

In the lead frame 50 of the light emitting device 2, part of the heat of the LED chip 10 that reaches the heat radiating part 53 via the LED chip mounting part 52 is radiated on the surface of the first fin 54. Further, a part of the heat reaching the heat radiating portion 53 propagates to the second fin 55 and the third fin 56 through the connecting portions 57 and 58 of the heat radiating portion 53, and the same heat radiating action is exhibited. Thus, the connection parts 57 and 58 function as a heat pipe, and heat is transmitted to the fins 54 to 56 and heat is radiated on the fin surfaces. It should be noted that the surface of the connecting portions 57 and 58 also has a heat radiation effect as with the fin surface. On the other hand, by providing a plurality of fins, it is possible to expect a heat dissipation effect due to the air flow between the fins. In addition, since air can pass through the through holes formed between the fins, the movement of air near the surface of each fin is promoted, and high heat dissipation efficiency can be obtained.
As described above, in the light emitting device 2, high drive stability or reliability can be obtained by actively and efficiently radiating heat using a part of the lead frame. The light emitting device 2 also has a simple and small configuration by providing a heat radiating function to a part of the lead frame, instead of separately providing a heat radiating member.

Yet another embodiment of the present invention is shown in FIGS. 7 is a perspective view of the light emitting device 3, and FIG. 8 is a plan view thereof. In the following description, the same members as those of the light emitting device 1 of the above embodiment are denoted by the same reference numerals, and the description thereof is omitted.
In the lead frame (lead frame on the side where the LED chip 10 is mounted) 60 used in the light emitting device 3, the heat radiating portions 63 are provided at two locations. The two heat dissipating parts 63 are provided at symmetrical positions around the LED chip mounting part 62. A plurality of fin-like protrusions 64 are formed on the heat dissipation part 63. In this embodiment, the number of fin-like protrusions 64 formed per heat radiating portion is seven. The height of the fin-like projection 64 is about 0.3 mm, for example. In the lead frame 60, all parts other than the fin-like protrusions 64 have the same thickness (about 0.15 mm).

  The lead frame 60 can be manufactured by cutting a deformed rolled plate into a desired shape and then bending the terminal portion 61. Alternatively, the lead frame 60 can be manufactured by using press working.

  In the light emitting device 3, (1) the heat dissipating part 63 is provided on the lead frame 60 and the heat dissipating parts 63 are disposed apart from each other, and (2) the heat dissipating part is formed by forming a plurality of protrusions on each heat dissipating part 63. In addition to increasing the surface area of the projections, the fins are shaped like fins to efficiently dissipate heat by airflow, so that a very high heat dissipating effect is exhibited and high driving stability or reliability is obtained. . Note that the light emitting device 3 also has a simple and small configuration by providing a heat radiating function to a part of the lead frame instead of separately providing a heat radiating member.

  The light emitting device of the present invention can be used, for example, as a light source for vehicle interior lighting, a light source for indoor lighting, and the like.

The present invention is not limited to the description of the embodiments and examples of the invention described above. Various modifications may be included in the present invention as long as those skilled in the art can easily conceive without departing from the description of the scope of claims.
The contents of papers, published patent gazettes, patent gazettes, and the like specified in this specification are incorporated by reference in their entirety.

It is a perspective view of the light-emitting device 1 which is an Example of this invention. 2 is a plan view, and FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2 is a plan view of the light emitting device 1. FIG. It is sectional drawing in the AA line position of FIG. 3 is a plan view showing a configuration of an LED chip used in the light emitting device 1. FIG. It is a perspective view of the light-emitting device 2 which is the other Example of this invention. FIG. 6 is a plan view showing a state in the middle of manufacturing a lead frame 50 used in the light emitting device 2. It is a perspective view of the light-emitting device 3 which is further another Example of this invention. 3 is a plan view of the light emitting device 3. FIG. It is sectional drawing which shows the structure of the conventional light-emitting device.

Explanation of symbols

1, 2, 3 Light-emitting device 10 LED chip 20, 30, 50, 60 Lead frame 23, 53, 63 Lead frame heat radiation part 40 Reflector 41 Reflector cup-shaped part 42 Reflective surface 54 to 56 Heat radiation fin 64 Fin-like projection part

Claims (5)

An LED chip;
A first lead frame on which the LED chip is mounted;
A second lead frame;
A reflector that covers a part of the first lead frame and a part of the second lead frame and forms a cup-shaped reflection surface around the LED chip;
A light emitting device in which a heat radiating portion including a portion exposed from the reflector other than the terminal portion and the LED chip mounting portion is formed on the first lead frame.   The light emitting device according to claim 1, wherein the heat dissipating part includes a fin or a protrusion.   The light emitting device according to claim 1, wherein the heat dissipating part is provided at a plurality of locations.   The light emitting device according to any one of claims 1 to 3, wherein the heat dissipating part is disposed on the same plane as the back surface of the reflector or on the light emission side of the light emitting device.   The light emitting device according to claim 1, wherein the heat dissipating part includes a fin formed by bending a part of the flat first lead frame.

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