JP2002223006A - Reflection type light emitting diode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reflection type light emitting diode which is resistant to temperature change, can be miniaturized easily and is excellent in heat dissipating properties. SOLUTION: In the reflection type light emitting diode 1, a light emitting element 2 is mounted on the lower surface of one lead 3a out of a pair of leads 3a, 3b for supplying power to the light emitting element 2, the other lead 3b is connected electrically with the light emitting element 2 by bonding using wire 4, a recessed type reflecting mirror 5 formed by press-working an aluminum plate is fixed, and sealing is performed by using transparent epoxy resin 6. A plane form of a radiating part 7 is molded on the rear of the light emitting element 2. The lead 3a on which the light emitting element 2 is mounted is arranged adjacently to a plane edge part 5a of the reflecting mirror 5, interposing a ring type thin plate insulating member 8 of 0.1 mm in thickness, so that heat of the light emitting element 2 travels the plane edge part 5a from the lead 3a and escapes from the whole of the reflecting mirror 5. As a result, a reflection type LED which is very excellent in heat dissipating properties is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reflection type light emitting diode (hereinafter referred to as "reflection type LED") capable of obtaining high external radiation efficiency by reflecting light emitted from a light emitting element with a concave reflecting mirror. Also abbreviated.) In this specification, the LED chip itself is referred to as a “light emitting element”, and the entire light emitting device including an optical device such as a package resin or a lens system on which the LED chip is mounted is referred to as a “light emitting diode” or “LED”. I do.

[0002]

2. Description of the Related Art A light emitting element is mounted on a lead, and these are sealed with a resin. A light emitting surface side of the light emitting element is molded with a reflecting surface, and a light emitting surface is molded on a back side of the light emitting element. 2. Description of the Related Art A reflection type light emitting diode (reflection type LED) in which a reflection mirror is formed by depositing a metal such as silver on a resin surface is known.

[0003] As an example of such a reflection type LED, FIG. 8 shows a light emitting diode described in Japanese Patent Application Laid-Open No. 10-144966. FIG. 8 is a longitudinal sectional view showing the entire structure of a conventional reflection type light emitting diode.

[0004] As shown in FIG.
At 61, the light emitting element 62 is mounted on the lower surface of one of the pair of leads 63a and 63b,
The other lead 63b and the light emitting element 62 are electrically connected by bonding with a wire 64. The lead part is sealed with a transparent epoxy resin 66, and a radiation surface shape 66a is formed on the back side of the light emitting element 62. A reflective surface shape 66b is molded on the light emitting surface side of the element 62. By depositing silver on the reflecting surface shape 66b, the reflecting mirror 65 is formed.
Are formed.

The reflection type LED 61 having such a structure does not lower the external radiation efficiency unlike the lens type LED even if the light collecting degree is increased, and is arranged by the reflecting mirror 65 having a solid angle of about 2.pi. Since high external radiation characteristics independent of optical characteristics can be obtained, it is particularly suitable for focused external radiation. Also, since the upper and lower optical surfaces can be easily manufactured simultaneously by transfer molding, it is suitable for mass production.

[0006]

However, such a reflective LED 61 is vulnerable to temperature changes because the thermal expansion coefficients of the sealing resin and the vapor-deposited metal are significantly different, and the metal material of the reflecting mirror 65 is separated from the sealing resin 66. As a result, wrinkles are generated on the reflecting surface, and the function as a reflecting mirror is lost. For this reason, there has been a problem that it cannot cope with a reflow furnace or the like for mounting a substrate having a large temperature change.

[0008] As shown in FIG. 8, in order to secure a space for masking to prevent short-circuiting of the leads 63 a, 63 b during metal deposition, the leads 63 a, 6
3b to bend vertically to reinforce the ends.
The lead-out portions 67a and 67b of 5 mm have to be provided, and therefore, the package size of the reflection type LED 61 is required to be extra by 2 to 3 mm, and there is also a problem that miniaturization is limited.

In addition, LEDs are required to have higher heat dissipation. Generally, when the temperature of the light emitting element increases, the light output of the light emitting element decreases, and the life characteristics also decrease. Further, for example, when a large current is applied to a light emitting element, heat dissipation is particularly required. For this reason, the reflection type LED having the configuration like the LED 61 has insufficient heat radiation.

Accordingly, an object of the present invention is to provide a reflective LED which is resistant to temperature changes, can be easily miniaturized, and has excellent heat dissipation.

[0010]

According to a first aspect of the present invention, there is provided a reflection type light emitting diode in which a light emitting element, a pair of leads for supplying power to the light emitting element, and a light emitting surface of the light emitting element are opposed to each other. A concave reflecting mirror, and a radiating portion on the back side of the light emitting element, wherein one of the pair of leads on which the light emitting element is mounted and the reflecting mirror are arranged in contact or close proximity, The one lead and / or the other lead of the pair of leads and the reflecting mirror are insulated from each other, and the pair of leads and the reflecting mirror are made of a material having high thermal conductivity. It has enough heat capacity to spread the generated heat.

In the reflection type light emitting diode having such a configuration, one of the leads on which the light emitting element is mounted and the reflecting mirror are in contact with or close to each other, so that the heat of the light emitting element is transferred from a material having high thermal conductivity. From one lead, which has a sufficient heat capacity to diffuse the heat generated by the light emitting element, to a reflector made of a material having high thermal conductivity and having a sufficient heat capacity to diffuse the heat generated by the light emitting element Since the heat is transmitted and radiated from the entire reflecting mirror, the heat radiation is extremely good. Since one or both of the one lead and the other lead are insulated from the reflecting mirror, there is no fear that one of the leads and the other lead are short-circuited via the reflecting mirror.

In addition, a concave reflecting mirror facing the light emitting surface side of the light emitting element has a high reflectivity, a high external radiation efficiency, and a high degree of freedom in designing light emitting characteristics such as light distribution characteristics. Therefore, a high luminous intensity can be realized.

Further, the use of a reflecting mirror formed of a material having high thermal conductivity makes it resistant to temperature changes. The function as a reflector is not lost. For this reason, a reflow furnace for surface mounting can be used, and it can be used as a surface mounting component without any limitation, so that it is suitable as a reflective LED mounted in a large number. In addition, in the reflection type LED having such a configuration, it is not necessary to take an extra space as a lead lead-out portion, so that it is suitable for miniaturization.

In this way, it is resistant to temperature changes,
It is easy to reduce the size and has excellent heat dissipation.
ED.

According to a second aspect of the present invention, there is provided a reflection type light emitting diode, comprising: a light emitting element;
A pair of leads, a concave reflecting mirror facing the light emitting surface side of the light emitting element, a radiating section on the back side of the light emitting element, and a light transmitting material for sealing; One of the leads on which the light emitting element is mounted and the reflecting mirror are in contact with or close to each other, and the other lead of the one lead and / or the pair of leads;
The reflecting mirror is insulated, the pair of leads and the reflecting mirror are made of a material having high thermal conductivity, have a heat capacity sufficient to diffuse the heat generated by the light emitting element, The light emitting element, a part of the pair of leads, and the reflecting mirror are sealed and molded with the light transmitting material.

In the reflective light-emitting diode having such a configuration, one of the leads on which the light-emitting element is mounted and the reflecting mirror are in contact with or close to each other, so that heat of the light-emitting element is transferred from a material having high thermal conductivity. From one lead, which has a sufficient heat capacity to diffuse the heat generated by the light emitting element, to a reflector made of a material having high thermal conductivity and having a sufficient heat capacity to diffuse the heat generated by the light emitting element Since the heat is transmitted and radiated from the entire reflecting mirror, the heat radiation is extremely good. Since one or both of the one lead and the other lead are insulated from the reflecting mirror, there is no fear that one of the leads and the other lead are short-circuited via the reflecting mirror.

Further, a concave reflecting mirror facing the light emitting surface side of the light emitting element has a high reflectivity, a high external radiation efficiency, and a high degree of freedom in designing light emitting characteristics such as light distribution characteristics. Therefore, a high luminous intensity can be realized. further,
Because the light emitting element is sealed with a light transmitting material,
The light output from the light emitting element is about twice that in the case where the light is directly emitted into the air, and the amount of external radiation can be further increased. Further, since the light emitting element is sealed, deterioration due to moisture is prevented, and a highly reliable reflective LED is obtained.
Furthermore, since the light emitting element, a part of the lead, and the reflecting mirror are sealed and molded with the light transmitting material, the radiating portion emits light by mirror-finishing the inner wall surface of the sealing mold. The surface roughness of the portion is also at the optical level and is formed as an optical surface. As a result, the light reflected by the reflector is radiated from the radiating portion as it is with high external radiation efficiency without scattering at the radiating portion interface.

Further, the final step is a step of merely setting the members in a mold and sealing the resin, and can be easily produced by using existing production equipment, and mass production of the reflective LED can be achieved. . Furthermore, by using a reflector formed of a material having high thermal conductivity, the mirror is resistant to temperature changes. There is no loss of functionality. For this reason, a reflow furnace for surface mounting can be used, and it can be used as a surface mounting component without any restrictions.
It becomes suitable as. Further, the reflection type L having such a configuration is used.
The ED does not require an extra space as a lead lead-out portion, and thus is suitable for miniaturization.

In this way, it is resistant to temperature changes,
It is easy to reduce the size, the external radiation efficiency is high, the mass productivity is excellent, and the reflection type LED is excellent in heat dissipation.

According to a third aspect of the present invention, in the reflective light emitting diode according to the first or second aspect, one of the pair of leads is provided with the light emitting element mounted on a peripheral portion of the reflecting mirror. A heat transfer portion for transmitting heat from the lead is formed.

As described above, by forming the heat transfer portion on the peripheral edge of the reflecting mirror, the contact area or proximity area with one lead on which the light emitting element is mounted is increased, and the heat of the light emitting element is transferred to one lead. The reflection type LE is more excellent in heat dissipation because it can be transmitted to the reflecting mirror through the
D.

Further, the use of a reflecting mirror made of a material having high thermal conductivity is resistant to temperature changes, and is reflected by the occurrence of wrinkles and the like due to temperature changes as in a reflecting mirror or the like on which metal is deposited on a resin surface. It does not lose its function as a mirror. For this reason, it is possible to support a reflow furnace for surface mounting, and it can be used as a surface mounting component without any limitation, so that it is suitable as an LED to be mounted in a large amount. In addition, in the reflection type LED having such a configuration, it is not necessary to take an extra space as a lead lead-out portion, so that it is suitable for miniaturization.

In this way, it is resistant to temperature changes,
It is easy to reduce the size, and the reflection type LED is excellent in heat dissipation.

According to a fourth aspect of the present invention, in the reflective light emitting diode according to any one of the first to third aspects, the pair of leads and the reflecting mirror are formed of a metal plate. It is.

The metal plate has high thermal conductivity and excellent workability, so that a concave reflecting mirror can be easily formed. Then, by transmitting the heat of the light emitting element from the one lead made of the metal plate to the reflecting mirror, heat can be radiated from the entire reflecting mirror, and a reflection type LED having extremely excellent heat dissipation can be obtained.

Furthermore, the use of a reflector formed of a metal plate allows the film to withstand temperature changes, and functions as a reflector due to the occurrence of wrinkles due to temperature changes as in the case of a metal-deposited reflector or the like on a resin surface. Never lose.
For this reason, a reflow furnace for surface mounting can be used, and it can be used as a surface mounting component without any limitation, so that it is suitable as a reflective LED mounted in a large number. In addition, in the reflection type LED having such a configuration, it is not necessary to take an extra space as a lead lead-out portion, so that it is suitable for miniaturization.

In this way, it is resistant to temperature changes,
It is easy to reduce the size and has excellent heat dissipation.
ED.

According to a fifth aspect of the present invention, in the reflective light emitting diode according to any one of the first to fourth aspects, the reflecting mirror is formed of an aluminum plate.

Since the aluminum plate is a material that can be easily pressed, it can be easily formed into a reflecting mirror by pressing. Further, since an aluminum plate having an extremely high linear reflectance can be easily obtained, a reflecting mirror having a high reflectance can be easily produced. Since the heat conductivity is high, the heat of the light emitting element is transmitted from one of the leads to the aluminum-made reflecting mirror, so that heat can be radiated from the entire reflecting mirror. Aluminum has a high reflectance in the wavelength region from visible light to ultraviolet light, and does not require plating when used as a reflecting mirror. In particular, when an ultraviolet light emitting element is used as the light emitting element, since the reflectance of silver is extremely low in the ultraviolet region, aluminum reflecting mirrors have high ultraviolet reflection which cannot be obtained by the widely used silver plating process. Rate can be obtained.

The use of a reflecting mirror formed of an aluminum plate is resistant to temperature changes, and functions as a reflecting mirror due to the occurrence of wrinkles due to temperature changes as in a reflecting mirror or the like in which metal is deposited on a resin surface. Never lose. For this reason, a reflow furnace for surface mounting can be used, and it can be used as a surface mounting component without any limitation, so that it is suitable as a reflective LED mounted in a large number. In addition, in the reflection type LED having such a configuration, it is not necessary to take an extra space as a lead lead-out portion, so that it is suitable for miniaturization.

In this way, it is resistant to temperature changes,
It is easy to reduce the size, has a high reflectance, can be applied to an ultraviolet light emitting element, and is a reflective LED excellent in heat dissipation.

According to a sixth aspect of the present invention, in the reflective light emitting diode according to the fourth or fifth aspect, the reflecting mirror has a surface subjected to a light-transmitting insulating treatment.

That is, in the reflection type LED of the present invention, the reflection mirror is obtained by subjecting a surface of a metal plate to a light-transmitting insulation treatment (oxidation treatment). By forming the translucent insulating metal oxide on the surface in this manner, the surface of the reflecting mirror can be made insulative without lowering the reflectance of the reflecting mirror. Even if both are brought into contact with the reflecting mirror, there is no short circuit between one lead and the other lead. This facilitates the manufacture of a reflective LED using a metal reflector. Further, since one of the leads can be brought into contact with the reflecting mirror, the heat transfer property is improved, and the heat dissipation property is further improved.

The use of a reflecting mirror formed of a metal plate makes it resistant to temperature changes, and functions as a reflecting mirror due to the occurrence of wrinkles due to temperature changes as in a reflecting mirror or the like in which metal is deposited on a resin surface. Never lose.
For this reason, a reflow furnace for surface mounting can be used, and it can be used as a surface mounting component without any limitation, so that it is suitable as a reflective LED mounted in a large number. In addition, in the reflection type LED having such a configuration, it is not necessary to take an extra space as a lead lead-out portion, so that it is suitable for miniaturization.

In this way, it is resistant to temperature changes,
It is easy to reduce the size, and the reflection type LED is excellent in heat dissipation.

[0036]

Embodiments of the present invention will be described below.

First Embodiment First, a first embodiment of the present invention will be described with reference to FIG. FIG. 1A is a plan view showing the entire configuration of the reflective light emitting diode according to the first embodiment of the present invention, and FIG.
FIG. 2 is a longitudinal sectional view showing a section taken along line AA.

As shown in FIG. 1, the reflective light emitting diode 1 of the first embodiment emits light on the lower surface of one of the leads 3a, 3b for supplying power to the light emitting element 2. The element 2 is mounted, the other lead 3b and the light emitting element 2 are electrically connected by bonding with a wire 4 and a concave reflecting mirror 5 formed by pressing an aluminum plate is attached. Are used to seal the entire reflecting mirror 5. At the same time, the planar shape of the radiation section 7 is molded on the back side of the light emitting element 2. Light emitting element 2
Emits green light. The leads 3a and 3b are formed by plating a 0.3 mm thick copper alloy plate with silver, and the sealing with the transparent epoxy resin 6 is performed by potting molding.

The reflecting mirror 5 is made of an aluminum plate having a linear reflectance of 85% and a thickness of 0.2 mm manufactured by a method in which rolling roll marks are less likely to be formed during rolling, and consideration is given to maintaining this surface roughness. The light-emitting element 2 is processed into a concave shape having a solid angle of about 2πstrad and a substantially paraboloid of revolution centered on the light-emitting element 2. Therefore, all the light emitted from the light emitting element 2 becomes reflected light parallel to the axis of the paraboloid of revolution by the reflecting mirror 5 and is emitted from the radiating portion 7 on the back surface of the light emitting element 2.

A flat edge portion 5a as a heat transfer portion is formed around the aluminum cup on which the reflecting mirror 5 is formed.
A ring-shaped thin insulating material 8 having a thickness of 0.1 mm is arranged on the flat edge portion 5a so as to surround the edge of the reflecting mirror 5.
One lead 3a is arranged on the thin insulating material 8 such that two protruding portions 3c of the one lead 3a are located, and the one lead 3a is sandwiched by the thin insulating material 8 having a thickness of 0.1 mm. And the plane edge 5a of the reflecting mirror 5 are close to each other. By providing the two protruding portions 3c in this manner, the area of the vicinity of one of the leads 3a and the planar edge 5a of the reflecting mirror 5 is increased, and the heat dissipation is further increased.

Since the thin insulating material 8 has a ring shape surrounding the edge of the reflecting mirror 5, the other lead 3b is also insulated from the flat edge 5a of the reflecting mirror 5. In addition, since the thin plate insulating material 8 has a ring shape, the reflection type L
There is an advantage that the manufacture of the ED1 becomes easy. Note that the thin insulating material 8 does not necessarily have to be a ring shape surrounding the edge of the reflecting mirror 5, and the two protruding portions 3 c of one lead 3 a or the other lead 3 b and the planar edge 5 of the reflecting mirror 5 may be used.
What is necessary is just to insulate from a.

In the reflection type LED 1 having such a structure,
Since almost the entire luminous flux emitted from the light emitting element 2 can be controlled and externally radiated, the external radiation efficiency is high and the degree of freedom in designing the light radiation characteristics such as the light distribution characteristics can be increased. Therefore, a high luminous intensity can be realized. Further, the light emitting element 2 is made of a sealing resin 6.
Is located on the surface of the sealing resin 6, and the lead 3a on which the light emitting element 2 is mounted is connected to the planar edge 5a of the reflecting mirror 5. The heat generated by the light emitting element 2 is transmitted from the lead 3a to the reflecting mirror 5 through the plane edge 5a. Since the reflecting mirror 5 has a high thermal conductivity and a thickness having a sufficient heat capacity, the heat of the light emitting element 2 is released from the entire reflecting mirror 5. For this reason, the reflection type LED has extremely excellent heat dissipation.

Further, the optical surface requiring resin molding is only the radiating portion 7, and the transfer molding and the potting molding can be easily performed by a process of merely setting a member in a mold and sealing with resin. Mass production can be achieved. Further, the degree of freedom of the manufacturing method is increased, so that the degree of freedom of the sealing material 6 is increased, and it is possible to select the sealing material 6 according to the use such as a material having a small stress, a material having high heat resistance, and a material having excellent weather resistance. Becomes

Further, in the first embodiment, since the concave reflecting mirror 5 formed by pressing an aluminum plate is used, the reflecting mirror 5 is resistant to temperature change and has a metal surface deposited on a resin surface. As a result, the function as a reflecting mirror is not lost due to the occurrence of wrinkles due to a temperature change. For this reason, a reflow furnace for surface mounting can be used, and it can be used as a surface mounting component without any limitation, so that it can be suitable as a reflective LED to be mounted in a large amount.

Although the number of components is increased, the vapor deposition step can be omitted, and it is not necessary to pay attention to the subsequent steps, so that the resin sealing step can be simplified and the yield can be increased.
In addition, there is no need to consider lead short-circuit prevention processing at the time of vapor deposition and to secure a reinforcing portion at the time of bending of the lead, so that there is an effect that the lead-out interval can be reduced.

Further, since the reflecting mirror 5 is formed by simply pressing an aluminum plate material having a high linear reflectance by pressing, not only the plating process is not required, but also consideration for plating corrosion is not required. Management can be simplified. Aluminum materials are widely used materials and are easily available.

As described above, the reflection type LE of the first embodiment is
D1 has high external radiation efficiency, has resistance to temperature change,
It is easy to manufacture and easy to miniaturize, and extremely excellent in heat dissipation.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 2A shows a second embodiment of the present invention.
FIG. 1B is a plan view showing the entire configuration of the reflection type light emitting diode according to the first embodiment, and FIG. FIG. 3 is a longitudinal sectional view showing a section of the reflective light emitting diode according to the second embodiment of the present invention, taken along line CC of FIG. 2A. FIG. 4 is a longitudinal sectional view showing a modification of the reflective light emitting diode according to the second embodiment of the present invention. FIG. 5 is a longitudinal sectional view showing another modification of the reflective light emitting diode according to the second embodiment of the present invention.

As shown in FIG. 2, the reflective light emitting diode 11 of the second embodiment emits light on the lower surface of one of the leads 13a and 13b for supplying power to the light emitting element 12. The element 12 is mounted, the other lead 13b and the light emitting element 12 are electrically connected by bonding with a wire 14, and a concave reflecting mirror 15 formed by pressing an aluminum plate is attached. Are used to seal the entire reflecting mirror 15. at the same time,
The planar shape of the radiation section 17 is molded on the back side of the light emitting element 12. The light emitting element 12 emits green light. The leads 13a, 13b are formed by plating a 0.3 mm thick copper alloy plate with silver, and the sealing with the transparent epoxy resin 16 is performed by potting molding.

The reflecting mirror 15 is made of an aluminum plate having a linear reflectance of 85% manufactured by a method in which rolling roll marks are less likely to be formed during rolling. Considering that the surface roughness is maintained, the reflecting mirror 15 is used for the light emitting element 12. Has a solid angle of about 2πstrad,
It is processed into a concave shape having a substantially paraboloid of revolution with the light emitting element 12 as a focal point. Therefore, all the light emitted from the light emitting element 12 becomes reflected light parallel to the axis of the paraboloid of revolution by the reflecting mirror 15 and is emitted from the radiating portion 17 on the back surface of the light emitting element 12.

A flat edge 15a as a heat transfer portion is formed around the aluminum cup on which the reflecting mirror 15 is formed, and one lead provided with the flat edge 15a and two projecting portions 13c. 13a is in direct contact with
Heat transfer is improved. Further, by providing the two protrusions 13c in this manner, the contact area between one lead 13a and the plane edge 15a of the reflecting mirror 15 is increased, and the heat dissipation is further increased.

As described above, one lead 13a and the reflecting mirror 1
5, the other lead 13b needs to be insulated from the reflecting mirror 15 and the plane edge 15a. Reflective LED 11 of Embodiment 2
In this case, as shown in FIGS. 2A and 3, a notch 15b is provided in a part of the reflecting mirror 15 and the planar edge 15a, and the other lead 13b is provided in the notch 15b.
The other lead 13b and the reflecting mirror 15
And the plane edge 15a. By providing the notch 15b in this manner, the other lead 13b
Has the advantage that insulation can be ensured without any processing.

Next, a modification of the reflection type LED of the second embodiment will be described with reference to FIG. The reflective LED 21 according to the modification of the second embodiment shown in FIG. 4 also has the same configuration as the reflective LED 11 shown in FIG.
One lead 23a on which the light emitting element 22 is mounted is in direct contact with the planar edge 25a of the aluminum reflecting mirror 25. On the other hand, the other lead 23b bonded to the light emitting element 22 by the wire 24 has a concave portion 23c formed by hollowing the lower surface of a portion corresponding to the planar edge portion 25a of the reflecting mirror 25. Thereby, the other lead 23b is insulated without contacting the planar edge 25a of the reflecting mirror 25.

Next, another modified example of the reflection type LED of the second embodiment will be described with reference to FIG. Reflective LE according to another modification of the second embodiment shown in FIG.
D31 also has one lead 33 on which the light emitting element 32 is mounted, similarly to the reflection type LED 11 shown in FIG.
“a” is in direct contact with the plane edge 35 a of the aluminum reflecting mirror 35. On the other hand, the light emitting element 32 and the wire 34
The other lead 33b bonded by the reflecting mirror 3
5, a bridge portion 33c is formed by bending upward at a portion corresponding to the flat edge portion 35a. Thus, the other lead 33b is insulated without contacting the planar edge 35a of the reflecting mirror 35.

As described above, the reflection type LED 21 of the modification shown in FIG. 4 and the reflection type L of another modification shown in FIG.
In the ED 31, the other leads 23b and 33b must be processed, but instead, the reflecting mirrors 25 and 35 are used.
Can be pressed into a normal form, so that the reflecting mirrors 25 and 3 can be used.
5 can stabilize the molding accuracy of the reflecting surface.

The reflection type LED 11, 21, 21, 3 having such a structure.
In 1, the external light can be emitted by controlling substantially the entire luminous flux emitted by the light emitting elements 12, 22, and 32, so that the external radiation efficiency is high and the degree of freedom in designing light emission characteristics such as light distribution characteristics can be increased. Therefore, a high luminous intensity can be realized.
Further, the light emitting elements 12, 22, 32 are formed of the sealing resin 16, 2,
6, 36, the light emitting elements 12, 22, 32
Lead 13a, 23a, 33a which is a heat radiation path of
Are also located on the surface of the sealing resin 16, 26, 36, and one of the leads 13a, 23a, 33a is
5 and 35, which are in direct contact with the plane edges 15a, 25a, and 35a, and are transmitted from the leads 13a, 23a, and 33a to the plane edges 15a, 25a, and 35a, and are reflected by the reflection mirrors 15, 2.
Since the heat of the light emitting elements 12, 22, and 32 is released from the whole of the elements 5, 35, the reflection type LED has extremely excellent heat dissipation.

The optical surfaces that require resin molding are only the radiating portions 17, 27, and 37. Both transfer molding and potting molding can be easily performed by simply setting the members in a mold and sealing the resin. Yes, LE
D can be mass-produced. Further, due to the improvement in the degree of freedom of the manufacturing method, the degree of freedom of the sealing materials 16, 26, and 36 is increased, and the sealing materials according to the application, such as a material having a small stress, a material having high heat resistance, and a material having excellent weather resistance, are used. Selection becomes possible.

Further, in the second embodiment, the concave reflecting mirrors 15, 2 formed by pressing an aluminum plate are used.
By using 5,35, it has resistance to temperature change,
The function as a reflecting mirror is not lost due to the occurrence of wrinkles or the like due to a temperature change as in a reflecting mirror or the like in which metal is deposited on the resin surface. For this reason, a reflow furnace for surface mounting can be used, and it can be used as a surface mounting component without any limitation, so that it can be suitable as a reflective LED to be mounted in a large amount.

As described above, the reflection type LE according to the second embodiment is used.
D11, 21, 31 have high external radiation efficiency, are resistant to temperature changes, can be easily miniaturized, and have extremely excellent heat dissipation.

Third Embodiment Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 6A is a plan view showing the entire configuration of the reflective light emitting diode according to the third embodiment of the present invention, and FIG.
FIG. 3 is a longitudinal sectional view showing a section taken along line DD.

As shown in FIG. 6, the reflection type light emitting diode 41 according to the third embodiment has one of the leads 43a and 43b for supplying power to the light emitting element 42 that emits ultraviolet light. The light emitting element 42 is mounted on the lower surface, and the other lead 43 b and the light emitting element 42 are connected to the wire 4.
A lead portion electrically connected by bonding at 4,
A concave reflecting mirror 45 formed by pressing an aluminum plate
And a glass plate 46 as a radiation part.

As in the first and second embodiments, an aluminum plate having a linear reflectance of 85% manufactured by a method in which a roll roll scarcely occurs during rolling is used as in the first and second embodiments, and this is used to maintain this surface roughness. Considering that the light-emitting element 42 has a solid angle of about 2πstrad, the light-emitting element 42 is processed into a substantially paraboloidal concave shape having a focal point at the light-emitting element 42. Therefore, all the ultraviolet light emitted from the light emitting element 42 becomes reflected light parallel to the axis of the paraboloid of revolution by the reflecting mirror 45, and is emitted from the radiation part 46 of the glass plate on the back surface of the light emitting element 42.

Further, in the third embodiment, the surface of the aluminum reflecting mirror 45 is subjected to oxidation treatment to form an alumite insulating layer on the surface. Since alumite is passive, once the oxide layer is formed, no further oxidation proceeds. In addition, the linear reflectance is hardly reduced by this oxidation treatment. Thus, the reflecting mirror 4
5, a pair of leads 43a,
Even if the 43b and the reflecting mirror 45 are in direct contact, a pair of leads 4
There is no short circuit between 3a and 43b. At four places around the reflecting mirror 45, key claws 45a are provided.
The key nails 45a are locked on the upper surface of the glass plate 46 as a radiation part, and are assembled by sandwiching a pair of leads 43a and 43b therebetween.

Here, since the reflecting mirror 45 is made of an aluminum plate, it has a high reflectance in a wavelength region from visible light to ultraviolet light, and does not require plating. In particular, the third embodiment
Since the reflectance of silver is extremely low in the region of ultraviolet rays emitted from the light emitting element 42, the aluminum reflecting mirror 45 can obtain a high ultraviolet reflectance that cannot be obtained by silver plating which is widely performed. In order to form the aluminum reflecting surface, a process such as performing a vapor deposition process on some member is required. However, in the present invention, the aluminum reflecting surface can be embodied by a simple means omitting this process.

Further, since the reflecting mirror 45 is formed in a substantially paraboloid of revolution and the light emitting element 42 is located at the focal point, all the ultraviolet rays emitted from the light emitting element 42 are rotated by the reflecting mirror 45. It is reflected in a direction parallel to the axis of the paraboloid. In the direction, there is a radiating portion 46 made of a glass plate, but since the surface roughness of the radiating portion 46 can be easily made to the surface roughness of an optical level, the radiating portion 46 does not scatter ultraviolet rays. The ultraviolet light reflected by the reflecting mirror 45 is radiated from the radiating section 46 in the same direction.

As a result, almost the entire luminous flux of the ultraviolet light emitted from the light emitting element 42 can be controlled and radiated externally, so that the external radiation efficiency is high and the degree of freedom in designing the light radiation characteristics such as light distribution characteristics is high. And can be. Further, the third embodiment
Since the reflective light emitting diode 41 is not resin-sealed, there is no problem of resin deterioration due to ultraviolet light or short-wavelength light such as visible light. Since the one lead 43a and the reflecting mirror 45 are in direct contact with each other, the heat of the light emitting element 42 is transmitted from the one lead 43a to the reflecting mirror 45 and is radiated from the entire reflecting mirror 45. It becomes an excellent reflection type LED. As a result, a high luminous intensity can be realized, and the reflection type ultraviolet light L
ED can be put to practical use.

Fourth Embodiment Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 7A is a plan view showing the entire configuration of a reflective light emitting diode according to a fourth embodiment of the present invention, and FIG.
FIG. 3 is a longitudinal sectional view showing a section taken along line EE.

As shown in FIG. 7, the reflection type light emitting diode 51 of the fourth embodiment is not a metal, but an alumina (A) which is a ceramic having high thermal conductivity as a reflection mirror.
1 ₂ O ₃ ) 55, a reflection surface 55 a that is a paraboloid of revolution is formed, and aluminum and silicon oxide (SiO ₂ ) are deposited on the reflection surface 55 a. Then, a pair of leads 53a for supplying power to the light emitting element 52 emitting ultraviolet light,
The light emitting element 5 is provided on the lower surface of one of the leads 53a.
2 is mounted, and the other lead 53b and the light emitting element 52 are bonded to each other with a wire 54 for electrical connection. Then, three recesses are formed in the alumina reflecting mirror body 55 to form a pair of leads 53a and 53b. Is fitted. Then, a glass plate 56 as a radiation portion is adhered from above, and the reflection type ultraviolet LED 51 is completed.

The reflection type ultraviolet LED 5 having such a configuration
In No. 1, one lead 53a is in close contact with the alumina reflecting mirror main body 55 having high thermal conductivity at two places.
Since the heat of the light emitting element 52 is transmitted from the one lead 53a to the reflector body 55 made of alumina and is radiated from the entire body 55 of the reflector made of alumina, the reflection type LED has extremely excellent heat dissipation. Further, since the reflection type ultraviolet LED 51 does not need to be resin-sealed, even if the reflection surface 55a is formed by performing aluminum evaporation and silicon oxide evaporation on the reflecting mirror body 55 made of alumina, mass productivity is not hindered.

Here, since the reflecting surface 55a of the reflecting mirror 55 is formed by aluminum evaporation and silicon oxide evaporation, it has a high reflectance in a wavelength region from visible light to ultraviolet light, and particularly the light emission of the fourth embodiment. Since the reflectance of silver is extremely low in the region of the ultraviolet rays emitted from the element 52, a high ultraviolet reflectance that cannot be obtained by the widely used silver plating process can be obtained.

Further, the reflecting surface 55a of the reflecting mirror 55 is formed in a substantially paraboloid of revolution, and the light emitting element 5
2 is located, all the ultraviolet rays emitted from the light emitting element 52 are reflected by the reflecting mirror 55 in a direction parallel to the axis of the paraboloid of revolution. In that direction, there is a radiating portion 56 made of a glass plate. The surface roughness of the radiating portion 56 can be easily adjusted to an optical level, so that the radiating portion 56 does not scatter ultraviolet rays. The ultraviolet light reflected by the reflecting mirror 55 is radiated from the radiating section 56 in the same direction.

As a result, almost the entire luminous flux of the ultraviolet light emitted from the light emitting element 52 can be controlled and externally radiated, so that the external radiation efficiency is high and the degree of freedom in designing the light radiation characteristics such as light distribution characteristics is high. And can be. Further, Embodiment 4
Since the reflective light emitting diode 51 is not resin-sealed, there is no problem of resin deterioration due to short-wavelength light such as ultraviolet light or visible light. As a result, high luminous intensity can be realized, and practical use of the reflection type ultraviolet LED can be achieved. The light emitting element 5
In order to prevent the light emitting element 52 from deteriorating due to humidity due to the fact that No. 2 is not sealed with resin, the inside of the reflective LED 51 may be sealed with dry nitrogen.

In each of the above embodiments, the reflecting surface of the reflecting mirror is formed in a substantially paraboloid of revolution. However, the shape of the reflecting surface of the reflecting mirror is not limited to this, and light emission characteristics such as light distribution characteristics are obtained. Various shapes such as a hemispherical shape and a spheroidal shape can be made according to the requirements of the characteristics.

In each of the above embodiments, an example in which a transparent epoxy resin is used as a light transmitting material for sealing has been described. However, other types of light transmitting materials can be used. In addition, although an example in which a copper alloy plate is subjected to silver plating as a lead was described, various materials such as an iron plate subjected to silver plating and a copper plate subjected to aluminum deposition were also used. Can be used.

The configuration, shape, quantity, material, size, connection relation, and the like of the other parts of the reflection type light emitting diode are not limited to the above embodiments.

[0076]

As described above, the reflection type light emitting diode according to the first aspect of the present invention comprises a light emitting element, a pair of leads for supplying power to the light emitting element, and a light emitting surface of the light emitting element. An opposing concave reflecting mirror, and a radiating portion on the back side of the light emitting element, wherein one of the pair of leads, on which the light emitting element is mounted, and the reflecting mirror are in contact or close proximity to each other. And the one lead and / or
Alternatively, the other lead of the pair of leads and the reflecting mirror are insulated, and the pair of leads and the reflecting mirror are made of a material having high thermal conductivity, and diffuse heat generated by the light emitting element. It has a sufficient heat capacity.

In the reflection type light emitting diode having such a configuration, one of the leads on which the light emitting element is mounted and the reflecting mirror are in contact with or close to each other, so that the heat of the light emitting element is transferred from a material having high thermal conductivity. From one lead, which has a sufficient heat capacity to diffuse the heat generated by the light emitting element, to a reflector made of a material having high thermal conductivity and having a sufficient heat capacity to diffuse the heat generated by the light emitting element Since the heat is transmitted and radiated from the entire reflecting mirror, the heat radiation is extremely good. Since one or both of the one lead and the other lead are insulated from the reflecting mirror, there is no fear that one of the leads and the other lead are short-circuited via the reflecting mirror.

Further, a concave reflecting mirror facing the light emitting surface side of the light emitting element has a high reflectivity, a high external radiation efficiency, and a high degree of freedom in designing light emitting characteristics such as light distribution characteristics. Therefore, a high luminous intensity can be realized.

Further, the use of a reflecting mirror formed of a material having high thermal conductivity makes it resistant to a temperature change. The function as a reflector is not lost. For this reason, a reflow furnace for surface mounting can be used, and it can be used as a surface mounting component without any limitation, so that it is suitable as a reflective LED mounted in a large number. In addition, in the reflection type LED having such a configuration, it is not necessary to take an extra space as a lead lead-out portion, so that it is suitable for miniaturization.

In this way, it has resistance to temperature changes,
It is easy to reduce the size and has excellent heat dissipation.
ED.

According to a second aspect of the present invention, there is provided a reflection type light emitting diode, comprising: a light emitting element;
A pair of leads, a concave reflecting mirror facing the light emitting surface side of the light emitting element, a radiating section on the back side of the light emitting element, and a light transmitting material for sealing; One of the leads on which the light emitting element is mounted and the reflecting mirror are in contact with or close to each other, and the other lead of the one lead and / or the pair of leads;
The reflecting mirror is insulated, the pair of leads and the reflecting mirror are made of a material having high thermal conductivity, have a heat capacity sufficient to diffuse the heat generated by the light emitting element, The light emitting element, a part of the pair of leads, and the reflecting mirror are sealed and molded with the light transmitting material.

In the reflection type light emitting diode having such a configuration, one of the leads on which the light emitting element is mounted and the reflecting mirror are in contact with or disposed close to each other. From one lead, which has a sufficient heat capacity to diffuse the heat generated by the light emitting element, to a reflector made of a material having high thermal conductivity and having a sufficient heat capacity to diffuse the heat generated by the light emitting element Since the heat is transmitted and radiated from the entire reflecting mirror, the heat radiation is extremely good. Since one or both of the one lead and the other lead are insulated from the reflecting mirror, there is no fear that one of the leads and the other lead are short-circuited via the reflecting mirror.

A concave reflecting mirror facing the light emitting surface side of the light emitting element has a high reflectivity, a high external radiation efficiency, and a high degree of freedom in designing light emitting characteristics such as light distribution characteristics. Therefore, a high luminous intensity can be realized. further,
Because the light emitting element is sealed with a light transmitting material,
The light output from the light emitting element is about twice that in the case where the light is directly emitted into the air, and the amount of external radiation can be further increased. Further, since the light emitting element is sealed, deterioration due to moisture is prevented, and a highly reliable reflective LED is obtained.
Furthermore, since the light emitting element, a part of the lead, and the reflecting mirror are sealed and molded with the light transmitting material, the radiating portion emits light by mirror-finishing the inner wall surface of the sealing mold. The surface roughness of the portion is also at the optical level and is formed as an optical surface. As a result, the light reflected by the reflector is radiated from the radiating portion as it is with high external radiation efficiency without scattering at the radiating portion interface.

Further, the final step is a step of merely setting the members in a mold and sealing the resin, and can be easily produced by using an existing production apparatus, and mass production of the reflective LED can be achieved. . Furthermore, by using a reflector formed of a material having high thermal conductivity, the mirror is resistant to temperature changes. There is no loss of functionality. For this reason, a reflow furnace for surface mounting can be used, and it can be used as a surface mounting component without any restrictions.
It becomes suitable as. Further, the reflection type L having such a configuration is used.
The ED does not require an extra space as a lead lead-out portion, and thus is suitable for miniaturization.

In this way, it has resistance to temperature changes,
It is easy to reduce the size, the external radiation efficiency is high, the mass productivity is excellent, and the reflection type LED is excellent in heat dissipation.

According to a third aspect of the present invention, in the reflective light emitting diode according to the first or second aspect, one of the pair of leads is provided with the light emitting element mounted on a peripheral portion of the reflecting mirror. A heat transfer portion for transmitting heat from the lead is formed.

As described above, by forming the heat transfer portion on the peripheral portion of the reflecting mirror, in addition to the effect described in claim 1 or 2, the contact area with one lead on which the light emitting element is mounted is provided. Alternatively, the proximity area is increased, and the heat of the light emitting element can be better transmitted to the reflector via one of the leads, so that the reflection type LED has more excellent heat dissipation.

Further, the use of a reflecting mirror made of a material having high thermal conductivity is resistant to temperature changes, and the reflection due to the occurrence of wrinkles due to temperature changes as in a reflecting mirror or the like on which metal is deposited on a resin surface. It does not lose its function as a mirror. For this reason, it is possible to support a reflow furnace for surface mounting, and it can be used as a surface mounting component without any limitation, so that it is suitable as an LED to be mounted in a large amount. In addition, in the reflection type LED having such a configuration, it is not necessary to take an extra space as a lead lead-out portion, so that it is suitable for miniaturization.

In this way, it has resistance to temperature changes,
It is easy to reduce the size, and the reflection type LED is excellent in heat dissipation.

According to a fourth aspect of the present invention, in the reflective light emitting diode according to any one of the first to third aspects, the pair of leads and the reflecting mirror are formed of a metal plate. It is.

Therefore, in addition to the effects described in any one of the first to third aspects, the metal plate has a high thermal conductivity and is excellent in workability, so that the metal plate easily has a concave reflection. A mirror can be formed. Then, by transmitting the heat of the light emitting element from the one lead made of the metal plate to the reflecting mirror, heat can be radiated from the entire reflecting mirror, and a reflection type LED having extremely excellent heat dissipation can be obtained.

Further, the use of the reflecting mirror formed of a metal plate makes it resistant to temperature changes, and functions as a reflecting mirror due to the occurrence of wrinkles due to temperature changes as in a reflecting mirror or the like in which metal is deposited on the resin surface. Never lose.
For this reason, a reflow furnace for surface mounting can be used, and it can be used as a surface mounting component without any limitation, so that it is suitable as a reflective LED mounted in a large number. In addition, in the reflection type LED having such a configuration, it is not necessary to take an extra space as a lead lead-out portion, so that it is suitable for miniaturization.

Thus, it has resistance to temperature changes,
It is easy to reduce the size and has excellent heat dissipation.
ED.

According to a fifth aspect of the present invention, in the reflective light emitting diode according to any one of the first to fourth aspects, the reflecting mirror is formed of an aluminum plate.

Therefore, in addition to the effects described in any one of the first to fourth aspects, since the aluminum plate is a material which can be easily pressed, it can be easily formed into a reflecting mirror by the pressing. it can. Further, since an aluminum plate having an extremely high linear reflectance can be easily obtained, a reflecting mirror having a high reflectance can be easily produced. Since the heat conductivity is high, the heat of the light emitting element is transmitted from one of the leads to the aluminum-made reflecting mirror, so that heat can be radiated from the entire reflecting mirror. Aluminum has a high reflectance in the wavelength region from visible light to ultraviolet light, and does not require plating when used as a reflecting mirror. In particular, when an ultraviolet light emitting element is used as the light emitting element, since the reflectance of silver is extremely low in the ultraviolet region, aluminum reflecting mirrors have high ultraviolet reflection which cannot be obtained by the widely used silver plating process. Rate can be obtained.

The use of a reflecting mirror formed of an aluminum plate makes it resistant to a temperature change, and functions as a reflecting mirror due to the occurrence of wrinkles due to the temperature change as in a reflecting mirror or the like in which metal is deposited on a resin surface. Never lose. For this reason, a reflow furnace for surface mounting can be used, and it can be used as a surface mounting component without any limitation, so that it is suitable as a reflective LED mounted in a large number. In addition, in the reflection type LED having such a configuration, it is not necessary to take an extra space as a lead lead-out portion, so that it is suitable for miniaturization.

Thus, it has resistance to temperature changes,
It is easy to reduce the size, has a high reflectance, can be applied to an ultraviolet light emitting element, and is a reflective LED excellent in heat dissipation.

According to a sixth aspect of the present invention, in the reflective light emitting diode according to the fourth or fifth aspect, the reflecting mirror has a surface subjected to a light-transmitting insulating treatment.

That is, in the reflection type LED of the present invention, the reflection mirror is obtained by performing a light-transmissive insulating treatment (oxidation treatment) on the surface of a metal plate. By forming the translucent insulating metal oxide on the surface in this way, in addition to the effect of claim 4 or claim 5, the surface of the reflecting mirror is insulated without lowering the reflectance of the reflecting mirror. When both the one lead and the other lead are brought into contact with the reflecting mirror, the one lead and the other lead do not short-circuit. Thereby, the reflection type LE using the metal reflection mirror is provided.
Manufacturing of D becomes easy. Further, since one of the leads can be brought into contact with the reflecting mirror, the heat transfer property is improved, and the heat dissipation property is further improved.

The use of a reflecting mirror formed of a metal plate makes it resistant to temperature changes, and functions as a reflecting mirror due to the occurrence of wrinkles due to temperature changes as in a reflecting mirror or the like in which metal is deposited on a resin surface. Never lose.
For this reason, a reflow furnace for surface mounting can be used, and it can be used as a surface mounting component without any limitation, so that it is suitable as a reflective LED mounted in a large number. In addition, in the reflection type LED having such a configuration, it is not necessary to take an extra space as a lead lead-out portion, so that it is suitable for miniaturization.

Thus, it has resistance to temperature changes,
It is easy to reduce the size, and the reflection type LED is excellent in heat dissipation.

[Brief description of the drawings]

FIG. 1A is a plan view showing an entire configuration of a reflective light emitting diode according to a first embodiment of the present invention, and FIG.
FIG. 2 is a longitudinal sectional view showing a section taken along line AA.

FIG. 2A is a plan view showing the entire configuration of a reflective light emitting diode according to a second embodiment of the present invention, and FIG.
FIG. 3 is a longitudinal sectional view showing a section taken along line BB.

FIG. 3 is a vertical cross-sectional view showing a cross section taken along line CC of FIG. 2A of the reflective light emitting diode according to the second embodiment of the present invention.

FIG. 4 is a longitudinal sectional view showing a modification of the reflective light emitting diode according to the second embodiment of the present invention.

FIG. 5 is a longitudinal sectional view showing another modification of the reflective light emitting diode according to the second embodiment of the present invention.

FIG. 6A is a plan view showing the entire configuration of a reflective light emitting diode according to a third embodiment of the present invention, and FIG.
FIG. 3 is a longitudinal sectional view showing a section taken along line DD.

FIG. 7A is a plan view showing the entire configuration of a reflective light-emitting diode according to a fourth embodiment of the present invention, and FIG.
FIG. 3 is a longitudinal sectional view showing a section taken along line EE.

FIG. 8 is a longitudinal sectional view showing the entire configuration of a conventional reflective light emitting diode.

[Explanation of symbols]

1, 11, 21, 31, 41, 51 Reflective light emitting diode 2, 12, 22, 32, 42, 52 Light emitting element 3a, 13a, 23a, 33a, 43a, 53a One lead 3b, 13b, 23b, 33b, 43b, 53b The other lead 5, 15, 25, 35, 45, 55 Reflecting mirror 5a, 15a, 25a, 35a Heat transfer portion 6, 16, 26, 36 Light transmitting material 7, 17, 27, 37, 46, 56 radiating section

Claims (6)

[Claims] 1. A light emitting device, a pair of leads for supplying power to the light emitting device, a concave reflecting mirror facing a light emitting surface side of the light emitting device, and a radiating portion on a back side of the light emitting device. One of the pair of leads, on which the light emitting element is mounted, and the reflecting mirror are in contact with or close to each other, and the other lead of the one lead and / or the pair of leads is provided. And the reflector is insulated, the pair of leads and the reflector are made of a material having high thermal conductivity,
A reflection type light emitting diode having a heat capacity sufficient to diffuse heat generated by the light emitting element. 2. A light-emitting device, a pair of leads for supplying power to the light-emitting device, a concave reflecting mirror facing a light-emitting surface of the light-emitting device, and a radiating portion on a back side of the light-emitting device. A light-transmitting material for sealing; one of the pair of leads, on which the light emitting element is mounted, and the reflecting mirror are in contact with or disposed in close proximity to each other; Alternatively, the other lead of the pair of leads and the reflector are insulated, and the pair of leads and the reflector are made of a material having high thermal conductivity,
The light emitting element has a heat capacity sufficient to diffuse the heat generated by the light emitting element, and the radiating portion includes a light transmitting element that seals the light emitting element, a part of the pair of leads, and the reflecting mirror with the light transmitting material. A reflective light emitting diode, which is stopped and molded. 3. A heat transfer portion for transmitting heat from one of the pair of leads on which the light emitting element is mounted is formed at a peripheral portion of the reflecting mirror. Or a reflective light-emitting diode according to claim 2. 4. The device according to claim 1, wherein the pair of leads and the reflecting mirror are formed of a metal plate.
The reflective light emitting diode according to claim 1. 5. The reflection type light emitting diode according to claim 1, wherein the reflection mirror is formed of an aluminum plate. 6. The reflection mirror according to claim 4, wherein a surface of the reflection mirror is subjected to a translucent insulation treatment.
3. The reflective light emitting diode according to item 1.