JP2002299700A - Led illuminating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED illuminating device which keeps high hermeticity and has satisfactory heat dissipation capability. SOLUTION: This LED illuminating device comprises a substrate, on one surface of which a plurality of light-emitting diodes are arranged, and a resin case having a bottom part for holding the substrate. The substrate is held by the bottom part via a heat-dissipating fastening plate. Protrusions are formed on a face, which is opposite to the face on which the substrate is held, of the heat-dissipating fastening plate so as to increase the contacting area with the bottom part of the resin case.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an LED lighting device,
In particular, it relates to an LED lighting device for a traffic light.

[0002]

2. Description of the Related Art In recent years, light emitting diodes capable of emitting blue light have been developed, and the luminance of the light emitting diodes has been improved, so that signal lights and lighting equipment using the light emitting diodes have been manufactured. Was. FIG. 9 is a cross-sectional view showing the configuration of a conventional LED lighting device used as, for example, a signal light. In this conventional LED lighting device (hereinafter, referred to as a first conventional example), a plurality of light emitting diodes 5 are arranged. The substrate 4 is provided with a metal plate 101 on the bottom of the resin case 103.
And a transparent cover 7 is provided on the front surface of the resin case 103 to be hermetically sealed. In the conventional LED lighting device configured as described above, light output from the light emitting diode 5 is output via the transparent cover 7, and heat generated by the light emitting diode is transmitted to the bottom of the resin cover 103 by the metal plate 101. Then, heat is radiated from the outer surface of the bottom of the resin cover 103.

Further, the following structure has been proposed as a structure with further improved heat radiation characteristics. LED of FIG.
The illumination device is a conventional LED illumination device (hereinafter, referred to as a second conventional example) having improved heat radiation characteristics as compared with the conventional example of FIG. 9, and as shown in FIG. 10, a metal plate 101a.
Not only the bottom of the resin case 103 but also the resin case 1
03 is provided along the entire inner surface. In the thus configured LED lighting device of FIG.
Since heat can be released from the entire outer surface of FIG.
The heat radiation characteristics can be improved as compared with the conventional example. In addition to the configuration shown in FIG. 10, a structure in which the back surface of the metal plate is provided on the bottom of the resin case so as to directly contact the outside air and a heat sink is provided on the surface that contacts the outside air (hereinafter, a structure in which the heat radiation characteristics are improved). A third conventional example) has also been proposed.

[0004]

However, the first conventional LED lighting apparatus shown in FIG. 9 has a problem that it is not suitable for brighter lighting which requires a large current. Further, the LED lighting device of the second conventional example has good heat radiation characteristics, but has a problem that it cannot be lightened due to the large metal plate. Furthermore, the LE of the third prior art example
The D lighting device has a problem that the sealing performance may be deteriorated because it is necessary to attach the heat radiating surface of the metal plate to the resin cover so as to contact the outside air.

Accordingly, an object of the present invention is to provide an LED lighting device which can maintain high hermetic characteristics and has good heat radiation characteristics.

[0006]

In order to achieve the above object, an LED lighting apparatus according to the present invention comprises a substrate having a plurality of light emitting diodes arranged on one surface, and a resin having a bottom for mounting the substrate. An LED having a case, wherein the substrate is attached to the bottom via a heat radiation fixing plate
A lighting device, wherein a convex portion is formed on a surface of the heat radiation fixing plate opposite to a surface on which the substrate is mounted so as to increase a contact area with a bottom portion of the resin case. Since the LED lighting device configured as described above can increase the contact area between the heat radiation fixing plate and the bottom of the resin case, the heat generated by the light emitting diode is effectively applied to the resin case via the heat radiation fixing plate. The heat can be efficiently radiated from the surface of the resin case,
Good heat dissipation characteristics.

Further, in the LED lighting device according to the present invention, in order to transfer heat generated by the light emitting diodes to the heat radiation fixing plate along one surface of the substrate, the light emitting portion of each of the light emitting diodes is removed. Further, it is preferable that the heat radiation cover further includes a heat radiation cover that covers one surface of the substrate, and the heat radiation cover is fixed so as to be in contact with the heat radiation fixing plate around the substrate.

In the LED lighting device according to the present invention, it is preferable that the heat radiation fixing plate and the resin case are integrally formed.

In the LED lighting device according to the present invention, in order to efficiently transmit heat to the resin case, it is preferable that the convex portions are cooling fins formed to be long in one direction and formed in parallel with each other.

[0010] In the LED lighting device according to the present invention, in order to more effectively release heat from the surface of the resin case, irregularities are formed on the bottom of the resin case corresponding to the projections of the heat radiation fixing plate. More preferably, it is performed.

[0011]

Embodiments of the present invention will be described below. FIG. 1 shows an LED lighting device according to the present invention.
As shown in FIG. 5, a substrate 4 on which a plurality of light emitting diodes 5 are arranged is provided on the bottom of a resin case 3 via a heat radiation fixing plate 1, and a translucent cover 7 is attached to the front surface of the resin case 3. An LED lighting device used for a signal light, which has the following features.

(1) In the LED lighting apparatus of the present embodiment, the heat radiation fixing plate 1 is made of, for example, metal, a plurality of heat radiation fins 1a are formed on the lower surface in parallel with each other, and the fins are formed on the bottom of the resin case 3. 1a is provided so as to be embedded in the resin. In addition, the upper surface of the heat radiation fixing plate 1 is provided so that the lower surface of the substrate 4 is in contact with the upper surface. (2) A heat radiation cover 2 made of, for example, a metal is provided so as to cover the upper surface of the substrate 4 except for the light emitting portion of the light emitting diode 5, and the heat radiation cover 2 is provided around the substrate 4 with the heat radiation fixing plate 1. It is fixed to make surface contact. The heat radiating cover 2 transfers heat generated by the light emitting diode 5 to the heat radiating fixing plate 1.
Has the function of transmitting light to the light emitting die 5
Heat generated in the first path through the heat radiation cover 2;
The heat radiation fixing plate 1 is formed by two paths of the second path through the substrate 4.
, The heat generated by the light emitting diode 5 can be transmitted to the heat radiation fixing plate 1 more effectively. still,
In this specification, the upper side when referring to the upper surface or the lower surface is L
A surface located on the light emitting side (front) of the ED lighting device.

Referring to FIG. 4, the LE of the present embodiment will be described.
The D lighting device will be described in detail. FIG. 4 shows an example in which a light emitting diode 50 of a surface mount type is used. In the LED lighting device of the present embodiment, the heat radiation fixing plate 1 having the fin 1 a formed on the lower surface is fixed to the bottom of the resin case 3 by integral molding. Here, as shown in FIG. 3, the fins 1 a have a fin shape that is sufficiently long in one direction, and are formed on the lower surface of the heat radiation fixing plate 1 in parallel with each other.
In the present embodiment, the heat radiation fixing plate 1 is
a is integrally molded with the resin for molding the resin case so that the a is embedded in the bottom of the resin case 3 and covers the entire lower surface of the heat radiation fixing plate 1.

The substrate 4 on which the light emitting diodes 50 are arranged in a predetermined arrangement on the upper surface is fixed so that the lower surface of the substrate 4 is in contact with the upper surface of the heat radiation fixing plate 1. Further, on the upper surface of the substrate 4, an insulating sheet 6 having a through opening 6 a corresponding to each light emitting diode 50 is provided so as to cover the upper surface of the substrate 4. Then, on the insulating sheet 6, the heat radiating cover 2 in which the through opening 11 a is formed corresponding to the light emitting diode 50 is provided so as to cover the substrate 4 via the insulating sheet 6. Here, when the heat radiating cover 2 covers the substrate 4, the heat radiating cover 2 is bent along the side surface of the substrate 4 so as to make surface contact with the heat radiating fixing plate 1 around the substrate 4, and the heat is radiated at the bent brim portion. It is fixed to the fixing plate 1.

The LE of the embodiment configured as described above
In the D lighting device, as shown by the arrows in the cross-sectional view of FIG. 5, the heat generated by each light emitting diode 50 is transmitted to the heat radiation fixing plate 1 mainly in the thickness direction of the substrate 4 (first path). ) At the same time, separately from the first path, the heat generated by each light emitting diode 50 is transmitted laterally through the heat dissipation cover 2, and from the brim portion which is in surface contact with the heat dissipation fixing plate 1 around the substrate 4. The heat is transmitted to the heat radiation fixing plate 1 (second path). In this manner, the heat transmitted to the heat radiation fixing plate 1 by the first path and the second path is transmitted to the lower surface of the heat radiation fixing plate 1 and the fin 1.
a to the resin at the bottom of the resin case 3 to radiate heat from the surface of the resin.

As described above, in the LED lighting apparatus according to the present embodiment, the heat generated by the light emitting diode 5 can be transmitted to the heat radiation fixing plate 1 by the two paths of the first path and the second path. Therefore, the heat generated by the light emitting die 5 can be effectively transmitted to the heat radiation fixing plate 1. Further, since the plurality of fins 1a are formed on the lower surface of the heat radiation fixing plate 1, the contact area between the lower surface of the heat radiation fixing plate 1 and the bottom surface of the resin case 3 can be increased, and the heat can be efficiently transmitted to the resin case 3. it can. As described above, the LE of the present embodiment
In the D lighting device, the heat generated by the light emitting diode 50 is efficiently transmitted to the resin case 3 and can be released from the outer surface of the resin case 3, so that the heat radiation characteristics can be improved as compared with the conventional example.

Furthermore, in the LED lighting device of the present embodiment, the heat radiation fixing plate 1 is integrally formed with the resin for molding the resin case so that the fin 1a is embedded in the bottom of the resin case 3, so that the anchoring effect is obtained. The heat radiation fixing plate 1 can be firmly fixed to the bottom surface of the resin case 3. Further, in the LED lighting apparatus of the present embodiment, the board on which the light emitting diode is mounted is fixed by the heat dissipation fixing plate 1 and the heat dissipation cover 2 so that the board can be prevented from being displaced and dropped due to vibration. Vibration resistance can be improved. Thereby, for example, high reliability can be obtained even when used in an application such as a signal lamp that is installed in a place constantly exposed to vibration.

Further, in the LED lighting device of the present embodiment, for example, a metal having a shielding effect is used as the heat radiation fixing plate 1 and the heat radiation cover 2 so that the substrate on which the light emitting diode is mounted includes a power supply circuit. Even in such a case, noise generated by the power supply circuit can be cut off, and malfunction of other electronic devices due to noise of the LED lighting device can be prevented. Thereby, it can be applied to a wide range of applications such as various lighting devices in offices and reading lights for aircraft. Further, in the LED lighting device of the present embodiment, since the resin is molded integrally with the resin for molding the resin case so as to cover the entire lower surface of the heat radiation fixing plate 1, the airtightness can be improved.
Long life is obtained even when used for outdoor applications.

In the example shown in FIG. 4 described above, the LED lighting device constituted by using the surface mount type light emitting diode 50 has been described. However, the same constitution can be obtained by using the light emitting diode 5 having pin leads. The same operation and effect can be obtained. That is, as shown in FIG. 6, in the LED lighting device configured using the light emitting diodes 5, the insulating sheet 6 formed on the upper surface of the substrate 4 in FIG.
, Except that the insulating sheet 60 is provided under the lower surface of the substrate 4. Here, FIG.
It is sectional drawing which expands and shows a part cross section of ED lighting device (it comprised using the light emitting diode 5 which has a pin lead).

Hereinafter, a modified example according to the present invention will be described. Modification 1 FIG. 7 is a partial cross-sectional view of the LED lighting device of Modification 1 according to the present invention. The LED lighting device according to the first modification includes a fin 1 a adjacent to the bottom of the resin case 3.
In this case, the concave portions 3a are formed corresponding to the respective portions, whereby the surface area of the outer surface of the bottom of the resin case 3 can be increased, and heat can be efficiently released from the outer surface. That is, in the first modification, irregularities are formed on the bottom (outer surface) of the resin case 3 so as to correspond to the irregularities of the heat radiation fixing plate 1, and the resin case 3 is a main part for releasing heat to the outside air. Increase the surface area of the bottom outer surface,
The heat release effect is further improved.

Modification 2 FIG. 8 shows a second modification of the present invention.
It is a fragmentary sectional view of the LED lighting device. The LED lighting device of Modification 2 has the same configuration as that of FIG. 1 except that the LED lighting device of FIG. 1 is configured using a heat radiation fixing plate 10 instead of the heat radiation fixing plate 1. In FIG. 8, the resin case has a different shape from that of the resin case of FIG. That is, the heat radiation fixing plate 10 used in the LED lighting device of Modification 2 is provided along the bottom portion and the inner peripheral side surface of the resin case 30, and the fin 10 b is formed on the entire portion in contact with the resin case 30. In the LED lighting device of the second modification configured as described above, the heat generated by the light emitting diode 5 is transferred to the resin case 3 via the heat radiation fixing plate 10.
0 can be transmitted to the bottom surface and the outer peripheral side surface of the resin case 30, and heat can be released from the entire outer surface of the resin case 30. Thereby, heat can be released more efficiently than the LED lighting device of the embodiment.

Modification 3 In the LED lighting device of the embodiment, the insulating sheet 6 or the insulating sheet 60 is used. However, instead of the insulating sheet, grease or the like having excellent insulation and heat conductivity may be used.

As described above, the LED lighting apparatus according to the embodiment and the modified example has the following features. (1) By providing the heat radiating cover 2, the heat generated in each light emitting diode by two heat transfer paths is mainly transmitted to the heat radiating fixed plate 1. (2) Increase the area of contact between the heat radiation fixing plate 1 and the resin case, and (3) Increase the area of the outer surface of the portion of the resin case 3 where heat is transmitted to a large extent (related to the first modification). By adopting such a structure, the heat radiation characteristics of the entire LED lighting device are improved. As described above, the good heat radiation characteristics mainly due to the specific structure in the present invention have been described.
In order to more effectively exhibit good heat radiation characteristics due to these unique structures, it is preferable to apply the following materials to each component.

That is, in the LED lighting device of the present invention, it is preferable to use, for example, a metal having good heat conductivity such as aluminum or copper or a ceramic having good heat conductivity as the heat radiation fixing plate 1. It can be produced by casting, forging or cutting. When ceramic is used, it can be manufactured by firing after molding into a predetermined shape. Moreover, in order to improve the heat radiation amount of the heat radiation fixing plate 1, the surface may be painted using black alumite treatment or black paint.

The resin for the resin case 3 is A
It is preferable to use a resin having relatively high thermal conductivity such as BS resin or polycarbonate, and to further improve thermal conductivity, add alumina, aluminum nitride (AlN) or beryllium oxide (BeO) to the resin. More preferably,

[0026]

As described above in detail, in the LED lighting device according to the present invention, the substrate in which the plurality of light emitting diodes are arranged on one surface increases the contact area with the bottom of the resin case. Is attached via a heat-dissipating fixing plate having a convex portion formed thereon, so that the heat generated by the light-emitting diode is effectively transmitted to the resin case through the heat-dissipating fixing plate and from the surface of the resin case. The heat can be efficiently radiated, and the heat radiation characteristics can be improved. Thereby, according to the LED lighting device of the present invention, since the heat radiation characteristics can be improved without directly exposing the heat radiation fixing plate to the outside air, a high sealing characteristic can be maintained, and the LED lighting device having good heat radiation characteristics can be provided. Can be provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of an LED lighting device (an example using a light emitting diode having a pin lead) according to an embodiment of the present invention.

FIG. 2 is a plan view of the bottom surface of the resin case 3 to which the substrate 4 is attached, as viewed from the front in the LED lighting device of FIG.

FIG. 3 is a plan view of a lower surface of the heat radiation fixing plate 1 according to the embodiment.

FIG. 4 is an exploded perspective view of the LED lighting device according to the embodiment (an example using a surface-mount type light emitting diode).

FIG. 5 is a cross-sectional view of an LED lighting device (an example using a surface-mount type light-emitting diode) according to an embodiment.

FIG. 6 is a partial cross-sectional view of the LED lighting device of FIG. 1;

FIG. 7 is a partial cross-sectional view of an LED lighting device according to a first modification of the present invention.

FIG. 8 is a partial cross-sectional view of an LED lighting device of Modification 2 according to the present invention.

FIG. 9 is a cross-sectional view of a first conventional LED lighting device.

FIG. 10 is a cross-sectional view of a second conventional LED lighting device.

[Explanation of symbols]

 1, 10: heat radiation fixing plate, 1a, 10b: heat radiation fin, 2: heat radiation cover, 3, 30: resin case, 4: substrate, 5, 50: light emitting diode, 6, 60: insulating sheet, 7: transparent Light cover.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3K013 AA07 BA01 CA05 CA07 CA16 3K014 LA01 LB04 3K080 AA12 AA14 AB00 BA07 BB01 BD01 CC06 5F041 AA33 DB01 DC07 DC22 DC71 FF11 FF16

Claims (5)

[Claims] 1. A semiconductor device comprising: a substrate on which a plurality of light emitting diodes are arranged on one surface; and a resin case having a bottom for mounting the substrate, wherein the substrate is attached to the bottom via a heat radiation fixing plate. An LED lighting device, wherein a protrusion is formed on a surface of the heat radiation fixing plate opposite to a surface on which the substrate is mounted so as to increase a contact area with a bottom of the resin case. Lighting equipment. 2. A heat-dissipating cover covering one surface of the substrate except for a light-emitting portion of each of the light-emitting diodes, and the heat-dissipating cover is in surface contact with the heat-dissipating fixing plate around the substrate. 2. The LE according to claim 1, wherein the LE is fixed as follows.
D lighting device. 3. The LED lighting device according to claim 1, wherein the heat radiation fixing plate and the resin case are integrally formed. 4. The LED lighting device according to claim 1, wherein the projections are cooling fins formed to be long in one direction and formed in parallel with each other. 5. The LED lighting device according to claim 1, wherein the bottom of the resin case is formed with irregularities corresponding to the projections of the heat radiation fixing plate.