JP2012129097A - Led lighting lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED lighting lamp with temperature at a light-emitting part low, brightness of LED illumination high, and, especially, with high thermal emittance.SOLUTION: The LED lighting lamp is provided with a resin-made LED lighting case 1 and a thermally conductive LED lighting substrate mounting base plate 2 with an LED lighting substrate 4 mounted. A contact area ratio which is an area ratio of a part of an upper surface of the resin-made LED lighting case 1 in contact with the LED lighting substrate mounting base plate 2 to an area of the upper surface of the lighting case 1 is to be 25% or more. A metal material is mounted along a heat dissipation surface 8 of the resin-made LED lighting case 1 to connect to the LED lighting substrate mounting base plate 2.

Description

The present invention relates to an LED lamp, and more particularly to an LED lamp having a high thermal emissivity.

2. Description of the Related Art Conventionally, LED (light emitting diode) elements are used as light sources such as indicator lamps because they are small in size, have a long life, and are excellent in power saving.
In recent years, LED elements with higher luminance have been manufactured at a relatively low cost, and their use as light sources to replace fluorescent lamps and incandescent bulbs has been studied.
When applying to such a light source, in order to obtain a large illuminance, a plurality of LED elements are arranged on a surface mount type LED package, that is, a base substrate made of metal such as aluminum (LED mounting substrate), for example, A method of arranging a reflector that reflects light in a predetermined direction around each LED element is frequently used.
However, since LED elements generate heat during light emission, in such a type of LED lighting device, a temperature increase during light emission of the LED elements leads to a decrease in luminance, a shortened life of the LED elements, and the like.

On the other hand, metal materials are used for current heat dissipation members for LED lighting housings. However, due to processing into fin shapes, the problem is that productivity is low and costs are high. There is an increasing demand for replacement of materials from injection molded articles using thermoplastic resins with excellent productivity.
However, a thermoplastic resin is inferior in heat dissipation due to its extremely low thermal conductivity with respect to a metal material, and therefore cannot be used unless it is imparted with thermal conductivity for use in a heat dissipation member for an LED lighting housing.

As a method for imparting thermal conductivity to a thermoplastic resin, a method of blending a high thermal conductivity filler has been proposed (see Patent Documents 1 to 6).
However, in addition to heat dissipation, the LED lighting housing must have flame retardancy, insulation, and good moldability, and there is no thermoplastic resin that can satisfy all of these requirements. Conversion has not been fully achieved yet.
Recently, weight reduction by resinization and a beautiful white appearance are also required.

In contrast, LED lighting and vehicle headlamp units are provided that use a synthetic resin housing to reduce weight and cost, and to provide a sufficient heat dissipation effect. (See Patent Document 7 and Patent Document 8).
However, the LED illumination lamp includes a synthetic resin casing, a synthetic resin lens frame, a metal ring-shaped heat dissipation member, a substrate mounted on the back surface of the heat dissipation member, and an LED mounted thereon, and a lens. The vehicle headlamp unit includes an LED lamp, a reflector, a heat sink, and an outer case, and each includes a thermally conductive LED lighting board mounting base plate on which the LED lighting board is mounted. LED lighting is not described.

JP 2002-069309 A JP 2004-059638 A JP 2008-033147 A JP 2008-195766 A JP 2008-270709 A JP 2006-117814 A JP 2010-232022 A JP 2008-277237 A

  An object of the present invention is to lower the temperature of the light emitting part of the LED illumination of the resin casing and increase the brightness of the LED illumination.

The present invention employs the following means in order to solve the above problems.
(1) An LED illuminating lamp including a resin LED lighting housing and a heat conductive LED lighting substrate mounting base plate on which the LED lighting substrate is mounted, with respect to the area of the upper surface of the resin LED lighting housing, The LED illumination lamp is characterized in that a contact area ratio, which is a ratio of an area of a portion where the LED illumination board mounting base plate and an upper surface of the resin LED illumination housing are in contact with each other, is 25% or more.
(2) An LED illuminating lamp including a resin LED lighting housing and a thermally conductive LED lighting substrate mounting base plate on which the LED lighting substrate is mounted, wherein the LED is mounted on the upper portion of the resin LED lighting housing. The contact area ratio, which is a ratio of the area of the fitting portion of the LED illumination board mounting base plate to the area of the inner surface of the resin LED lighting housing, is 25 in the horizontal direction. % LED lighting.
(3) The LED illumination lamp according to (1) or (2), wherein a metal material is attached along the heat radiation surface of the resin LED illumination housing and connected to the LED illumination board attachment base plate. is there.
(4) An LED illuminating lamp including a resin LED lighting housing and a heat conductive LED lighting substrate mounting base plate on which the LED lighting substrate is mounted, and along the heat radiation surface of the resin LED lighting housing The LED illumination lamp is characterized in that a metal material is attached and connected to the LED illumination board attachment base plate.
(5) The LED illumination lamp according to (3) or (4), wherein the attachment length of the metal material is 20% or more of the length of the heat radiation surface of the resin LED illumination housing. .
(6) The LED illumination lamp according to any one of (3) to (5), wherein the metal material is attached to an inner surface of the resin-made LED illumination housing in a spiral structure.
(7) The LED lamp according to any one of (3) to (5), wherein the metal material is attached to the inner surface of the resin LED lighting housing in a plurality of parallel strips. It is.

  In the LED illumination lamp of the present invention, the temperature of the light emitting part is low, and the brightness of the LED illumination is high.

It is the figure which showed resin-made LED illumination housing | casings, and is a top view and a front view. It is the figure which showed the heat conductive LED illumination board attachment base board, and is a top view, a front view, and a bottom view. It is the figure which showed the heat dissipation evaluation method using the resin-made LED illumination housing | casing of FIG. 1 and the heat conductive LED illumination board attachment base board of FIG. 2, and is a top view and a front view. It is a front view which shows the contact condition of a heat conductive LED illumination board attachment base plate and resin LED illumination housing. It is a front view which shows the attachment condition of the metal material to the thermal radiation surface of resin-made LED lighting housings.

Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.
Moreover, the part and% in this invention are shown on a mass basis unless otherwise indicated.

  The LED illuminating lamp of the present invention comprises a resin-made LED illumination housing (hereinafter referred to as a resin housing) to which a heat conductive LED illumination board mounting base plate (hereinafter simply referred to as a base plate) is attached.

  The resin casing of the present invention is formed by molding a thermoplastic resin composition such as polyamide resin (for example, nylon-6, nylon-66), polyphthalamide resin, and polycarbonate resin, for example, as shown in FIG. As shown in FIG.

  The thermoplastic resin composition for a resin casing of the present invention (hereinafter simply referred to as a thermoplastic resin composition) preferably has a thermal conductivity of 1.0 W / (m · K) or more, but is not particularly limited. .

  The thermoplastic resin composition preferably has a thermal emissivity of 0.70 or more, and more preferably 0.75 or more, from the viewpoint of heat dissipation.

  The thermoplastic fat composition is preferably flame retardant of UL94 standard V-1 or higher, particularly preferably V-0.

The thermoplastic resin composition is preferably the specific gravity from the viewpoint of weight reduction is 2.50 g / cm ³ or less, 2.20 g / cm ³ or less is more preferable.

  The thermoplastic resin composition can be obtained using a general melt-kneading apparatus. For example, there are screw extruders such as a single screw extruder, a meshing same direction rotating or a meshing different direction rotating twin screw extruder, and a non- or incomplete meshing type twin screw extruder.

  The method of molding the thermoplastic resin composition to obtain a resin casing is not particularly limited, and a known molding method can be used. For example, there are injection molding, extrusion molding, press molding, vacuum molding, blow molding and the like, and injection molding is preferable from the viewpoint of productivity.

In the present invention, a base plate on which an LED illumination substrate is mounted is attached to the upper surface of a resin casing formed by molding a thermoplastic resin composition, and a transparent cover is attached to obtain an LED illumination lamp.
When attaching the base plate, heat radiation grease can be applied to the upper surface of the resin casing.

In the present invention, when the LED illumination board is mounted on the base plate, it is preferable to use a heat conductive spacer therebetween.
The heat conducting spacer to be used can be made of, for example, a silicone resin having a thickness of 1 mm and a heat conductivity of 1 W / (m · K). Specifically, a thermal conductive spacer manufactured by Denki Kagaku Kogyo Co., Ltd. can be used.

The base plate used in the present invention is a metal plate having high thermal conductivity, and an aluminum plate or the like is used because of its availability.
The size of the base plate is not particularly limited. For example, a base plate having a diameter of 51.95 mm, a thickness of 2 mm, and a thermal conductivity of 230 W / (m · K) can be used.

  In the present invention, the contact area ratio, which is the ratio between the total area of the upper surface of the resin casing and the contact area where the base plate contacts the upper surface of the resin casing, is 25% or more. If it is 25% or more, the heat radiation of the LED illumination substrate is sufficient, the temperature of the light emitting portion is lowered, and the brightness of the LED illumination is increased.

Moreover, in this invention, it is preferable from the surface of heat dissipation improvement to fit a base board in the resin housing | casing which notched the upper part.
The notch depth and the edge thickness after the notch are preferably about 2 mm. In order to reduce the thermal resistance, it is also possible to apply heat radiating grease to the resin casing and the base plate.
When the base plate is fitted to the resin casing, the contact area ratio is 25% or more in the horizontal direction.

  Furthermore, in the present invention, it is possible to attach or embed a metal material on the heat radiating surface of the resin casing for attachment and further connection to the base plate.

  Here, examples of the metal material include aluminum foil, gold foil, silver foil, and copper foil, and are not particularly limited. For example, in the case of an aluminum foil having a thermal conductivity of 230 W / (m · K). The thickness is preferably 50 to 200 μm.

The method for attaching the metal material is not particularly limited as long as the heat dissipation of the resin casing is sufficient, and a method of joining the base plate from the upper surface of the resin casing to the inner surface of the casing is effective.
In addition, it is possible to attach a metal material in a spiral structure or a belt shape.

  Here, when the ratio b / a of the length b of the attached metal material to the length a of the heat radiating surface of the resin casing is defined as the metal material attachment length rate, the larger the metal material attachment length rate, the larger the LED. The temperature can be lowered, and the metal material attachment length ratio is preferably 20% or more.

  Hereinafter, although detailed content is demonstrated using an experiment example, this invention is not limited to the following experiment examples.

Experimental example 1
A thermoplastic resin composition comprising a polyamide resin, a metal hydroxide flame retardant, and an additive was used, and an evaluation resin casing shown in FIG. 1 was produced by an injection molding machine.
The thermoplastic resin composition had a thermal conductivity of 1 W / m · K and a thermal emissivity of 0.8.
On the upper part of the base plate, as shown in FIG. 3, a thermal conductive spacer (FSL-100B) manufactured by Denki Kagaku Kogyo Co., Ltd., and an LED lighting board (LDA8D-A1 / D, number of LEDs: 6) manufactured by Panasonic Electric Works Co., Ltd. A transparent cover made of polycarbonate resin was attached to the top.
A power of 7.6 W was loaded, and thermocouples were attached to the central part (hereinafter referred to as the heat generating part of the LED lighting board) and the resin casing on the LED lighting board. The LED lighting was continuously irradiated for 2 hours from the temperature of the heat generating part of the LED lighting substrate and the resin casing part (room temperature 23 ° C.), the temperature of the heat generating part of the LED lighting board was measured, and the heat dissipation was evaluated. The results are shown in Table 1.
As shown in FIG. 4 under the same power condition, an experiment was similarly performed when the contact area between the base plate in close contact with the heat generating portion of the LED lighting substrate and the resin casing was increased. The results are also shown in Table 1.

<Materials used>
Polyamide resin: Nylon 6, manufactured by Ube Industries, trade name “1013B”, density 1.14 g / cm ³
Metal hydroxide flame retardant: Magnesium hydroxide, manufactured by Kamishima Chemical Co., Ltd., trade name “S-4”, volume average particle size 0.9 μm, density 2.40 g / cm ³
Additive: Polytetrafluoroethylene resin, manufactured by Mitsui DuPont Chemical Co., Ltd., trade name “31-JR”, density 2.10 g / cm ³
Thermal conductive spacer: Silicone resin, diameter 35mm, thickness 1mm, thermal conductivity 1W / (m ・ K)
Base plate: 99% pure aluminum plate, diameter 58mm, thickness 2mm, thermal conductivity 230W / (m · K)

<Measurement and evaluation method>
Thermal conductivity: Measured according to ASTM E 1461 using a thermal conductivity measuring device (LFA447 Nanoflash) manufactured by NETZSCH.
Thermal emissivity: Measured using an emissometer (D and SAERD) manufactured by Kyoto Electronics Industry Co., Ltd. As a test piece for evaluation, a square plate of 90 × 90 × 2 mm thickness produced by an injection molding machine (IS50EPN) manufactured by Toshiba Machine Co., Ltd. was used.
Heat dissipation: A thermocouple was attached to the heat generating part and the resin casing of the LED lighting substrate. The LED lighting was continuously irradiated for 2 hours from the temperature of the heat generating part of the LED lighting board and the resin casing, and the temperature of the heat generating part of the LED lighting board was measured to evaluate the heat dissipation. The laboratory temperature is 23 ° C.

In the structure shown in FIG. 3, the LED temperature after 2 hours of irradiation is about 97 ° C.
As shown in FIG. 4 under similar power conditions, the LED temperature can be lowered to 80 ° C. when the heat generating portion of the LED illumination board has a structure in which the contact area between the base plate and the resin casing is increased. This is due to the effect of expanding the heat flow path to efficiently flow the heat generated by the LED lighting board to the resin case. Table 1 shows the relationship between the contact area ratio between the base plate and the resin case and the LED temperature. The LED area temperature can be lowered as the area ratio increases, and the contact area ratio between the base plate and the resin casing is preferably 25% or more.

Experimental example 2
As shown in FIG. 5, the contact area ratio between the base plate and the resin casing is set to 49%, and a 100 μm-thick aluminum foil having a thermal conductivity of 230 W / (m · K) as a metal material is attached. The experiment was conducted in the same manner as in Experimental Example 1 with the end connected to the base plate. The results are shown in Table 2.

  As is apparent from Table 2, when the aluminum foil is attached to the heat radiating surface of the resin casing, the LED temperature can be lowered to 70 ° C. This is due to the effect that the temperature is more widely dispersed with respect to the heat dissipation surface, and the attachment length ratio of the metal material, which is the ratio b / a of the aluminum foil attachment length b to the length a of the entire heat dissipation surface, is The larger the LED temperature, the lower the LED temperature, and the attachment length ratio is preferably 20% or more.

  The LED illumination using the resin casing of the present invention can be used for, for example, a flashlight, a passenger car lamp, a bulb-type illumination, a spotlight, a nightlight, a side illumination, a street light, a road illumination light, and the like.

DESCRIPTION OF SYMBOLS 1 Resin LED illumination housing 2 LED illumination board attachment base board 3 Thermal conductive spacer 4 LED illumination board 5 LED
6 Transparent cover 7 Thermocouple mounting position (heating part of LED lighting board)
8 Heat dissipation surface

Claims (7)

  An LED illumination lamp including a resin LED illumination housing and a heat conductive LED illumination substrate mounting base plate on which the LED illumination substrate is mounted, and the LED illumination with respect to the area of the upper surface of the resin LED illumination housing An LED illumination lamp characterized in that a contact area ratio, which is a ratio of an area of a portion where a substrate mounting base plate and an upper surface of the resin LED lighting housing are in contact with each other, is 25% or more.   An LED lighting lamp comprising a resin LED lighting housing and a heat conductive LED lighting substrate mounting base plate mounted with the LED lighting substrate, wherein the LED lighting substrate is mounted on top of the resin LED lighting housing The contact area ratio, which is the ratio of the area of the fitting portion of the LED lighting board mounting base plate to the area of the inner surface of the resin LED lighting housing, is 25% or more in the horizontal direction. LED lighting characterized by being.   3. The LED illumination lamp according to claim 1, wherein a metal material is attached along the heat radiation surface of the resin LED illumination housing and connected to the LED illumination board attachment base plate.   An LED illumination lamp including a resin LED illumination housing and a heat conductive LED illumination substrate mounting base plate on which the LED illumination substrate is mounted, and a metal material along a heat radiation surface of the resin LED illumination housing And connecting to the LED illumination board mounting base plate.   The LED illumination lamp according to claim 3 or 4, wherein a mounting length of the metal material is 20% or more of a length of a heat radiation surface of the resin LED lighting casing.   The LED illumination lamp according to any one of claims 3 to 5, wherein the metal material is attached to an inner surface of the resin LED lighting housing in a spiral structure.   The LED illumination lamp according to any one of claims 3 to 5, wherein the metal material is attached to an inner surface of the resin LED lighting housing in a plurality of parallel strips.

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