KR20120128318A - A heat-pipe cooler for ledlight emitting diode - Google Patents

Abstract

The present invention is developed as a vacuum superconducting heat pipe with a working fluid (F) made of copper or special metal to generate heat generated from the PCB of the LED lighting device, attached to the back of the PCB as the LED lighting device operates It absorbs the heat generated quickly and disperses it into heat dissipation fins made of aluminum or copper connected along the outer wall of the heat pipe, thereby significantly improving the performance and life of the LED lighting device. In the conventional cooling method in which a simple radiating fin coupled to a PCB of an LED lighting device is combined with cooling or by using a small cooling fan, the heat sink portion combined with the PCB is replaced with a heat pipe. And a heat absorbing part 11 for quickly absorbing heat generated from the PCB, and having a constant height in communication with the heat pipe of the heat absorbing part 11. The heat absorbed through the heat pipe is transferred to the superconductor, and the heat dissipation fin (12) is distributed to the heat dissipation fin, which dissipates the heat dissipation unit (13). High performance LED lighting equipment that overcomes the limitations of the performance of LED lighting equipment that has put limitations can be realized, and energy saving and life improvement of LED lighting equipment can be realized by combining the characteristics of non-powered and semi-permanent heat pipe. It has opened a new horizon in appliance cooling.

Description

LED Lighting Cooling Heat Pipes {A HEAT-PIPE COOLER FOR LED (LIGHT EMITTING DIODE)}

The present invention replaces the heat sink of the heat absorbing portion with a superconducting heat pipe on the rear surface of the PCB, which is the source of heat generation according to the operation of the LED lighting device, and has a diameter of about 25 mm in communication with the heat pipe, which is the heat absorbing portion 11 replacing the heat sink. The heat pipe extends to a heat pipe that transfers and dissipates heat within a standard height limit of the LED lighting device, and constitutes a transfer / dispersion unit 12 and surrounds the outer wall of the heat pipe, which is the transfer / dispersion unit 12. By combining the heat radiating fins, which are the heat radiating elements, the heat generated by the operation of the LED lighting device is quickly absorbed, transferred, and distributed by using a heat pipe to dissipate heat, thereby maintaining a constant temperature of the PCB. The present invention relates to a heat pipe (1) for cooling an LED lighting device that enables a semi-permanent non-powered, high power, high performance LED lighting device that could not be implemented.

LED is expected to be a potential candidate for the next generation lighting source, but its performance is confused with expected target value and actual use effect, and there is a difference between the necessary characteristics in the field of display and the required characteristics for general lighting applications. It is not understood that it is not understood.

In particular, while the need to replace the existing lighting device, the technology to manufacture high-power LED lighting fixtures have already been used, but it does not solve the problem of heat dissipation due to the increase in the performance of the LED lighting fixtures, as a perfect replacement device for now It is not recognized.

Therefore, in order to solve these problems, heat dissipation technology is most necessary to properly understand the performance of LED lighting products and to have the performance as a perfect replacement device.

The role of the light source for illumination is to light the object and recognize the reflected light with the human eye. At this time, the state recognized by the eyes should be close to the state reflected by natural light unless it is a special case.

Therefore, the light distribution from the light source should be diffusely less directional like natural light, and the light color needs to include all the color components of visible light from red to violet in order to reproduce the color of the object well. At this time, the average color rendering index should be 85 or more in order to sufficiently reproduce the color.

In the efficiency evaluation, it is equivalent to the straight fluorescent lamp (80 lm / W or more), and in general lighting applications, the time that the luminous flux reaches 70% of the initial state when the rated input (current) is turned on is equivalent to the straight fluorescent lamp. It must be more than that.

The light emission of an LED is a band energy specified by a material. Inherently, it is colored band light of red, green, blue, etc. centering on a specific wavelength. The light emitting devices including three colors of blue, green, and red are collected into one package to emit white light with the mixed color. In addition, blue light is used to excite and emit a yellow light as a part thereof to emit white light with blue light and yellow light. There is a method of exciting white phosphor by excitation of visible light through ultraviolet radiation.

 The voltage and current characteristics of LEDs are electrically equivalent to diodes used for rectification. The forward voltage is about 3 ~ 3.5V, and this figure is closely related to the emission wavelength, but the forward voltage does not change even in high power LED regardless of LED size or power. This is a significant difference from the conventional light source.

On the other hand, when a current above forward voltage is applied, the current flows almost indefinitely, which causes the LED to break. This is similar to a discharge lamp such as a fluorescent lamp or a high intensity discharge (HID) lamp, and a ballast such as a current limiting device is required to stably light. Therefore, to use 100V power supply, it is necessary to attach a current limiting device by connecting several LEDs of 20 to 30 in series. In general, the shell type LED has a current of 20mA and the power LED has 0.3 ~ 1.5A.

White LEDs hardly contain red radiation (heat rays) which are heat rays in the light emitting component. Therefore, when used as a spot light (heat) is less heat to the irradiation surface, the LED itself is also less heat loss, it is easy to be mistaken that the heat generation is inadequate, but in reality, heat dissipation is a big problem in the LED lighting device.

The energy efficiency of the white LED by commercially available blue and yellow light emitters, that is, the ratio of the light output to the electrical input, is 20-25% for the shell type of 50-60 lm / W and 80-90 for the luminous efficiency. Even for lm / W power LEDs, this is 25-30%. Therefore, 70% or more of energy other than luminescence finally becomes almost heated. As a result, the luminous efficiency and lifespan of LEDs, which are semiconductors, are lowered due to temperature rise, so the heat dissipation method becomes a practical problem.

Therefore, in a module in which a large number of LEDs are arranged closely, a high temperature may be required, and a forced air cooling device such as a heat radiating fin is required. On the other hand, there is a design problem in the lighting device, and as the high power of the LED device is advanced in the future, the reduction of heat generation and the improvement of the heat dissipation method due to the improvement of efficiency become a big problem.

The lifetime of the LED for lighting is defined as the lighting time until the luminous flux reaches 70% of the initial value as described above, and the value is estimated to be tens of thousands of hours, but there is no official test data. Since the factor that determines the life of semiconductors such as LEDs is considered to be temperature, it is possible to predict semi-permanent life if the temperature is maintained at room temperature if one thinks only of semiconductors.

However, in the case of white LEDs, factors other than temperature must be considered, so it is difficult to apply the estimate as it is. In the case of the shell type, although it is very old data, it has been published about 7000 hours. In some cases, the power LED has less thermal resistance than the shell type and heat dissipation, which is 10% lower than 10,000 hours. In addition, when considering the lifetime of the lighting device, consideration should be given to deterioration of lighting circuits and reflectors other than the LED of the light source unit.

In the existing LED lighting fixtures, a simple heat sink is attached to the LED PCB or a small cooling fan is installed to generate heat generated by the operation of the LED lighting fixtures. There is a problem in that the heat radiation fins that can be mounted has a limitation that it becomes useless in the LED lighting apparatus over a certain power.

In addition, a small cooling fan can be used in a high power LED lighting device than in the case of the simple heat dissipation fin, but the additional power consumption and the life of the PCB, that is, the semiconductor is semi-permanent, whereas the life of the cooling fan motor is usually about three years. The furnace cooling fan has a problem that the life of the LED lighting device is shortened.

In the case of the heat pipe 1 for cooling the LED lighting apparatus according to the present invention, the heat sink, which is the heat absorbing portion 11 that is in close contact with the rear surface of the LED PCB, is replaced with the heat pipe, and the heat pipe is a heat absorbing portion that replaces the heat sink. Heat pipes having a diameter of 25 mm in and out of communication with heat pipes for transferring and dissipating heat within the height limits of the standard specification of the LED lighting device are configured to constitute a heat transfer / dispersion unit 12. By combining the heat dissipation fin which is the heat dissipation unit 13 which surrounds the outer wall of the heat pipe which is the dispersing unit 12, the heat generated by the operation of the LED lighting device is absorbed quickly and transferred to the superconductor to be distributed and transferred to the heat dissipation fin surrounding the outer wall. It will dissipate heat.

Accordingly, by overcoming the limitations of the cooling efficiency of the conventional cooling method using only the heat radiation fin, and semi-permanent and powerless operation, there is an effect of saving energy and further extending the life of the LED lighting device.

By using the heat sink and heat dissipation fins in close contact with the LED PCB of the conventional LED lighting fixture through the present invention, or through the present invention in the energy consumption and cooling efficiency of the cooling method using a cooling fan, shortening the life of the product through the present invention The heat generated from the PCB of the lighting fixture is rapidly absorbed and transferred to a superconductor and distributed to the heat dissipation fins surrounding the outer wall, thereby overcoming the limitation of cooling efficiency in the form of cooling with a conventional simple heat dissipation fin.

In addition, in the case of the heat pipe (1) for cooling the LED lighting device, the energy loss problem that is pointed out as a problem of the cooling method using a conventional cooling fan that requires additional power, and the life of the LED lighting device itself according to the life of the cooling fan. In the problem of shortening the lifespan, it operates without power and has a semi-permanent lifespan, which saves energy and further extends the lifespan of the LED lighting fixture.

1: Perspective view of heat pipe for cooling LED lighting equipment (plane)
2: Perspective view of heat pipe for cooling LED lighting equipment (bottom surface)
Fig. 3: Perspective view of heat pipe for cooling LED lighting fixtures (before joining plane-heat sink fins)
Figure 4: Plan view of heat pipe for cooling LED lighting fixtures
5: Front view of heat pipe for cooling LED lighting fixtures
Figure 6: Bottom view of heat pipe for cooling LED lighting fixtures

The present invention, in order to achieve the above object, by using a heat radiation fin coupled in close contact with the back of the PCB which is the source of heat generated by the operation of the LED lighting mechanism, or in a conventional cooling method using a cooling fan therein, the LED PCB The heat sink, which is in close contact with the rear surface, replaces the heat sink with the heat pipe to serve as the heat absorbing part 11, and heat pipes having a diameter of about 25 mm in and around the heat pipe communicating with the heat pipe, which replaces the heat sink, are illuminated with LED lights. The heat pipe is extended to form a transfer / dispersion unit 12 to transfer and disperse heat within the height limit of the standard mechanism, and the heat radiation fins are formed to surround the outer wall of the heat pipe of the transfer / dispersion unit 12. It provides a heat pipe (1) for cooling the LED lighting fixture consisting of a heat dissipation unit (13) for dissipating heat transferred to the superconductivity through the heat pipe.

The heat pipes of the heat absorbing part 11 and the conveying / dispersing part 12 are heat pipes in a vacuum state in which a working fluid (F) is incorporated, and for this purpose, no additional welding or the like is required through special processing or a mold. In the case of heat radiation fins, which are heat radiation fins, which are heat radiation fins that surround the transport / dispersion unit 12, the inner heat pipe is processed to have the same inner diameter as the outer diameter of the transport / dispersion unit 12. Tighten by using or by pressing.

In addition, in some cases, the heat absorbing portion 11, the transfer / dispersion portion 12, and the heat dissipation portion 13 may be taken out by one body through a special process, and the product may be manufactured through a heat pipe forming process.

The heat absorbing part 11 and the conveying / dispersing part 12 of the LED lighting device cooling heat pipe 1 are in communication with one heat pipe, and the inside is a vacuum state, the working fluid accommodated therein (F) is characterized in that about 5% of the total volume inside the heat pipe (1) for cooling the LED lighting fixture.

(Example)

When the LED lighting fixture cooling heat pipe (1) produced by the present invention is coupled to the back of the LED PCB of 8W power in close contact with the operation of the temperature measurement of the LED side and the surface can be obtained the following results.

* Test condition: Ambient temperature 22 degrees, 8W power LED

1: Heat pipe for cooling LED lighting equipment
11: endotherm
12: transfer / dispersion unit
13: heat dissipation unit
F: working fluid

Claims (4)

In the heat pipe for cooling LED lighting equipment,
The heat pipe (1) for cooling the LED lighting device is constant in communication with the heat absorbing portion (11) and the heat absorbing portion (11) replacing the heat sink for heat absorption on the rear surface of the PCB, which is the origin of the LED lighting device, with the heat pipe. Heat pipe transfer / dispersion unit 12 for carrying out and dispersing the heat having a height to superconductivity, and a heat dissipation unit 13 for dissipating heat transferred through the superconducting heat pipe in a form surrounding the transfer / dispersion unit 12. -Powered, high-efficiency heat pipe for cooling LED lighting fixtures with phosphor heat dissipation fins.
3. The method of claim 1,
In the configuration of the heat dissipation fin 11 which is a heat absorbing part 11, a transfer / dispersion part 12, and a heat dissipation part 13 surrounding the transfer / dispersion part 12,
Conveying / dispersing part 12 The structure of the heat dissipation fin, which is a heat dissipation part 13 having the same inner diameter as the outer diameter of the heat pipe and having an outer diameter within the standard specification of the LED lighting fixture, has a separate fastening type and a heat absorbing part 11, / The heat dissipation part 12, the heat dissipation part 13 consists of one body heat pipe for cooling LED lighting fixtures that can be configured in two forms that can be commercialized only through the heat pipe process.
3. The method of claim 1,
The heat absorbing part 11 and the conveying / dispersing part 12 communicate with each other in a vacuum state, and a heat pipe having a working fluid F therein.
According to claim 3,
A heat pipe for cooling an LED lighting device, wherein the working fluid (F) incorporated in the heat pipe is about 5% of the total heat pipe volume.

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