KR20090103263A - Cooling device in a illuminator using LED by peltier effect - Google Patents

Abstract

PURPOSE: A cooling device for a lighting device with an LED using Peltier effect is provided to maintain the brightness of the LED by maintaining a cooling temperature by controlling a semiconductor through a current. CONSTITUTION: A light emitting unit(113) is comprised of a plurality of light emitting diodes. A main power source(115) supplies the power to the light emitting unit. A high thermal conductive metal board(104) absorbs the heat generated from the light emitting unit. An electrical cooling unit(103) discharges the heat absorbed in the high thermal conductive metal board through the Peltier effect.

Description

Cooling device in a illuminator using LED by peltier effect

The present invention relates to a cooling technology of a light emitting diode luminaire which enables effective cooling by continuously dissipating heat generated from the light emitting diode of the light emitting diode luminaire using the Peltier Effect.

In general, in a lighting device using a plurality of light emitting diodes (LEDs), only a part of electricity (about 20 to 30%) is converted into light energy, and the rest is converted into thermal energy to generate heat.

When the temperature generated by the heat does not affect the brightness of the light emitting diode below a certain temperature (for example, 60 ° C.), when the temperature exceeds the predetermined temperature, the brightness of the light emitting diode is affected and the brightness is sharply reduced. As a result, the efficiency of the light emitting diode is reduced. Therefore, a method of removing high heat, which is a factor that hinders the efficiency of the light emitting diode, has been continuously studied.

Conventionally, the proposed method for removing heat generated from light emitting diodes has been developed in three ways: air-cooled, water-cooled, and high thermal conductivity metal substrates.

The air-cooling type mainly uses a wide heat radiating surface using a natural atmosphere and a forced circulation fan. The water-cooling type is composed of a structure having a wide heat radiating surface while using rain water and cooling oil. The high-heat conductive metal substrate is a metal base (aluminum or copper). And a thin copper plate are composed of a substrate in which a high thermal conductive insulator is integrated.

Forced circulation type air-cooled formula has a disadvantage that the volume is large due to the configuration of a wide heat radiation surface and the circulation fan, natural air-cooled system has a disadvantage that it is difficult to maintain the constant efficiency. Water cooling using rainwater has the disadvantage of freezing in winter and the efficiency is not constant, and water cooling using cooling oil causes inconvenience of checking and replenishing the amount of cooling oil. In addition, the high thermal conductivity metal substrate method has advantages such as small substrate size, increased heat dissipation effect, and free design. However, the strength of the material is low and the heat dissipation efficiency varies depending on the thickness of the metal plate and the shape of the heat dissipation plate. There are disadvantages that are difficult to do.

In conclusion, the cooling device applied to the above three conventional light emitting diode lighting fixtures cannot expect a constant cooling effect and can not expect the convenience of management.

Accordingly, the present invention has been proposed to solve the problems of the static cooling effect generated by the cooling device applied to the conventional light emitting diode lighting device as described above, and the various problems of inconvenient management.

The problem to be solved by the present invention is to provide a cooling device of the light emitting diode luminaire to enable effective cooling by continuously dissipating heat generated from the light emitting diode of the light emitting diode luminaire using the Peltier Effect (Peltier Effect). There is.

Another problem to be solved by the present invention is to maintain an appropriate cooling temperature of the light emitting diode by using a micro current, to maintain the brightness of the light emitting diode and to extend the life of the light emitting diode, while simplifying the structure of the lighting fixtures while promoting environmental friendliness In addition, the present invention provides a cooling device for a light emitting diode lighting device to provide high reliability and convenience of maintenance and management.

"Cooling device of a light emitting diode lighting device" according to the present invention for solving the above problems,

In the lighting fixture to secure the brightness, such as a street light or security light using the light emitting diode,

A light emitting unit comprising a plurality of light emitting diodes;

A main power supply unit for supplying driving power to the light emitting unit;

A high thermal conductivity metal substrate in close contact with the light emitting unit and absorbing heat generated from the light emitting unit by a thermoelectric action;

It characterized in that it comprises an electrical cooling unit for emitting the endotherm of the high thermal conductivity metal substrate through the Peltier effect.

In the above, the electrical cooling unit,

A plurality of semiconductors connected in series;

An auxiliary power supply unit supplying driving power to the semiconductor;

A conductor for dissipating heat transferred by said semiconductor;

It characterized in that it comprises an insulator for insulating function while releasing heat of the conductor.

In addition, the cooling device of the LED lighting device according to the present invention,

An insulator provided on an upper portion of the high thermal conductive metal substrate to limit electrical connection between the light emitting portion and the high thermal conductive metal substrate while transferring heat generated from the light emitting portion;

It is preferable to further include a cushioning material provided between the insulator and the light emitting part to cushion an external impact applied to the insulator.

More preferably, the insulator is implemented in ceramic, and the cushioning material is characterized in that the flame-retardant insulating rubber that can withstand high temperatures.

In addition, the electrical cooling unit,

It is preferable to further include a buffer for cushioning the external shock applied to the electrical cooling unit, the buffer is characterized in that the flame-retardant insulating rubber that can withstand high temperatures.

The auxiliary power supply unit may supply a fine current to the semiconductor to maintain a constant cooling temperature of the light emitting unit.

In addition, the high thermal conductivity metal substrate,

It is a board | substrate which integrated the metal base and the thin copper plate by the high thermal conductive insulator, It is characterized by the above-mentioned.

According to the present invention, it is possible to maintain an appropriate cooling temperature by controlling the semiconductor with a fine current, and thus, there is an advantage of ensuring luminance and useful life of the light emitting diode.

In addition, it is possible to simplify the shape of the lighting fixture to reduce the manufacturing cost, and also has the advantage of providing ease of maintenance by extending the life of the light emitting diode.

In addition, by attaching the flame-retardant insulating rubber to the ceramic has an effect that can prevent the ceramic from being damaged by an external impact.

1 is a cross-sectional view of a cooling device of a light emitting diode lighting device according to the present invention.

2 is a structure diagram of a cooling device of a light emitting diode lighting device according to the present invention;

<Explanation of symbols for the main parts of the drawings>

101... semiconductor

102, 103... conductor

104, 105... Insulator

106... Thin copper plate

107, 108... Flame Retardant Insulation Rubber

109... Auxiliary power

110... Heat sink

113... Light emitting part

115... Main power

Hereinafter, described in detail with reference to the accompanying drawings a preferred embodiment of the present invention. If it is determined that the detailed description of the known function or configuration related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

1 is a cross-sectional view of a cooling device of a light emitting diode lighting device according to the present invention, Figure 2 is a structural diagram of a cooling device of a light emitting diode lighting device according to the present invention, the light emitting unit 113, the main power supply 115, flame-retardant insulating rubber 107, high thermal conductive metal substrates 106, 104, 102, electrical cooling sections 101, 103, 105, flame retardant insulating rubber 108, and auxiliary power supply section 109.

The light emitting unit 113 includes a plurality of light emitting diodes, and the main power supply unit 115 supplies driving power to the light emitting unit 113 through a lead wire.

The light emitting unit 113 is adhered by an adhesive (D / B resin) 112 to an upper predetermined position of the die heat sink 110, the lens 114 on the upper portion of the light emitting unit 113. Is fitted. The lens 114 performs a light diffusing function and a function of protecting the light emitting diode.

The flame retardant insulating rubber 107 is coupled by the heat sink 110 and the soldering 111, and the high thermal conductive metal substrates 106, 104, and 102 are coupled to the lower end of the flame retardant insulating rubber 107. Here, the flame retardant insulating rubber 107 and the high thermal conductive metal substrates 106, 104, and 102 are preferably joined by various bonding methods for bonding the metal substrate and the insulating rubber.

The high thermal conductive metal substrate is a metal substrate in which a metal base 102 such as copper or aluminum and a thin copper plate 106 are integrated with a high thermal conductive insulator 104. The insulator 104 of the high thermal conductivity metal substrate has a heat conductivity of 1.8 to 12 W / m.k, which is min 80 μm, and has a heat dissipation effect equivalent to that of a general ceramic substrate. Since the heat dissipation effect of the substrate itself is high, it is possible to miniaturize the size of the substrate. Due to this advantage, the size of the upper heat sink 110 is also reduced.

The electrical cooling unit functions to release heat through the Peltier effect. A plurality of P-type and N-type semiconductors 101 are connected in series, and a driving power supply is supplied to the semiconductors 101 by an auxiliary power supply unit 109. Supplied. The power supply for driving the semiconductor 101 can be sufficiently driven by a direct current with a direct current. The lower portion of the semiconductor 101 is provided with a conductor 103 for dissipating heat transferred by the semiconductor 101, the conductor 103 is preferably implemented by copper or aluminum. A lower portion of the conductor 103 is provided with an insulator 105 made of a ceramic component that insulates and dissipates heat from the conductor 103.

And the lower portion of the insulator 105 is coupled to the flame-retardant insulating rubber 108, which is a cushioning material for preventing the insulator 105 from being damaged by buffering an external impact. The flame-retardant insulating rubber 108, it is preferable to use a flame-retardant insulating rubber that can withstand even when the surface temperature is 800 ℃ to 1600 ℃.

The present invention configured as described above is used as a cooling device for cooling heat generated in a lighting device equipped with a light emitting diode such as a street light, a security light, an electric sign, an automobile light, and the like.

When the operation principle is described, when the LED driving power is supplied to the light emitting unit 113 by the main power supply unit 115 through the lead wire, each light emitting diode emits light, and thus the light generated by the lens 114 Diffuses to serve as a light.

When a plurality of light emitting diodes emit light, heat is generated, and heat is primarily radiated by the heat sink 110, but when heat is generated that cannot be radiated by the heat sink 110 due to continuous light emission, The heat is transmitted through the flame retardant insulating rubber 107 having excellent thermal conductivity and then radiated through a high thermal conductive metal substrate made of a thin copper plate 106 and an insulator 104 and a metal base 102 such as copper / aluminum.

Since the heat dissipation function of the well-known high thermal conductivity metal substrate is a function already known in the field of a lighting device such as an LED, detailed description thereof will be omitted.

Subsequently, substantial cooling is performed by the electrical cooling unit formed under the high thermal conductive metal substrate, wherein the electrical cooling unit absorbs and radiates heat radiation of the high thermal conductive metal substrate by using the Peltier effect.

In general, the Peltier effect refers to a phenomenon in which two different metals have two contacts, and when a potential difference is applied to both ends of the two metals, heat transfer occurs due to the movement of the potential. While moving free electrons must absorb energy in order to move to a higher Fermi level, heat is continuously absorbed on the side that gives up electrons by absorbing and moving the most readily available heat energy, and continuously on the other side. It is a principle.

The amount of current applied and the amount of heat generated / exothermized are shown in Equation 1 below.

Here, dQ means the amount of heat applied, and the current generated by the change of calories is called dI. The proportional constant π is called the Peltier coefficient or the Control Beck coefficient.

As is well known, in order to implement cooling using the Peltier element, a precondition that two different metals have two contacts is required. However, since it is difficult to expect a large cooling effect with one device, the present invention implements an electric cooling unit in the form of a thermoelectric module (TEM) in which several Peltier devices are coupled in series.

The semiconductor 101 used is based on the junction of a P-type semiconductor and an N-type semiconductor. The semiconductor used here does not use a gallium / arsenic semiconductor, commonly referred to as a semiconductor. In order to achieve the best efficiency due to the characteristics of thermoelectric modules, three conditions must be harmonized. These three have to have a high control Beck coefficient, low electrical resistance, and low thermal conductivity. The reason why the electrical resistance is involved is due to the heat generation of the semiconductor itself. Since the amount of energy lost by heat is proportional to the square of the resistance value, the lower the resistance, the less heat is generated in the device itself, thereby suppressing an increase in the overall temperature due to the heat generated by the device itself. Of course, less power is consumed. The low thermal conductivity is to maintain the temperature difference across the device induced by the potential difference. If the thermal conductivity is high, it is meaningless to make the temperature difference between both ends. The sum of all these properties is called the Merit constant. The merit constant is abbreviated as Z, which is expressed as Equation 2 below.

Peltier devices most commonly used are bismuth fluoride (Bi2Te3) and lead tellurium (PbTe).

Accordingly, in the present invention, the semiconductor 101 is implemented by connecting a plurality of P-type semiconductors and N-type semiconductors in series, and when a current is supplied based on the N-type semiconductor, holes in the P-type semiconductor are separated from the upper high-temperature conductive metal substrate. It is generated at the contact and moves toward the contact of the lower conductor 103. Here, the hole plays a role of carrying heat, and consequently, the upper high thermal conductive metal substrate is continuously cooled, and the lower conductor 103 is continuously heated.

Heat emitted from the conductor 103 is discharged to the outside through the insulator 105 and the flame retardant insulating rubber 108, thereby cooling the light emitting diode.

In addition, it is possible to control the cooling temperature by setting the power source for driving the semiconductor 101 as a microcurrent and adjusting it, and consequently, it is possible to maintain an appropriate cooling temperature by controlling the microcurrent.

The present invention is not limited to the above-described specific preferred embodiments, and various modifications can be made by any person having ordinary skill in the art without departing from the gist of the present invention claimed in the claims. Of course, such changes will fall within the scope of the claims.

Claims (5)

In the cooling device of the luminaire to secure the brightness, such as a street light or security light using a light emitting diode, A light emitting unit comprising a plurality of light emitting diodes; A main power supply unit for supplying driving power to the light emitting unit; A high thermal conductivity metal substrate in close contact with the light emitting unit and absorbing heat generated from the light emitting unit by a thermoelectric action; Cooling device of a light emitting diode lighting device comprising an electrical cooling unit for emitting the endotherm of the high thermal conductivity metal substrate through the Peltier effect. The method of claim 1, An insulator provided on an upper portion of the high thermal conductive metal substrate to limit electrical connection between the light emitting portion and the high thermal conductive metal substrate while transferring heat generated from the light emitting portion; And a buffer material provided between the insulator and the light emitting part to cushion an external shock applied to the insulator. The method of claim 1, wherein the electrical cooling unit, A plurality of semiconductors connected in series; An auxiliary power supply unit supplying a fine current to the semiconductor as a driving power source; A conductor for dissipating heat transferred by said semiconductor; An insulator that insulates and dissipates heat from the conductors; Cooling device of a light emitting diode lighting device, characterized in that it comprises a buffer for cushioning the external impact applied to the insulator. The apparatus of claim 3, wherein the insulator is made of ceramic, and the cushioning material is a flame-retardant insulating rubber that can withstand high temperatures. The method of claim 2, wherein the high thermal conductivity metal substrate, A cooling device for a light emitting diode lighting device, comprising: a substrate in which a metal base and a thin copper plate are integrated with a high thermal conductive insulator.