WO2012015161A1

WO2012015161A1 - Led lighting apparatus comprising thermoelectric cooling module embedded led module

Info

Publication number: WO2012015161A1
Application number: PCT/KR2011/004102
Authority: WO
Inventors: Sung Cheol Heo
Original assignee: Lg Innotek Co., Ltd.
Priority date: 2010-07-29
Filing date: 2011-06-03
Publication date: 2012-02-02
Also published as: KR20120011572A; KR101822600B1

Abstract

Provided is a light emitting diode (LED) lighting apparatus. The LED lighting apparatus includes a LED module, having first and second substrates disposed to face each other, LED elements arranged at one side of the first substrate, and a thermoelectric cooling module including a plurality of thermoelectric elements disposed between the first and second substrate. Accordingly, generated heat is effective cooled down, and a size of a heat sink is significantly reduced.

Description

LED LIGHTING APPARATUS COMPRISING THERMOELECTRIC COOLING MODULE EMBEDDED LED MODULE

This application claims priority to Korean Patent Application No. 10-2010-0073470 filed on July 29, 2010, the contents of which is hereby incorporated by reference in its entirety into this application.

The present invention relates to a light emitting diode (LED) lighting apparatus including a LED module with a thermoelectric cooling module embedded therein.

A light emitting diode (LED) is an intermetallic compound junction diode that creates an injected minority carrier (electron and hole) using a p-n junction of a semiconductor and converts electric energy to light energy through reunion of electron and hole, thereby emitting light. That is, when a forward voltage is supplied to a predetermined semiconductor, electrons and holes become reunited while moving through a junction between a positive electrode and a negative electrode. Since the reunited electron and hole has energy smaller than that of separated electrons and holes, light is emitted due to energy difference. Such LED has been applied to various applications such as a lighting apparatus or a back light source of a liquid crystal display (LCD) device as well as a typical display device.

Particularly, a LED element has advantages of low driving voltage, high energy efficiency, and long life span. Accordingly, the LED has been receiving attention as a light source of a lighting apparatus that could replace a typical fluorescent light and an incandescent light.

Fig. 1 is a cross-sectional view of a typical LED lighting apparatus. Referring to Fig. 1, a typical LED light apparatus includes a LED module 10 having at least one LED element 12 mounted on a circuit board 11, a heat radiating unit 30 disposed under the LED module 10 for radiating heat generated from the LED element 12, a power source module 50 for supplying power, and an external power connection unit 70 for receiving power from an external device. As shown, the typical LED lighting apparatus adapted an air-cooling system using a heat sink 31. Due to the air-cooling system, cooling efficiency is comparatively low. Further, light-emitting efficiency is dropped because the LED element 12 or a packaging resin might be damaged by temperature increased by heat generated from the LED element 12. As a result, the life span of the LED lighting apparatus becomes shorted.

The present invention provides a LED lighting apparatus has an improved structure that effectively cools down heat generated from a LED element and significantly reduces a size of a typical heat sink by integrally forming a thermoelectric cooling module with a circuit board having LED elements in a LED module.

In accordance with an embodiment of the present invention, a light emitting diode (LED) lighting apparatus includes a LED module, wherein the LED module includes: first and second substrates disposed to face each other; LED elements arranged at one side of the first substrate; and a thermoelectric cooling module including a plurality of thermoelectric elements disposed between the first and second substrate.

The thermoelectric elements may be formed by alternatively arranging N-type and P-type elements.

The thermoelectric elements may be connected in series through electrode patterns, which are formed on the other surface of the first and second substrates. In the thermoelectric element, the first substrate may absorb heat and the second substrate may generate heat when power is supplied from an external power source module. Alternatively, the first substrate may generate heat and the second substrate may absorb heat when power is supplied from an external power source module.

The thermoelectric cooling module may further include diffusion prevention layers formed on both sides of the thermoelectric cooling module. The diffusion prevention layer may be made of one of Pb, Sn, Pt, and Ni.

The thermoelectric cooling module may further include a buffer layer disposed between the diffusion prevention layer and the electrode pattern formed on the other side of the first and second substrates. The buffer layer may be made of one of Ni, Ti, Cr, and Ta.

In the thermoelectric element, a pair of an N-type element and a P-type element may be disposed at each electrode formed on the other side of the first insulation substrate.

The first and second substrates may be formed using one of a silicon substrate, an aluminum substrate, an aluminum nitride (AlN) substrate, an aluminum oxide (AlOx) substrate, a photo sensitive glass (PSG) substrate, a BeO substrate, a PCB substrate, an Al₂O₃ substrate.

The electrode pattern may be formed of one of Cu, Au, Ag, and Al or a stacked structure thereof.

The LED lighting apparatus may further include a heat radiating unit having a heat sink at one side of the second substrate. In the heat radiating unit, a height of the heat sink occupies about 10 to 20 % of an overall height of the heat radiating unit.

The LED light apparatus may further include a power source module for supplying power to the LED element and an external electric connection unit.

According to an exemplary embodiment of the present invention, a thermoelectric cooling module is integrally formed at an insulating substrate having LED elements formed thereon in a LED lighting apparatus. Therefore, generated heat can be effectively cooled down, a heat sink can be significantly reduced in size, and an overall size of a LED lighting apparatus can be reduced.

Fig. 1 is a cross-sectional view of a typical LED lighting apparatus.

Fig. 2 is a cross-sectional view of a LED lighting apparatus including a LED module with a thermoelectric cooling module embedded according to an exemplary embodiment of the present invention.

Fig. 3 is a cross-sectional view of a LED module of Fig. 2.

Fig. 4 is a top view of Fig. 2.

Fig. 5 is a top view of a bottom surface of a first substrate of Fig. 3.

The present invention relates to a light emitting diode (LED) lighting apparatus that maximizes overall cooling efficiency, secures reliability thereof, and minimizes an overall size of a lighting device by integrally forming a circuit board having LED elements with a thermoelectric cooling module configured of P-type and N-type thermoelectric semiconductors.

The LED lighting apparatus includes a LED module, wherein the LED module includes first and second substrates facing each others, LED elements arranged at one side of the first substrate, and a thermoelectric cooling module having a plurality of thermoelectric elements arranged between the first and second substrates.

Exemplary embodiments of the present invention will be described below in more detail with reference to the accompanying drawings. Accordingly, the drawings and description are to be regarded as illustrative in nature and not restrictive, and like reference numerals designate like elements throughout the specification. Although a term “first” or “second” may be used to describe various constituent elements, the constituent elements are not limited thereto. The term “first” or “second” may be used only for identifying one constituent element from the other.

Fig. 2 is a cross-sectional view illustrating a LED lighting apparatus including a LED module with a thermoelectric cooling module embedded therein according to an exemplary embodiment of the present invention.

The LED lighting apparatus according to the present embodiment includes a LED module 100 with at least one LED element 190 mounted thereon, a heat radiating unit 300, a power module 400 for supplying power, and an external power connection unit 500. The LED lighting apparatus according to the present embodiment further includes a cover 600 above the LED module 100 to protect the LED element 190 and the circuit board and to transmit light generated from the LED element 190. Particularly, the thermoelectric cooling module is embedded with the LED module 100. Accordingly, heat generated from the LED element is effectively cooled down, and a size of a heat sink 310 in the heat radiating unit 300 is significantly reduced.

Fig. 3 is an enlarged view of a LED module formed above a heat radiating unit in a LED lighting apparatus of Fig. 2.

As shown, the LED module includes first and

second substrates

110 and 120, LED elements 190 arranged at one side of the first substrate, and a thermoelectric cooling module having a plurality of thermoelectric elements 180 arranged between the first and

second substrates

110 and 120.

The LED module 100 may be disposed on the first substrate 110 having

electrode patterns

130 and 140 formed both sides thereof. At least one LED element 190 is formed on the electrode pattern 130. That is, the electrode 130 with LED elements mounted thereon may be formed at one side of the first substrate 110, and thermoelectric elements 180 may be arranged on the other side of the first substrate 100.

Further, the second substrate 120 is formed at a predetermined position corresponding to the first substrate 110. An electrode pattern 150 is formed on the other side of the second substrate. A plurality of thermoelectric elements 180 are formed between the

electrode patterns

140 and 150 of the first and second substrate.

The plurality of thermoelectric elements 180 are formed by alternatively arranging N-type and P-type thermoelectric semiconductor elements at a predetermined gap. Such N-type and P-type thermoelectric semiconductor elements are electrically connected in series and thermally connected in parallel by being connected through the

electrode patterns

140 and 150 of the upper and

second substrate

110 and 120.

Further,

buffer layers

160 and 161 and

diffusion prevention layers

170 and 171 are sequentially formed between the

electrode patterns

140 and 150 and the thermoelectric elements 180. The

buffer layers

160 and 161 improves adherence between the

electrode patterns

140 and 150 and the thermoelectric element 180, and the

diffusion prevention layers

170 and 171 prevent diffusion.

In this case, the

buffer layers

160 and 161 may be formed of at least one of Ni, Ti, Cr, and Ta.

Further, the

diffusion prevention layers

170 and 171 may be formed of at least one of Pb, Sn, Pt, and Ni.

The first and

second substrates

110 and 120 are a ceramic substrate. Preferably, the first and

second substrates

110 and 120 may be an alumina (Al₂O₃) substrate. However, the present invention is not limited thereto. The first and

second substrates

110 and 120 may be formed on at least one of a silicon substrate, an aluminum substrate, an aluminum nitride (AlN) substrate, an aluminum oxide (AlOx) substrate, a photo sensitive glass (PSG) substrate, an Al₂O₃ substrate, a BeO substrate, and a PCB substrate.

As described above, the LED lighting apparatus according to the present embodiment includes the LED module 100 having the thermoelectric cooling module integrally formed with the circuit board 110 having the LED elements 190.

The thermoelectric cooling module uses Peltier effect that absorbs or generates heat according to current. That is, one end of the thermoelectric cooling module absorbs heat and the other end generates heat according to a direction of current flow.

For example, when power is supplied to the thermoelectric element 180 of the thermoelectric cooling module of Fig. 3, current flows from the N-type thermoelectric semiconductor elements to the P-type thermoelectric semiconductor element and the electrode pattern 150 on the second substrate 120 through the electrode pattern 140 of the first substrate 110. As a result, the first substrate 110 absorbs heat and the second substrate 120 generates heat. Alternatively, the first substrate may generate heat and the second substrate 120 may absorb heat.

The thermoelectric cooling module embedded with the LED module 100 effectively cools down heat generated from the LED elements 190 and transfers the heat to the heat sink 310 of the heat radiating unit 300. Accordingly, about 80 to 90% of the heat sink 310 of the heat radiating unit 300 can be reduced in size. That is, an overall size of a LED lighting apparatus can be reduced. Particularly, the heat sink can be significantly reduced in size to occupy about 10 to 20% of the overall size of the heat radiating unit 300.

Fig. 4 is a top view of the LED lighting apparatus of Fig. 2 which includes the LED elements 190 formed on the electrode pattern 130 of the first substrate 100. Although it is formed in a circular donut shape in Fig. 4, it may be formed in various other shapes such as a square shape.

Fig. 5 is a top view of a bottom surface of a first substrate of Fig. 3. Referring to Fig. 5, a pair of a P-type semiconductor element and an N-type thermoelectric semiconductor element is formed on the electrode pattern 140 formed on the bottom surface of the first substrate. The electrode pattern 150 is formed on the second substrate 120 for serial electric connection. When power is supplied through the electrode pattern 150 of the second substrate 120, the first substrate 110 absorbs heat and the second substrate 120 generates heat, thereby effectively cooling down the generated heat. Further, a size of the heat sink can be significantly reduced.

The foregoing exemplary embodiments and aspects of the invention are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. Also, the description of the exemplary embodiments of the present invention is intended to be illustrative, and not to limit the scope of the claims, and many alternatives, modifications, and variations will be apparent to those skilled in the art.

Claims

A light emitting diode (LED) lighting apparatus comprising:

a LED module,

wherein the LED module includes:

first and second substrates disposed to face each other;

LED elements arranged at one side of the first substrate; and

a thermoelectric cooling module including a plurality of thermoelectric elements disposed between the first and second substrate.
The LED lighting apparatus of claim 1, wherein the thermoelectric elements are formed by alternatively arranging N-type and P-type elements.
The LED lighting apparatus of claim 2, wherein the thermoelectric elements are connected in series through electrode patterns, which are formed on the other surface of the first and second substrates.
The LED lighting apparatus of claim 3, wherein in the thermoelectric element, the first substrate absorbs heat and the second substrate generates heat when power is supplied from an external power source module.
The LED lighting apparatus of claim 3, wherein in the thermoelectric element, the first substrate generates heat and the second substrate absorbs heat when power is supplied from an external power source module.
The LED lighting apparatus of claim 3, wherein the thermoelectric cooling module further includes diffusion prevention layers formed on both sides of the thermoelectric cooling module.
The LED lighting apparatus of claim 6, wherein the diffusion prevention layer is made of one of Pb, Sn, Pt, and Ni.
The LED lighting apparatus of claim 6, wherein the thermoelectric cooling module further includes a buffer layer disposed between the diffusion prevention layer and the electrode pattern formed on the other side of the first and second substrates.
The LED lighting apparatus of claim 8, wherein the buffer layer is made of one of Ni, Ti, Cr, and Ta.
The LED lighting apparatus of claim 9, wherein in the thermoelectric element, a pair of an N-type element and a P-type element is disposed at each electrode formed on the other side of the first insulation substrate.
The LED lighting apparatus of claim 8, wherein the first and second substrates are formed using one of a silicon substrate, an aluminum substrate, an aluminum nitride (AlN) substrate, an aluminum oxide (AlOx) substrate, a photo sensitive glass (PSG) substrate, a BeO substrate, a PCB substrate, an Al₂O₃ substrate.
The LED lighting apparatus of claim 11, wherein the electrode pattern is formed of one of Cu, Au, Ag, and Al or a stacked structure thereof.
The LED lighting apparatus of claim 8, further comprising: a heat radiating unit having a heat sink at one side of the second substrate.
The LED lighting apparatus of claim 8, wherein in the heat radiating unit, a height of the heat sink occupies about 10 to 20 % of an overall height of the heat radiating unit.
The LED light apparatus of claim 13, further comprising: a power source module for supplying power to the LED element and an external electric connection unit.