WO2019184794A1

WO2019184794A1 - High-power led heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer

Info

Publication number: WO2019184794A1
Application number: PCT/CN2019/079086
Authority: WO
Inventors: 莫松平; 林潇晖; 陈颖; 贾莉斯
Original assignee: 广东工业大学
Priority date: 2018-03-27
Filing date: 2019-03-21
Publication date: 2019-10-03
Also published as: CN108417703A

Abstract

A high-power LED heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer, comprising a substrate (2), an LED chip (1), a thermoelectric heat sink (4) and a microchannel heat exchanger (5), the LED chip (1) being mounted on the substrate (2); a hot end of the substrate (2) being connected to a cold end of the thermoelectric heat sink (4), and a hot end of the thermoelectric heat sink (4) being connected to a cold end of the microchannel heat exchanger (5). Said heat dissipation structure can significantly reduce the temperature of the hot end of the thermoelectric heat sink (4), so that the temperature of the LED chip (1) is actively reduced, directly by means of the thermoelectric heat sink (4), said heat dissipation structure has a good effect, and can improve the working performance, reliability and service life of the LED.

Description

High-power LED heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer

Technical field

The invention relates to the technical field of LED heat dissipation, in particular to a high-power LED heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer.

Background technique

At present, LED light on the market mostly uses metal sheets or is heated by the substrate of the system to heat up in the air. The main methods adopted by the prior art include: rationally setting the structure of the heat sink, increasing the heat dissipation area; using the active cooling method to dissipate heat or designing the package structure to have a good luminous flux and effective heat dissipation; It is water-cooled, heat pipe, etc. However, the heat dissipation effects of the above prior art methods are not obvious, and the heat dissipation efficiency is low, so that the LED lamp has a deviation of the emission wavelength due to poor heat dissipation, reduces the luminous flux, and even affects the service life of the LED, and these consequences restrict the LED toward Greater power development. For high-power LED lamps or LED product illuminators, the above-mentioned existing air-cooling or water-cooling usually cannot meet the heat dissipation requirements.

Summary of the invention

In view of the deficiencies of the prior art described above, the present invention provides a high-power LED heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer, which combines microchannel heat exchange with semiconductor thermoelectric refrigeration technology to integrate the package. In the structure of the LED illuminator chip, better active heat dissipation is achieved.

The technical solution adopted by the present invention to solve the technical problem thereof is: a high-power LED heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer, including a substrate, an LED chip, a thermoelectric heat sink and a microchannel heat exchanger, the LED chip mounting On the substrate; the hot end of the substrate is connected to the cold end of the thermoelectric fin, and the hot end of the thermoelectric fin is connected to the cold end of the microchannel heat exchanger.

The outlet and inlet of the microchannel heat exchanger are connected to the inlet and outlet of the fluid heat rejection cycle, respectively.

The fluid heat rejection cycle includes a fluid pump and a fluid heat sink in series with the fluid heat exchanger connected to the outlet and inlet of the microchannel heat exchanger to form a closed fluid heat dissipation cycle.

The working fluid in the fluid heat dissipation cycle is a nanofluid working fluid.

The flat tube of the microchannel heat exchanger is provided with a plurality of fine flow passages having a channel equivalent diameter of 10 to 1000 μm, and an inlet and an outlet are arranged on the flat tube.

A fan for air cooling is disposed outside the fluid heat exchanger.

The upper surface of the substrate is provided with a reflector-shaped groove, the LED chip is mounted at the center of the groove, and the upper surface of the silicon substrate is further mounted with an arc-shaped transparent cover.

The substrate is an aluminum substrate or a silicon substrate.

The hot end of the thermoelectric heat sink is connected with the microchannel heat exchanger by a thermal conductive adhesive to facilitate heat conduction.

The pins of the LED chip are fixed on the aluminum substrate by soldering, and the interface between the heat dissipation end of the LED chip and the thermoelectric heat sink is fixed by a thermal conductive adhesive.

The hot end of the silicon substrate is connected to a plurality of pairs of thermocouples using a reflow soldering process, and the other end of the thermocouple is connected to the cold end of the thermoelectric heat sink by a reflow soldering process.

The invention has the beneficial effects that the hot end temperature of the thermoelectric heat sink can be significantly reduced, so that the LED chip is directly cooled by the thermoelectric heat sink, and the effect is good, and the working performance, reliability and service life of the LED can be improved.

DRAWINGS

1 is a schematic structural view of Embodiment 1 of a high-power LED heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer according to the present invention;

2 is a flow chart of a fluid heat dissipation cycle of a high power LED heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer according to the present invention;

3 is a schematic structural view of a microchannel heat exchanger of a high power LED heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer according to the present invention.

4 is a schematic structural view of Embodiment 2 of a high-power LED heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer according to the present invention;

FIG. 5 is a schematic structural view of a part of an LED light source according to Embodiment 2 of a high-power LED heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer according to the present invention.

detailed description

The invention will be described in detail below with reference to the drawings and specific embodiments. The drawings show the specific construction of the preferred embodiment of the invention. The structural features of each component, and if there is a description of the direction (up, down, left, right, front and back), the structure shown in FIG. 1 is taken as a reference, but the actual use direction of the present invention is not limited. herein.

Example 1

A high-power LED heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer, as shown in FIG. 1, includes a silicon substrate 2, an LED chip 1, a thermoelectric heat sink 4, and a microchannel heat exchanger 5, wherein the LED chip 1 is mounted on The cold end of the silicon substrate 2 forms an LED light source portion. The hot end of the silicon substrate 2 is connected to the cold end of the thermoelectric fin 4, and the hot end of the thermoelectric fin 4 is connected to the cold end of the microchannel heat exchanger 5. The LED chip 1 is connected to the silicon substrate 2 by soldering through a lead. The silicon substrate 2 and the thermoelectric heat sink 4 are an integral package structure, and the heat releasing end of the LED chip 1 directly contacts the thermoelectric heat sink 4 to improve heat dissipation efficiency. The thermoelectric heat sink 4 and the microchannel heat exchanger 4 are fixedly connected by a solid glue. The thermoelectric fin 4 is a semiconductor refrigerating sheet (thermoelectric refrigerating sheet) which has no sliding member and has high reliability and no refrigerant contamination. By using the Peltier effect of the semiconductor material, when the direct current is passed through the galvanic couple of two different semiconductor materials in series, the heat can be absorbed and the heat can be released at both ends of the galvanic couple, and the purpose of cooling can be achieved.

The upper surface of the silicon substrate 2 is provided with a reflective cup-shaped recess, the LED chip 1 is mounted at the center of the recess, and the upper surface of the silicon substrate 2 is further mounted with an arc-shaped transparent cover 9 A phosphor layer is disposed in the transparent cover 9, and the transparent cover 9 seals the groove. The hot end of the silicon substrate 2 is connected to one end of a plurality of pairs of thermocouples 3 by a reflow soldering process, and the other end of the thermocouple 3 is connected to the cold end of the thermoelectric heat sink 4 by a reflow soldering process.

The outlet 50 and the inlet 51 of the microchannel heat exchanger 5 are connected to the inlet and outlet of the fluid heat dissipation cycle, respectively. As shown in FIG. 2, the fluid heat dissipation cycle includes a fluid pump 6 and a fluid radiator 7, which are connected in series with the fluid heat exchanger 7, and are connected to the outlet 50 and the inlet 51 of the microchannel heat exchanger 5. A closed fluid heat dissipation cycle is formed. The working fluid in the fluid heat dissipation cycle is a nanofluid working fluid. The nanofluid working fluid is a suspension formed by mixing 1-100 nm solid particles with a liquid heat exchange medium, which has a larger thermal conductivity and a convective heat transfer coefficient than ordinary working fluids (such as water and ethylene glycol). The heat transfer efficiency of the microchannel heat exchanger 5 is effectively improved. After the nanofluid working fluid derives the heat of the LED chip 1 and the thermoelectric heat sink 4, it is circulated and cooled by liquid cooling or air cooling. The nanofluidic working fluid is preferably a suspension in which Cu nanoparticles having a particle diameter of 10 to 50 nm are dispersed in a heat transfer oil base liquid.

As shown in FIG. 3, the flat tubes of the microchannel heat exchanger 5 are provided with dozens of fine flow passages having a channel equivalent diameter of 10 to 1000 μm, and an inlet 51 and an outlet 50 are provided on the flat tubes. The microchannel heat exchanger 5 uses a nanofluid working fluid (refrigerant). Preferably, the flat tube of the microchannel heat exchanger 5 is provided with dozens of fine flow passages having a channel equivalent diameter of 100 to 800 μm, and the inlet 50 and the outlet 51 are respectively connected to a fluid heat dissipation cycle of the working medium circulation passage. A fan 8 that wind-cools the fluid radiator 7 is disposed outside the fluid radiator 7.

After the nanofluid working fluid derivates the heat of the LED and the thermoelectric heat-dissipating substrate, and then performs the circulating cooling by the liquid cooling or the air cooling method, the present invention can significantly reduce the package thermal resistance of the LED and the thermoelectric heat sink compared with the prior art. The LED is directly cooled by the heat and heat dissipation, and the effect is good, and the working performance, reliability and service life of the LED can be improved.

The thermal resistance of the LED and the thermoelectric heat sink can be significantly reduced, so that the LED directly cools down directly through the heat and heat dissipation, and the effect is good, and the working performance, reliability and service life of the LED can be improved.

Example 2

The high-power LED heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer, as shown in FIG. 4-5, includes an aluminum substrate 21, an LED chip 2, a thermoelectric heat sink 4, and a microchannel heat exchanger 5. The LED chip 1 is mounted on an aluminum substrate 21 to form an LED light source portion. The aluminum substrate 21 is attached to the cold end of the thermoelectric heat sink 4, and the hot end of the thermoelectric heat sink 4 is connected to the cold end of the microchannel heat exchanger 5. The microchannel heat exchanger 5 uses nanofluidic fluid heat exchange, and the nanofluid working fluid is exported to be cooled by an air-cooled or liquid-cooled heat sink. An arc-shaped transparent cover 9 is mounted on the upper surface of the aluminum substrate 21, and the transparent cover 9 encloses the LED chip 1 on the aluminum substrate 21. A phosphor layer is disposed in the transparent cover 9. The hot end of the aluminum substrate 21 is connected to one end of a plurality of pairs of thermocouples 3 by a reflow soldering process, and the other end of the thermocouple 3 is connected to the cold end of the thermoelectric heat sink 4 by a reflow soldering process.

Preferably, the hot end of the thermoelectric heat sink 4 is connected with the microchannel heat exchanger 5 with a thermal conductive adhesive to facilitate heat conduction. The lead of the LED chip 1 is fixed to the aluminum substrate 21 by solder 23, and the interface between the heat generating end of the LED chip 1 and the thermoelectric heat sink 1 is fixed by the thermal conductive adhesive 11. An insulating layer 22 is provided between the aluminum substrate 21 and the LED chip, and the leads of the LED chip 1 are fixed to the pads of the aluminum substrate 21 by solder 23. The thermoelectric heat sink 4 conducts heat, and then the heat that is led out through the microchannel heat exchanger 1 is dissipated by the fluid heat dissipating mechanism.

The silicon substrate 21 and the thermoelectric heat sink 1 are an integrated package structure, and the heat releasing end of the LED chip 1 is directly in contact with the thermoelectric heat sink 4 to improve heat dissipation efficiency. The thermoelectric heat sink 4 and the microchannel heat exchanger 5 are connected by a solid crystal glue. The aluminum substrate 21, the LED chip 2, the thermoelectric heat sink 4, and the microchannel heat exchanger 5 are integrally fixed by a bottom plate and bolts 24 on both sides.

The rest of the structure of this embodiment is the same as that of the first embodiment. The invention discloses a device which can be used for LED cooling, and the cooling device comprises an aluminum substrate, a thermoelectric radiator and a microchannel radiator. The LED light source is mounted on the heat dissipation substrate to form an LED light source portion. The substrate 21 is mounted on the cold end of the thermoelectric heat sink 4; the hot end of the thermoelectric heat sink 4 is connected to the microchannel heat sink 5, and the microchannel heat sink 5 uses a nanofluid working medium to extract the working fluid. After cooling through the air-cooled or liquid-cooled radiator. The heat releasing end of the LED chip 1 is directly mounted on the thermoelectric heat sink of the thermoelectric heat sink, and closely adheres to the cold end of the thermoelectric heat sink of the thermoelectric radiator; the microchannel heat sink is closely attached to the hot end of the thermoelectric heat sink of the thermoelectric radiator, and the thermoelectric The heat sink heat sink is connected to the interface between the LED chip and the microchannel with a thermal adhesive, and the heat derived from the microchannel heat sink is dissipated by the fluid heat sink.

The above is only the preferred embodiment of the present invention, and the scope of the present invention cannot be limited thereto, that is, the simple equivalent changes and modifications made by the novel patent application scope and the new description content are all It is still within the scope of this new patent.

Claims

A high-power LED heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer, comprising a substrate, an LED chip, a thermoelectric heat sink and a microchannel heat exchanger, wherein the LED chip is mounted on a substrate; the heat of the substrate The end is connected to the cold end of the thermoelectric heat sink, and the hot end of the thermoelectric heat sink is connected to the cold end of the microchannel heat exchanger.
The high-power LED heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer according to claim 1, wherein the outlet and the inlet of the microchannel heat exchanger are respectively connected to the inlet and the outlet of the fluid heat dissipation cycle.
The high-power LED heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer according to claim 2, wherein the fluid heat dissipation cycle comprises a fluid pump and a fluid heat sink, and the fluid pump and the fluid heat exchanger are connected in series. A connection to the outlet and inlet of the microchannel heat exchanger forms a closed fluid heat dissipation cycle.
The high-power LED heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer according to claim 4, wherein the working fluid in the fluid heat dissipation cycle is a nanofluid working fluid.
The high-power LED heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer according to claim 4, wherein the flat tube of the microchannel heat exchanger is provided with a plurality of fine flows having an equivalent diameter of 10 to 1000 μm. Road.
The high-power LED heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer according to claim 3, wherein a fan for air cooling is disposed outside the fluid heat exchanger.
The high-power LED heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer according to claim 1, wherein the upper surface of the substrate is provided with a reflective cup-shaped recess, and the LED chip is mounted on the At the center of the groove, an upper surface of the silicon substrate is also mounted with an arc-shaped transparent cover.
The high-power LED heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer according to claim 1 or 7, wherein the substrate is an aluminum substrate or a silicon substrate.
The high-power LED heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer according to claim 1, wherein a hot end of the thermoelectric heat sink and the microchannel heat exchanger are connected by a thermal conductive adhesive.
The high-power LED heat dissipation structure based on thermoelectric refrigeration and microchannel heat transfer according to claim 8, wherein a hot end of the silicon substrate is connected to one end of a plurality of pairs of thermocouples, and the other end of the thermocouple is The cold junction of the thermoelectric heat sink.