CN107293633B - High heat flux density cooling device for high-power LED - Google Patents

Abstract

A high heat flux density cooling device for a high-power LED comprises at least one high-power LED device, wherein the high-power LED device at least comprises a metal-based circuit board, a heat dissipation substrate and a heat dissipation structure; the heat dissipation substrate comprises an LED mounting surface, a heat dissipation surface and a step mounting portion, wherein the LED mounting surface is provided with a first heat conduction structure; the first heat conduction structure is filled with heat conduction silicone grease, and the metal-based circuit board is embedded into the heat conduction silicone grease and fixed with the LED mounting surface; a second heat conducting structure is arranged on the heat radiating surface; the heat dissipation structure comprises a condensation shell, an evaporation cavity, a heat dissipation manifold and a reflux capillary core. The high heat flux density cooling device for the high-power LED supplements the heat dissipation of the radiant heat by increasing the heat dissipation area and using the transmission path of the conduction heat dissipation and the phase change heat dissipation, the heat is quickly dissipated, and the high heat flux density cooling device is suitable for being more than 60w/cm ² Efficient heat dissipation at high heat flux density.

Description

A High Heat Flux Cooling Device for High Power LED

technical field

The invention relates to the technical field of high-power LEDs, in particular to a high heat flux cooling device for high-power LEDs.

Background technique

As an active self-luminous device, LED is a solid-state lighting that does not burn filaments or gases. It has low power consumption, low operating voltage, high luminous brightness, long working life, and stable performance. It can work in extreme environments with little performance attenuation. It has been widely used due to its characteristics, but only 15% of the electric energy is converted into light energy during its working process, and the remaining 85% of the electric energy is almost completely converted into heat energy, which increases the temperature of the LED. As the temperature increases, not only the failure rate of LEDs increases greatly, but also the light decay of LEDs increases and the lifespan is shortened. Therefore, the thermal design of high heat flux is the core design that LEDs need most. For example, if a 10W white light LED has a photoelectric conversion efficiency of 15%, 8.5W of electrical energy will be converted into heat energy. If no heat dissipation measures are taken, the core temperature of the high-power LED will rise rapidly. When Tj rises above the maximum allowable temperature, the LED will be damaged by overheating.

For some high-power LED products at present, the heat flux density to be dissipated has reached 50-90w/cm ² , and the higher one has exceeded 150 w/cm ² . Coupled with the increasingly smaller product volume, the constraints encountered in the layout and design of the heat sink itself are becoming more and more serious. The traditional convective heat transfer and forced air cooling methods relying on single-phase fluid can only be used for products with a heat flux density not greater than 10w/cm ² . Now the test experience shows that the heat flux greater than 60w/cm ² can be called high heat flux.

In the prior art, the heat is dissipated from the tightly gathered LEDs by installing heat dissipating fins, forced-flow ventilation fans and special aluminum heat dissipating plates on the back of the substrate. For example, a heat dissipation layer is installed under the front LED mounting seat of the substrate, but the heat is transferred to the heat dissipation layer of the substrate through the LED seat, and then conducted to the back of the substrate by the heat dissipation layer, and the heat is taken away by the fan airflow. Forced airflow on the backside of the substrate to dissipate heat. Since the heat generated on the front side can only be taken away from the back side, the heat dissipation efficiency is poor, which affects the service life of the LED array device to a certain extent. There is also a plurality of copper tubes passing through the space between the LED arrays on the substrate to dissipate heat, but it is necessary to arrange a forced-flow ventilation fan on the back of the substrate to meet the cooling and heat dissipation requirements. This has resulted in a significant increase in the power consumption of the forced-flow ventilation fan, and has also increased the manufacturing cost.

At the same time, in order to cool the LEDs on the closely packed substrate, the cost of manufacturing and using the LEDs increases. For example, more than 70% of the electricity cost of LED array devices is consumed by forced air fans for cooling. The heat dissipation layer added during the manufacturing process also increases the cost of the LED array device.

Therefore, how to transfer the heat of the tightly packed LED array devices with low cost and high efficiency has become a common problem to be solved urgently in the promotion of LED array devices in the industry.

Contents of the invention

In view of the above-mentioned defects in the prior art, the object of the present invention is to provide a high heat flux cooling device for high-power LEDs, which can efficiently dissipate heat for LED substrates at extremely low cost without consuming electric energy.

The object of the present invention is achieved in that a high heat flux cooling device for high-power LEDs includes at least one high-power LED device, and the high-power LED device at least includes a metal-based circuit board,

It includes a heat dissipation substrate and a heat dissipation structure, and the high-power device and the heat dissipation structure are respectively installed and fixed on both sides of the heat dissipation substrate;

The heat dissipation substrate includes an LED installation surface, a heat dissipation surface and a stepped installation part, the LED installation surface is provided with a first heat conduction structure; the heat conduction silicone grease fills the first heat conduction structure, and the metal-based circuit board is embedded in the heat conduction silicone grease And fix it with the LED mounting surface;

The heat dissipation surface includes a left heat dissipation surface and a right heat dissipation surface. The left heat dissipation surface and the right heat dissipation surface are adjacent and symmetrically inclined to form concave ridges on both sides of the adjacent side. The heat dissipation surface is provided with a second heat conduction structure;

The heat dissipation structure includes a condensing shell, an evaporation cavity, a cooling fin and a return capillary core, the condensing shell is adiabatically fixed on the step installation part; the inner cavity formed by the condensing shell and the heat dissipation substrate is formed to evaporate cavity, the evaporation cavity is filled with a phase-changeable working medium; the inner wall and the outer wall of the condensation shell are provided with a plurality of cooling fins at intervals corresponding to each other;

The inner wall of the condensation shell is provided with a return capillary core, and the return capillary core can return the liquid working medium on the inner wall of the condensation shell to the heat dissipation surface.

Further, the first heat conduction structure includes a plurality of heat-absorbing pits arranged in an array at a certain interval on the LED mounting surface, and the second heat conduction structure includes a plurality of heat-dissipating pits arranged in an array at an interval at a certain interval on the heat dissipation surface .

Further, the heat dissipation structure also includes an axial flow fan and an air guide housing, and the condensation housing is provided with a top outer disc and a peripheral outer disc; an axial fan is fixedly installed in the air guide housing, and the air guide The casing can guide the outlet air flow of the axial flow fan along the top outer fin of the condensing shell and enter the peripheral outer fin.

Further, the condensing shell includes an integrally formed condensing top shell, a peripheral wall and a flange mounting part, the condensing top shell includes a left top and a right top, and the left top and right top are connected to form a horse ridge shape, the The ridgeline of the ridge is parallel to the concave ridge.

Further, the heat dissipating fins include outer fins and inner fins that are arranged one-to-one on the inside and outside of the wall of the condensing shell, and the outer fins include unconnected top outer fins and peripheral outer fins, the inner fins The discs include a top inner disc and a peripheral inner disc which are connected and integrally formed.

Further, the return capillary core includes an oblique return capillary core bundle, a vertical return capillary core bundle and a return capillary chip, and the oblique return capillary core bundle is fixed between the inner fins of the condensation housing, and makes the oblique return capillary core The bundle is closely attached to the inner wall of the condensing top shell, and vertical return capillary bundles are fixed at intervals corresponding to the ridge lines of the oblique return capillary bundles, and a return capillary chip is arranged on the heat dissipation surface of the heat dissipation substrate. The lower ends of the core bundles and the vertical return capillary core bundles abut against the return capillary chips respectively.

Further, the air guide housing is provided with a fan fixing part and an air guide part. When the outlet flange of the air guide housing is fixed on the flange mounting part of the condensation housing, the surrounding wall of the air guide part It is arranged close to the outer discs, and the peripheral wall of the air guide part is provided with a plurality of grid holes at intervals corresponding to the positions of the outer discs. The air guide housing guides the outlet airflow of the axial flow fan along the space between the top outer discs. The outer side flows through the spaces between the peripheral fins and out through the grid holes.

Further, the fan fixing part includes support ribs integrally connected with the wind guide housing and an inverted T-shaped hub fixing body, the hub fixing body includes an integrally formed T-shaped cap and a motor shaft fixing tube, and the axial flow fan includes The hub and a plurality of rotating blades integrally connected with the hub, the hub combined with the drive shaft of the motor are rotatably arranged in the motor shaft fixing tube through tapered roller bearings.

Further, the T-shaped cap has an air guide edge, and the angle between the air guide edge and the axis of the motor shaft fixing tube constitutes an air guide angle, and the air guide angle is 30°-60°.

Further, the heat dissipation structure further includes a tube-shaped evaporator, and the tube-shaped evaporator is hermetically installed in the installation hole of the heat dissipation substrate; the tube-shaped evaporator includes an evaporation part and a condensation part, and the condensation part has an opening The open end extends above the liquid level of the working medium in the evaporation chamber; the tube-shaped evaporator is equipped with the phase-changeable working medium.

Compared with the prior art, the present invention is a cooling device with high heat flux density for high-power LEDs, so that the heat of the base of the high-power LED device and the heat of high heat flux density in the LED aggregation group can be quickly dissipated, greatly increasing the heat dissipation area, and can also be used for conduction. The transfer path of heat dissipation and phase change heat dissipation, supplementary radiation heat dissipation, is suitable for effective heat dissipation with high heat flux density greater than 60w/cm ² .

Description of drawings

Fig. 1 is a main cross-sectional view of the present invention applied to a high-power LED.

Fig. 2 is a front sectional view of a high heat flux cooling device for high-power LEDs according to the present invention.

Fig. 3 is a bottom view of a high heat flux cooling device for high-power LEDs according to the present invention.

Fig. 4 is a front sectional view of a condensing shell of a high heat flux cooling device for high-power LEDs according to the present invention.

FIG. 5 is a front sectional view of an air guide housing of a high heat flux cooling device for high-power LEDs according to the present invention.

Reference numerals in the above figures:

100 high-power LED device, 101 LED chip, 102 inner heat sink, 103 metal-based circuit board, 104 packaging lens, 105 Z-shaped electrode, 106 insulating layer, 200 heat dissipation structure,

1 heat dissipation substrate, 2 first heat conduction structure, 2.1 heat absorption pit, 3 annular rib, 4 heat conduction silicone grease, 6 left heat dissipation surface, 7 right heat dissipation surface, 8 second heat conduction structure, 8.1 heat dissipation pit

1.1 LED mounting surface, 1.2 heat dissipation surface, 1.3 step mounting part, 1.4 inner concave ridge, 1.5 side wall surface

20 condensing case, 21 condensing top case, 21.1 top left, 21.2 top right, 22 peripheral wall, 23 flange mounting part

30 evaporation chamber, 31 working medium

40 cooling fins, 41 outer fins, 41.1 top outer fins, 41.2 outer fins, 42 inner fins, 42.1 top inner fins, 42.2 inner fins

50 return capillary, 51 oblique return capillary, 52 vertical return capillary, 53 return capillary chip

60 Axial flow fan, 61 Air guiding shell, 62 Support rib, 63 Wheel hub fixing body, 64 Air guiding edge

60.1 hub, 60.2 rotating blade, 60.3 tapered roller bearing

61.1 Fan fixing part, 61.2 Air guide part, 61.3 Grille hole

63.1 T-shaped cap, 63.2 Motor shaft fixing tube, α guide angle

70 tube evaporator, 70.1 evaporating section, 70.2 condensing section

Detailed ways

Embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, but they are not used to limit the scope of the present invention.

As shown in the figure, a high-power LED device 100 includes an LED chip 101, an inner heat sink 102, a metal-based circuit board 103, and a packaging lens 104. The inner heat sink 102 is fixed on the metal-based circuit board 103 by high thermal conductivity silver glue, The inner heat sink 102 includes a top portion and a step portion, the LED chip 101 is fixed on the top portion of the inner heat sink 102 by high thermal conductivity silver glue, the step portion of the inner heat sink 102 is fixed with an insulating layer 106, and the insulating layer 103 is fixed outside There is a Z-shaped electrode 105; the overlapping end of the Z-shaped electrode is fixed on the insulating layer 106, and the sealed end of the Z-shaped electrode is fixed on the metal-based circuit board 103 by high thermal conductivity silver glue, and the Z-shaped electrode passes through The gold wire is connected to the LED chip 101 ; the encapsulation lens 104 seals and fixes the overlapping ends of the LED chip 101 , the gold wire and the Z-shaped electrode 104 on the step portion of the inner heat sink 102 . The LED chip 101, the inner heat sink 102 and the metal-based circuit board 103 form a heat conduction path.

A high-power LED array device 300 includes a plurality of high-power LED devices 100 and a heat dissipation substrate 1, and the high-power LED devices 100 are fixed on the heat dissipation substrate 1 in an array with a certain row spacing Y and column spacing X;

A high heat flux cooling device for high-power LED array devices, comprising a heat dissipation substrate 1 and a heat dissipation structure 200 installed on the heat dissipation substrate 1, the heat dissipation substrate 1 includes an LED mounting surface 1.1, a heat dissipation surface 1.2 and a stepped installation part 1.3, the LED mounting surface 1.1 is provided with a first heat conduction structure 2 and an annular rib 3, and the annular rib 3 is arranged around the first heat conduction structure 2; the first heat conduction structure 2 includes a certain array spacing arranged on the LED The heat-absorbing pit 2.1 on the mounting surface 1.1 is filled with a certain thickness of heat-conducting silicone grease 4 in the annular rib 4, so that the heat-conducting silicone grease 5 fills the heat-absorbing pit 2.1 and must be embedded higher than the LED mounting surface 1.1. The embedding thickness is at least 1.5 times greater than the thickness of the metal-based circuit board 103 . The metal-based circuit board 103 is embedded in the heat-conducting silicone grease 4 and fixed with the heat-dissipating substrate 1 . Preferably, the heat-absorbing pits 2.1 are a cube, and the array spacing is the side length of the cube;

The heat dissipation surface 1.2 is V-shaped, including a left heat dissipation surface 6 and a right heat dissipation surface 7, and the included angle between the left heat dissipation surface 6 and the right heat dissipation surface 7 and the horizontal plane is 2-5°. The heat dissipation surface 1.2 is provided with a second heat conduction structure 8, and the second heat conduction structure 8 includes heat dissipation pits 8.1 arranged on the heat dissipation surface 1.2 at intervals in a certain array. Preferably, the heat dissipation pits 8.1 are a cube, and the array spacing is the side length of the cube.

The side wall surface 1.4 of the heat dissipation surface 1.2 and the outer edge surface of the heat dissipation surface of the substrate 1 form a stepped installation portion 1.3.

The heat dissipation structure 200 includes a condensing shell 20, the condensing shell 20 includes an integrally formed condensing top shell 21, a peripheral wall 22 and a flange mounting part 23, the flange mounting part 23 is fixed on the step mounting part 1.3 Above, a heat insulating pad 24 is provided between the flange mounting portion 23 and the stepped mounting portion 1.3; and the peripheral wall 22 is tightly attached to the side wall surface 1.5 of the heat dissipation surface 1.2. The condensing top case 21 includes a left top 21.1 and a right top 21.2, the left top 21.1 and the right top 21.2 are connected to form a horse ridge shape, and the condensing top case 21 is made of fast heat conduction material, such as copper, aluminum alloy or graphite vinyl or other high thermal conductivity materials.

The heat dissipation structure 2 further includes an evaporation chamber 30 , the internal cavity formed by the condensation shell 20 and the heat dissipation substrate 1 constitutes the evaporation chamber 30 , and the evaporation chamber 30 is evacuated and filled with a phase-changeable working medium 31 . The perfusion amount of the working medium is optimally 15-25% of the total volume of the evaporation chamber 13 .

The heat dissipation structure 2 also includes a heat dissipation fin 40, and the heat dissipation fin 40 includes an outer fin 41 and an inner fin 42 corresponding to the inside and outside of the wall, and the outer fin 41 includes a top outer fin 41.1, Peripheral outer disc 41.2, said inner disc 42 includes a top inner disc 42.1 and a peripheral inner disc 42.2, said outer disc 41 and inner disc 42 correspond to each other along the outer surface and inner surface of the condensing top shell 21 respectively The fonts are arranged at intervals, the top outer discs 41.1 are aligned with the peripheral outer discs 41.2 one by one, and the top inner discs 42.1 are aligned with the peripheral inner discs 42.2. The peripheral outer disc 41.2 is not connected to the top outer disc 41.1. The peripheral disc 42.2 is connected with the top inner disc 42.1 and integrally formed;

The heat dissipation structure 2 further includes a return capillary wick 50 , and the return capillary wick 50 brings the liquid working medium back to the heat dissipation surface 1 . Specifically, oblique reflow capillary cores 51 are fixed between the adjacent inner discs 42, and the oblique reflow capillary core bundles 51 are fixed on the adjacent inner discs 42 by spot welding, so that the oblique The return capillary bundles are close to the inner wall of the condensing top case 21 ; vertical return capillary bundles 52 are fixed at intervals between the oblique return capillary bundles 51 . The heat dissipation surface 1.2 of the heat dissipation substrate 1 is provided with a return capillary chip 53, and the lower ends of the oblique return capillary bundles 51 and the vertical return capillary bundles 52 abut against the return capillary chips 53 respectively.

The heat dissipation structure 200 also includes an axial flow fan 60 and an air guide housing 61, the air guide housing 61 is provided with a fan fixing part 61.1 and an air guide part 61.2, and the axial flow fan 60 is fixed on the fan fixing part 61.1, specifically, the fan fixing part 61.1 includes a support rib 62 integrally connected with the wind guide housing and an inverted T-shaped hub fixing body 63, and the hub fixing body 63 includes an integrally formed T-shaped cap 63.1 and a motor shaft fixing Tube 63.2. The axial flow fan 60 includes a hub 60.1 and a plurality of rotating blades 60.2 integrally connected with the hub, and the hub 60.1 combined with the drive shaft of the motor is fixed to the motor shaft fixed on the fan fixing part 61.1 through a tapered roller bearing 60.3. Tube 63.2. Preferably, the T-shaped cap 63.1 has an air guiding edge 64, and the included angle between the air guiding edge 64 and the axis of the motor shaft fixing tube is 30°-60° for the air guiding angle α.

When the outlet flange of the air guiding housing 61 is fixed on the flange mounting portion 23 of the condensing housing 20, the peripheral wall of the air guiding part 61.2 is arranged in close contact with the peripheral disc 41.2. The surrounding wall of the air guide part 61.2 is provided with a plurality of grid holes 61.3 at intervals corresponding to the positions of the outer discs 41.2, and the air guide housing 61 guides the outlet airflow of the axial flow fan 60 along the space between the top outer discs 41.1. The outer side flows through the space between the peripheral discs 41.2 and then out through the grid hole 61.3. The wind guiding housing has an inlet flange and an outlet flange, and bolts pass through the inlet flange and the outlet flange to fix with the flange mounting part 12 .

The heat dissipation structure 200 also includes a tubular evaporator 70 . The tube-shaped evaporator 70 is hermetically installed on the mounting hole of the heat dissipation substrate 1; the tube-shaped evaporator 70 includes an evaporating part 70.1 and a condensing part 70.2, and the condensing part 70.2 has an open end extending beyond the evaporation The liquid level of the working medium in the cavity 30 is 5-10mm; the evaporation part 70.1 has a closed end, and the closed end is preferably semi-spherical or flat or other three-dimensional decorative shapes; the evaporation part 70.1 of the tubular evaporator passes through the heat dissipation substrate Mounting holes 1.3 are provided between the LED arrays.

The tube-shaped evaporator 70 is equipped with a phase-changeable working medium; the perfusion amount of the phase-changeable working medium in the tube-shaped evaporator 70 is 12-25% of the total volume of the tube-shaped evaporator 70; the perfusion of the working medium The optimum amount is 15% of the total volume of the tubular evaporator 70.

The evaporation part 70.1 of the tubular evaporator 70 and the evaporation chamber 30 are respectively provided with a rectangular observation window 71, and the lower edge of the observation window 71 is located at 1/5 of the height of the tubular evaporator 70; The liquid level of the liquid, if the internal liquid level is lower than the lower edge of the observation window, the working medium on the surface is less, and the working medium needs to be replenished.

When the LED array device 300 or the high-power LED device 100 is working, as the gathered LED light-emitting elements continuously release heat, the inner heat sink 102 directly conducts the heat to the heat dissipation substrate 1, and the radiant heat of the packaging lens 104 is transferred to the tubular evaporator The evaporation part 70.1 of 70, the phase-change working medium in the evaporation chamber 30 and the evaporation part 70.1 changes from liquid to gas in the evaporation section, and the gas evaporates upwards until it condenses on the condensing top shell 21 and the inner disc 42, by The gas turns into liquid, and as the liquid gathers gradually, part of the liquid flows back to the lowest center part of the heat dissipation substrate 1 from the vertical return capillary bundle. The heat released on the condensing top shell 21 and the inner manifold 42 is quickly dissipated in the air by the outer manifold 41 .

The cooling device of the LED array device dissipates heat through two ways, one is heat conduction, and the heat conduction is conducted from the inner heat sink to the heat dissipation plate, and the heat dissipation plate dissipates part of the heat through the evaporation chamber 30 through the heat dissipation fins 40 to In the air; second, radiant heat, radiant heat is the heat generated by the radiation of the packaged lens 104, and this part of the heat is converted from liquid to gas by the working medium in the tubular evaporator 70, absorbing the heat of the tubular evaporator 70. The evaporation chamber 30 and the tube-shaped evaporator 70 work together to take away the conduction heat and the radiation heat respectively, and jointly maintain the low-temperature working environment of the LED array device 300 .

For a single high-power LED, the tubular evaporator 70 can be omitted, and only the heat dissipation structure 200 including the evaporating chamber 30 can be used.

The high heat flux cooling device for high-power LEDs substantially solves the technical problem of "how to transfer high heat flux heat of high-power LED devices at low cost and high efficiency" through the following technologies:

1) The heat conduction structure increases the heat transfer area and forms a heat conduction path without micro-gap

Both sides of the heat dissipation substrate 1 are provided with heat conduction structures. The LED mounting surface has a plurality of heat-absorbing pits in a spaced array, and the heat dissipation surface has a plurality of heat dissipation pits in a spaced array. The heat from the heat sink in the high-power LED is conducted to the metal-based circuit board. The heat of the base circuit board is transferred to the heat-conducting silicone grease, and the heat-conducting silicone grease contacts the heat-dissipating substrate 1 through many longitudinal heat-absorbing pits, which greatly increases the heat transfer area for the heat-dissipating substrate 1 to absorb heat from the heat-conducting silicone grease, assuming that the pits are the sides The cube with length a is originally the heat-absorbing area of a ² , but after pressing out the pits of the cube, the heat-absorbing area becomes 5a ² , and the heat-absorbing area increases by 4 times. The heat dissipation pit also increases the heat transfer area from the heat dissipation substrate to the working medium by 4 times.

The LED mounting surface of the heat dissipation substrate is in contact with thermally conductive silicone grease, and the heat dissipation surface is in contact with liquid working medium. There is no micro-gap on the contact surface, and a heat conduction path seamlessly connected with the heat transfer area is constructed.

2) The cooperation of the condensing shell and the inner disc builds the first heat dissipation path, and the cooperation of the air guide shell and the outer disc builds the second heat dissipation path.

The condensing shell 20 and the heat dissipation substrate form an evaporation cavity, and the phase-change working medium in the evaporating cavity changes from a liquid state to a gaseous state to absorb heat. The heat is transferred to the inner wall of the condensing shell and the inner fins, forming a phase change heat dissipation path as the first heat dissipation path; the heat of the inner wall and the inner fins is conducted to the outer fins and the outer wall, and the outer fins and guides of the condensing shell The air heat dissipation path formed by the cooperation of the wind housing is the second heat dissipation path, and the second heat dissipation path is closely connected with the first heat dissipation path to send heat to the ambient air.

3) The tubular evaporator absorbs radiation heat dissipation and supplements conduction heat dissipation

The tube-shaped evaporator absorbs the heat generated by long-time radiation from the LED package lens 104. Although the heat dissipation substrate 1 can meet the working temperature requirements of the LED chip 101, after long-time use, the radiation heat from the package lens 104 irradiated for a long time will cause Conversely, heating the temperature in the packaging lens 104 will cause the temperature in the packaging space of the LED chip 101 to rise, which is not allowed. The tubular evaporator takes away the radiant heat of the packaging lens 104 , so that the gap temperature of the LED array is lowered, which indirectly prevents the temperature of the packaging lens 104 itself from rising, thereby ensuring a low working temperature in the packaging space of the LED chip 101 . This is a strong supplement to the conduction heat dissipation from the inner heat sink 102 to the metal-based circuit board 101 .

It is the synergistic effect of the above three improvements that makes the heat of the base of the high-power LED device and the heat of the high heat flux in the LED cluster dissipate rapidly, greatly increasing the heat dissipation area, and using the transfer path of conduction heat dissipation and phase change heat dissipation, supplementing Radiant heat dissipation greatly improves heat transfer efficiency.

Claims (5)

1. A high heat flux cooling device for high-power LEDs, comprising at least one high-power LED device (100), the high-power LED device at least comprising a metal-based circuit board (103), characterized in that, It includes a heat dissipation substrate (1) and a heat dissipation structure (200), and the high-power LED device and the heat dissipation structure are respectively installed and fixed on both sides of the heat dissipation substrate (1); The heat dissipation substrate (1) includes an LED installation surface (1.1), a heat dissipation surface (1.2) and a step installation portion (1.3), and the LED installation surface (1.1) is provided with a first heat conduction structure (2); heat conduction silicone grease ( 4) filling the first heat-conducting structure (2), the metal-based circuit board (103) is embedded in the heat-conducting silicone grease (4) and fixed to the LED mounting surface (1.1); The heat dissipation surface (1.2) includes a left heat dissipation surface (6) and a right heat dissipation surface (7), and the left heat dissipation surface (6) and the right heat dissipation surface (7) are adjacent and symmetrically arranged on both sides of the adjacent side to form a concave a ridge (1.4), the heat dissipation surface (1.2) is provided with a second heat conduction structure (8); The heat dissipation structure (200) includes a condensing shell (20), an evaporation chamber (30), a heat dissipation fin (40) and a return capillary core (50), and the condensing shell (20) is adiabatically fixed on the stepped installation part On (1.3); the internal cavity formed by the condensing housing (20) and the heat dissipation substrate (1) constitutes an evaporation cavity (30), and the evaporation cavity (30) is filled with a phase-changeable working medium (31 ); the inner wall and the outer wall of the condensing housing (20) are spaced with a plurality of cooling fins (40) correspondingly; The inner wall of the condensation shell is provided with a return capillary core (50), and the return capillary core (50) can return the liquid working medium on the inner wall of the condensation shell to the heat dissipation surface (1.2); The first heat conduction structure (2) includes a plurality of heat-absorbing pits (2.1) arranged in an array at a certain interval on the LED mounting surface (1.1), and the second heat conduction structure (8) includes an array at a certain interval and arranged at intervals on the LED mounting surface (1.1). Multiple heat dissipation pits (8.1) on the heat dissipation surface (1.2); The heat dissipation structure (200) also includes an axial flow fan (60) and an air guide housing (61), and the condensation housing (20) is provided with a top outer disc (41.1) and a peripheral outer disc (41.2); the An axial flow fan (60) is fixedly installed in the air guide housing (61), and the air guide housing (61) can guide the outlet airflow of the axial flow fan along the top outer disc of the condensing housing to enter the peripheral disc; The condensing shell (20) includes an integrally formed condensing top shell (21), a surrounding wall (22) and a flange mounting part (23), and the condensing top shell (21) includes a left top (21.1) and a right top ( 21.2), the left top (21.1) and the right top (21.2) are connected to form a horse ridge, and the horse ridge line of the horse ridge is parallel to the inner concave ridge (1.4); The radiating fins (40) include outer fins (41) and inner fins (42) that are arranged one-to-one on the inside and outside of the wall of the condensing shell, and the outer fins (41) include unconnected top outer fins (41) A disc (41.1) and a peripheral disc (41.2), the inner disc (42) includes a top inner disc (42.1) and a peripheral inner disc (42.2) which are connected and integrally formed; The return capillary core (50) includes an oblique return capillary core bundle (51), a vertical return capillary core bundle (52) and a return capillary chip (53), and the oblique return capillary core bundle (51) is fixed on the condensation housing ( 20) between the inner discs (42), and make the oblique return capillary core bundle close to the inner wall of the condensation top shell (21), and the corresponding horse ridge line positions of the oblique return capillary bundle (51) are fixed at intervals The vertical reflow capillary bundle (52) is provided with a reflow capillary chip (53) on the heat dissipation surface (1.2) of the heat dissipation substrate, the lower end of the oblique reflow capillary bundle (51) and the vertical reflow capillary bundle (52) The lower ends abut against the return capillary chips (53) respectively. 2. The high heat flux cooling device for high-power LEDs according to claim 1, characterized in that, the air guide housing (61) is provided with a fan fixing part (61.1) and an air guide part (61.2), when When the outlet flange of the air guide housing (61) is fixed on the flange mounting part (23) of the condensing housing (20), the peripheral wall of the air guide part (61.2) is set in close contact with the peripheral disc (41.2) , the surrounding wall of the air guide part (61.2) is provided with a plurality of grid holes (61.3) at intervals corresponding to the positions of the peripheral discs (41.2), and the air guide housing (61) guides the outlet airflow of the axial flow fan (60) Flow along the space between the top outer discs (41.1) to the outside along the space between the peripheral outer discs (41.2) and then flow out from the grid hole (61.3). 3. The high heat flux cooling device for high-power LEDs according to claim 2, characterized in that, the fan fixing part (61.1) includes a support rib (62) integrally connected with the air guide housing and an inverted T-shaped hub A fixed body (63), the hub fixed body (63) includes an integrally formed T-shaped cap (63.1) and a motor shaft fixing tube (63.2), and the axial flow fan (60) includes a hub (60.1) and an integral body with the hub A plurality of rotating blades (60.2) are connected, and the hub (60.1) combined with the drive shaft of the motor is rotatably arranged in the motor shaft fixing tube (63.2) through a tapered roller bearing (60.3). 4. The high heat flux cooling device for high-power LEDs as claimed in claim 3, characterized in that, the T-shaped cap (63.1) has an air guide edge (64), and the air guide edge (64) and The included angle between the axes of the motor shaft fixing pipe constitutes a wind guide angle (α), and the wind guide angle (α) is 30°˜60°. 5. The high heat flux cooling device for high-power LEDs according to claim 1, characterized in that, the heat dissipation structure (200) further comprises a tubular evaporator (70), and the tubular evaporator (70) Hermetically installed in the installation hole of the heat dissipation substrate (1); the tubular evaporator (70) includes an evaporation part (70.1) and a condensation part (70.2), the condensation part (70.2) has an open end, and the open end extends It is higher than the liquid level of the working medium in the evaporation chamber (30); the tubular evaporator (70) is equipped with the phase-changeable working medium (31).

Images