WO2018161462A1

WO2018161462A1 - Flat plate heat pipe, micro-channel heat dissipation system and terminal

Info

Publication number: WO2018161462A1
Application number: PCT/CN2017/087474
Authority: WO
Inventors: 陈彦君
Original assignee: 华为技术有限公司
Priority date: 2017-03-08
Filing date: 2017-06-07
Publication date: 2018-09-13
Also published as: CN108885066B; CN108885066A

Abstract

Disclosed are a flat plate heat pipe (12), a micro-channel heat dissipation system and a terminal. In the flat plate heat pipe (12), an insulating material (42) is provided between a liquid absorption core (43) and an inner surface of a housing (44). The liquid absorption core (43) accesses to a first electric potential, the housing (44) accesses to a second electric potential, and an electric potential difference exists between the first electric potential and the second electric potential. In the micro-channel heat dissipation system, a top plate (611) and a bottom plate (612) are made of a metal material, and an insulating side plate (601) encircles the edge of the two. The top plate (611) accesses to a first electric potential, the bottom plate (612) accesses to a second electric potential, and an electric potential difference exists between the first electric potential and the second electric potential. Using the characteristics of electric field energy enhanced boiling and forced convection heat transfer, the liquid absorption core (43) and the housing (44) in the flat plate heat pipe (12) serving as electrodes, and the top plate (611) and a micro-channel heat transfer face (613) in the micro-channel heat dissipation system serving as electrodes, an electric field is introduced to enhance heat transfer, and by improving the heat exchange coefficient and critical heat flow density, the heat dissipation capacity is greater, thereby improving the heat reliability and heat experience of the flat plate heat pipe (12) and the micro-channel heat dissipation system.

Description

Flat heat pipe, microchannel cooling system and terminal

This application claims the priority of the Chinese patent application filed by the Patent Office of the State Intellectual Property Office of China, the application number is 201710135105.1, and the invention name is "a planar heat dissipation structure, heat dissipation method and terminal" on March 8, 2017. This is incorporated herein by reference.

Technical field

The present application relates to the field of heat transfer technology, and more particularly to a flat heat pipe, a microchannel heat dissipation system, and a terminal.

Background technique

With the rapid development of smart terminal products (including notebooks, tablets and mobile phones), the frequency of their processors is getting higher and higher, and the power consumption is getting larger and larger, in order to ensure the reliability of electronic components and improve consumers. Thermal comfort and experience have made it important to develop heat sinks with excellent heat transfer properties.

In the prior art, commonly used electronic heat sink components include heat pipes and microchannel heat exchangers. The heat pipe is widely used in terminals such as notebooks because of its high thermal conductivity and excellent temperature uniformity due to phase change boiling and condensation heat transfer. The heat transfer coefficient of the microchannel heat exchanger (ie, the heat exchanger with a channel equivalent diameter of 10-1000 μm) can be increased by 50-100% on the basis of the centimeter heat exchanger. In addition, due to its small size, it is particularly suitable for heat dissipation of electronic devices. However, due to the increasing frequency and power consumption of the processor of the intelligent terminal product, the heat generated per unit time is getting higher and higher, and the existing electronic heat sink device cannot meet the heat dissipation requirement of the high frequency processor.

Summary of the invention

Embodiments of the present application provide a flat heat pipe and a microchannel heat dissipation system. The use of an electric field can enhance the characteristics of convective heat transfer, and introduce an electric field to enhance heat dissipation to improve the heat transfer performance of the electronic heat sink.

In a first aspect, an embodiment of the present application provides a flat heat pipe. The flat heat pipe comprises a casing, a wick and a working medium, the casing and the wick are made of a metal material, and the wick and the working medium are placed inside the casing. The wick is fixed to the inner surface of the casing, and the first insulating material is disposed between the wick and the inner surface of the casing. The wick is connected to the first potential, the casing is connected to the second potential, and the first potential and the second potential have a potential difference. The flat heat pipe provided by the embodiment of the present invention utilizes an electric field energy to enhance the characteristics of the boiling and forced convection heat exchange process, and uses the liquid absorbing core and the shell as electrodes to introduce an electric field to enhance heat dissipation, and improve the heat transfer coefficient and critical heat flux density of the flat heat pipe. The heat dissipation capability is more powerful, and is applied to the terminal electronic device, which can effectively reduce the temperature rise of the device and the whole machine.

In one possible design, the wick enters the first potential through the first lead. A lead hole is disposed on the housing, and the first lead penetrates the lead hole, and the lead hole is sealingly connected to the first lead.

In one possible design, a filter capacitor is inserted in the first lead, and the filter capacitor is used to eliminate electromagnetic interference.

In one possible design, the second potential is zero potential. With this design, the metal casing is grounded to obtain a good electromagnetic shielding effect.

In one possible design, the first potential is constant and the second potential is adjustable. Alternatively, the second potential is constant and the first potential is adjustable. Alternatively, the first potential and the second potential are unchanged. Alternatively, both the second potential and the second potential are adjustable. By adjusting the electric field strength, active control of the temperature of the flat heat pipe can be achieved.

In one possible design, the wick and the first lead surface are covered with a second insulating material.

In one possible design, the first lead is an insulated shield.

In one possible design, the first insulating material is a strip of glue.

In one possible design, the wick is a capillary structure formed by a single or multiple layers of wire mesh.

In one possible design, the working medium is water or a refrigerant.

In one possible design, the metallic material is copper, aluminum or stainless steel.

In a second aspect, the present application provides a microchannel heat dissipation system. The microchannel cooling system includes a microchannel, a working medium, a circulation conduit, a micropump, and a condenser. The utility model further comprises a bottom plate, wherein the bottom plate is provided with a micro channel, and a top plate is arranged opposite to the bottom plate, the two ends of the top plate are respectively provided with an inlet and an outlet, and the inlet and the outlet are connected by a circulation pipe, and the micro-pump and the condensation are also connected in the circulation pipe. Device. The edges of the top and bottom plates are enclosed with insulated side panels. The top plate and the bottom plate are made of a metal material, the top plate is connected to the first potential, the bottom plate is connected to the second potential, and the first potential has a potential difference from the second potential. A microchannel heat dissipation system provided by an embodiment of the present invention utilizes an electric field energy to enhance the characteristics of a boiling and forced convection heat exchange process, and uses a heat exchange surface of a top plate and a microchannel as an electrode to introduce an electric field to enhance heat dissipation, and to improve a microchannel heat dissipation system. The heat transfer coefficient and the critical heat flux density make the heat dissipation capability more powerful, and can be applied to the terminal electronic equipment, which can effectively reduce the temperature rise of the device and the whole machine.

In one possible design, the bottom plate is connected to the shield, the shield is made of a metal material, and the bottom plate is connected to the second potential through the shield.

In one possible design, the shield is a wire mesh.

In one possible design, the top plate is connected to the first potential through the first lead. A filter capacitor is connected to the first lead, and the filter capacitor is used to eliminate electromagnetic interference.

In one possible design, the first lead is an insulated shield.

In one possible design, the second potential is zero potential. With this design, the shield and the bottom plate are grounded to obtain a good electromagnetic shielding effect. In one possible design, the first potential is constant and the second potential is adjustable. Alternatively, the second potential is constant and the first potential is adjustable. Alternatively, the first potential and the second potential are unchanged. Alternatively, both the second potential and the second potential are adjustable. With this design, the active control of the heat transfer surface temperature of the microchannel can be achieved by adjusting the electric field strength.

In one possible design, the heat exchange surface of the microchannel is triangular zigzag. In this design, the microchannel heat exchange surface is designed as a profiled wall surface, which can effectively increase the heat exchange area.

In one possible design, the material of the insulating side panels is polyimide.

In one possible design, the top plate and the first lead surface are covered with an insulating material. With this design, the top plate and the first lead can be prevented from being short-circuited.

In one possible design, the material of the circulation pipe is rubber.

In one possible design, the working medium is water or a refrigerant.

In a third aspect, an embodiment of the present application provides a terminal. The terminal includes the flat heat pipe provided by the above first aspect or the microchannel heat dissipation system provided by the above second aspect.

Compared with the prior art, the flat heat pipe, the microchannel heat exchange system and the terminal provided by the embodiments of the present application can enhance the characteristics of convective heat transfer by using an electric field, and the wick and the shell are used as electrodes in the flat heat pipe, and In the microchannel heat exchange system, the heat exchange surface of the top plate and the microchannel is used as an electrode to introduce an electric field to enhance heat exchange. By increasing the heat transfer coefficient and critical heat flux density of the flat heat pipe and the microchannel heat dissipation system, the heat dissipation capability is more powerful and applied to the terminal. In electronic equipment, Effectively reduce the temperature rise of the device and the whole machine. At the same time, by adjusting the electric field strength, active control of the temperature of the flat heat pipe and the microchannel heat dissipation system can be achieved. The insulation and access filtering device of the flat heat pipe and the insulation and access filtering device of the top plate of the micro channel heat dissipation system can avoid short circuit and eliminate electromagnetic interference. Grounding the metal shell of the flat heat pipe and grounding the bottom plate and the shield of the microchannel heat dissipation system can obtain a good electromagnetic shielding effect, thereby effectively improving the thermal reliability and thermal experience of the flat heat pipe and the microchannel heat dissipation system.

DRAWINGS

FIG. 1 is a schematic diagram of an application scenario provided by an embodiment of the present application;

2 is a schematic view of the action of an electric field on a bubble during an electric field enhanced heat transfer process;

3 is a schematic view showing the operation of a flat heat pipe in the prior art;

4(a)-(d) are schematic structural views of a flat heat pipe provided by an embodiment of the present application;

5 is a schematic structural view of a microchannel in the prior art;

FIG. 6 is a schematic structural diagram of a microchannel heat dissipation system according to an embodiment of the present application.

detailed description

The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application.

FIG. 1 is a schematic diagram of an application scenario provided by an embodiment of the present application. As shown in FIG. 1, the heat generated by the chip 13 of the notebook computer 11 is transferred to the outside environment by the flat heat pipe 12.

The flat heat pipe or microchannel heat dissipation system provided by the embodiment of the present application can be applied to the heat dissipation process of the chip, for example, a notebook chip or a base station chip, and the flat heat pipe or micro channel proposed by the present application can be used as long as there is a heat source. cooling system. The heat is transferred to the external environment through the flat heat pipe or the microchannel heat dissipation system, and the heat is actively induced by the introduction of the electric field to improve the heat transfer coefficient and the critical heat flow density of the flat heat pipe and the microchannel heat dissipation system, so that the heat dissipation capability is more powerful, and the temperature of the chip and the like Lower, improve the thermal reliability and thermal experience. It should be noted that the embodiment of the present application is not limited to the electronic heat dissipation application, and can also be used for the heat dissipation process of other scene heat sources, such as aerospace thermal control.

Figure 2 is a schematic diagram of the action of an electric field on a bubble during an electric field enhanced heat transfer process. As shown in FIG. 2, since the dielectric constants of the gas and the liquid are inconsistent, the bubble 21 in the fluid generates a dielectrophoretic force 23 under the action of the electric field 24 generated by the high potential electrode 22 and the ground electrode 25. In the electric field, the electric field force received by the fluid includes three kinds, and the electrophoresis force, the dielectrophoretic force and the electrostrictive force are sequentially followed by the equal sign of the equation (1).

Where F _e represents the electric field force, ρ _e represents the charge density, E represents the electric field strength, ε represents the dielectric constant, T represents the fluid temperature, and ρ represents the fluid density.

Electric field enhanced heat transfer is an active method of enhancing heat transfer by applying an electric field in a fluid and utilizing the coupling between the electric field, the flow field and the temperature field. Its strengthening effect on boiling heat transfer can reach about 3.4 times. Among them, the boiling heat transfer includes a boiling heat transfer process and a condensation heat transfer process. The boiling heat transfer process refers to the convective heat transfer process in which heat is transferred from the wall to the liquid to vaporize the liquid. During this process, small bubbles present inside the liquid and on the wall of the vessel act as bubbles, and the vapor in the small bubbles is saturated. As the temperature rises after the liquid absorbs heat, the saturated vapor pressure in the small bubbles increases correspondingly, and the bubbles continue to swell. When the saturated vapor pressure is increased to the same as the external pressure, the bubble suddenly expands, and rapidly rises to the liquid surface and vaporizes under the action of buoyancy. In the boiling heat transfer process, by applying an electric field to the fluid, it can be significantly reduced The small bubble grows waiting time and the bubble leaves the diameter D, and at the same time, enhances the bubble generation frequency and nucleation density, thereby accelerating the boiling heat transfer process. The condensation heat transfer process refers to the latent heat (the abbreviation of latent heat of phase change) when the vapor is in contact with a wall whose temperature is lower than its saturation temperature. It refers to the absorption or release of a substance from one phase to another under isothermal isostatic pressure. Heat, here refers to the convective heat transfer process that is transmitted to the wall to condense itself when the working medium changes from the gas phase to the liquid phase. During this process, there are two types of vapor condensation on the wall: one is film condensation. When the condensate wets the wall, a continuous liquid film is formed on the wall; the vapor condenses on the surface of the liquid film. The latent heat released by condensation must pass through this liquid film to be transmitted to the wall, so the liquid film is the thermal resistance of condensation heat transfer. The other is droplet condensation. If the condensate does not wet the wall, the condensate adheres to the wall in the form of droplets. When the droplets grow to a certain size, they roll off or drip along the wall surface to expose the wall without droplets for continued condensation. The exothermic coefficient at the time of droplet condensation is more than 5 times larger than that in the case of film condensation. In practical equipment, the droplet condensation is unstable, usually in the form of membrane condensation, so the condensation heat transfer equipment is generally designed in the form of a membrane condensation. During the condensation heat transfer process, by applying an electric field to the fluid, the nucleation radius of the droplets can be reduced, the condensate film can be thinned, and even the film condensation can be converted into quasi-drop condensation. During the boiling heat transfer process and the condensation heat transfer process, the convection caused by the electric field force can also disturb the gas-liquid interface, thereby accelerating heat exchange. It can be seen from the above that in the boiling heat exchange process, the heat transfer coefficient and the critical heat flux density of the gas-liquid phase change process can be enhanced by applying an electric field to the fluid.

3 is a schematic view showing the operation of a flat heat pipe in the prior art. As shown in FIG. 3, the flat heat pipe of the prior art comprises a housing 301 and a wick 302 fixed on the inner surface of the housing 301. The wick 302 is a capillary structure, and the inside of the housing 301 is a vacuum chamber. The working medium is provided, and the working medium is located on the surface inside the casing and the surface of the heat absorbing core. The flat heat pipe shown in FIG. 3 is divided into an evaporation section 31, an adiabatic section 32, and a condensation section 33. The specific solution for dissipating heat from the flat heat pipe is to attach the chip to the outer surface of the casing of the evaporation section 31. When the heat generated by the chip is conducted to the evaporation section 31, the liquid working medium inside the casing starts to boil in a low vacuum environment. The phase change produces a vapor, and then the vapor condenses in the condensation section 33 to dissipate the heat, and the liquid working medium produced by the condensation returns to the evaporation section 31 due to the capillary adsorption of the wick. Wherein, the adiabatic section 32 can increase the temperature difference between the evaporation section 31 and the condensation section 33, thereby achieving a better heat dissipation effect of the flat heat pipe.

In the prior art, the flat heat pipe has the following disadvantages: when the calorific value of the chip is too large, excessive bubbles are generated in the evaporation section in the flat heat pipe, and the gas film is formed due to the bubble not being quickly separated from the heat exchange surface, thereby increasing the thermal resistance and forming a "boiling". crisis". At the same time, the liquid working medium condensed in the condensation section adheres to the condensation surface to hinder the condensation of other bubbles, so that the liquid working medium cannot be quickly returned to the evaporation section, so that the heat transfer coefficient of the flat heat pipe is greatly reduced, resulting in the risk of burning the chip.

4(a)-(d) are schematic structural views of a flat heat pipe provided by an embodiment of the present application. As shown in FIG. 4, the flat heat pipe provided by the embodiment of the present application includes a casing 44, a wick 43 and a working medium. The casing 44 and the wick 43 are made of a metal material, the wick 43 and an appropriate amount of working medium. Placed inside the housing 44, the interior of the housing is a vacuum chamber. The wick 43 is fixed to the inner surface of the casing 44, and an insulating material 42 is disposed between the wick 43 and the inner surface of the casing 44. The wick 43 is connected to the first potential, the housing 44 is connected to the second potential, and the first potential has a potential difference from the second potential. It should be noted that the flat heat pipe can be divided into an evaporation section and a condensation section as needed, or a heat insulation section can be disposed between the evaporation section and the condensation section. As shown in FIG. 4(b), the heat insulating portion 442 can be realized by sheathing the rubber sleeve 47 on the outer surface of the segment housing 44, so that the flat plate heat pipe has no heat exchange with the outside. By setting the adiabatic section, the temperature difference between the evaporation section and the condensation section can be increased, so that the flat heat pipe can achieve a better heat dissipation effect.

Illustratively, the second potential can be zero potential. It should be noted that after the external cavity of the flat heat pipe is connected to the zero potential, it is a good shielding cover, which can prevent the electric field introduced in the heat dissipation system from interfering with the electronic components outside the heat dissipation system. at this time, The housing of the flat heat pipe can be insulated.

Illustratively, the first potential is constant and the second potential is adjustable. Alternatively, the second potential is constant and the first potential is adjustable. Alternatively, the first potential and the second potential are unchanged. Alternatively, both the first potential and the second potential are adjustable.

For example, the first potential is adjustable and the second potential is unchanged. By adjusting the input voltage on the electrode of the first potential, the magnitude of the electric field force can be changed, and the heat transfer coefficient can be adjusted to adjust the temperature of the evaporation section of the flat heat pipe to achieve the effect of active temperature control.

Illustratively, as shown in Figure 4b, the wick 43 can be connected to the first potential through the first lead 45. A lead hole is disposed in the housing 44, and the first lead 45 penetrates the lead hole, and the lead hole and the first lead 45 are sealingly connected.

The first lead 45 is an insulated shielded wire. The first lead 45 is insulatively connected to the lead hole to maintain insulation between the first lead 45 and the housing 44 that is connected to the second potential to avoid short circuit. The insulated shielding wire is a conductor wrapped around the conductor. The wrapped conductor is called a shielding layer. Generally, it is a braided copper mesh or copper foil (or aluminum mesh or copper foil). The shielding layer needs to be grounded. The external interference signal can be used by this layer. Import the earth. At the same time, since the connection between the first lead 45 and the lead hole may have electromagnetic overflow, the filter capacitor 46 may also be connected in the first lead 45, thereby eliminating and shielding the electromagnetic generated due to the internal high potential change of the flat heat pipe. interference.

Alternatively, as shown in FIG. 4(c), the wick 43 may be provided with an external wire 48 instead of the first lead 45 shown in FIG. 4(b). The wick 43 is connected to the first potential by an external wire 48. A wire hole is disposed in the housing 44, and the external wire 48 extends through the wire hole, and the wire hole and the external wire 48 are sealingly connected. For example, the wick 43 may be provided with an external wire in a welded form, and the wire hole and the external wire are sealedly connected, and the outer surface of the external wire is coated with an insulating varnish or an insulating glue and insulated from the wire hole. .

Illustratively, the housing 44 is connected to the second potential through the second lead 41.

It should be noted that the surface of the wick 43 , the first lead 45 or the external wire 48 is covered with an insulating material to ensure that the wick 43 , the first lead 45 , the external wire 48 and the housing 44 are insulated from each other. Short circuit, while the wick 43 and the first lead 45 or the external wire 48 are in communication. At this time, the internal current of the wick 43, the first lead 45, and the external wire 48 can be ignored.

Illustratively, the surface of the housing 44 is covered with an insulating material.

The manner of covering the insulating material may be, for example, spraying an insulating varnish or an insulating glue on the surface of the wick 43, the first lead 45, the circumscribed wire 48 or the casing 44.

Illustratively, the insulating material 42 is a strip of glue. For example, the wick 43 is fixed to the inner surface of the flat heat pipe with a strip. For another example, after the insulating varnish is sprayed on the surface of the wick 43, the wick 43 is fixed to the inner surface of the flat heat pipe with a strip.

Illustratively, the wick 43 is a capillary structure formed of a single layer or a plurality of layers of wire mesh. For example, as shown in FIG. 4(d), the wick 43 is a single-layer wire mesh composed of a wire (solid) 431 having a diameter d of less than 1 mm. It should be noted that when the wick is in a capillary structure, after the liquid working medium adheres to the wick, it will flow back to the evaporation section under the action of capillary force (including falling on the shell corresponding to the evaporation section). The inner surface, or still attached to the wick of the evaporation section, is again involved in the boiling phase transition process.

Illustratively, the working medium is a heat exchange medium such as water and a refrigerant. For example, the working medium is water, Freon or trichlorotrifluoroethane R113.

Illustratively, the material of the housing and the wick is copper, aluminum or stainless steel. For example, the housing 44 may be made of stainless steel and the wick 43 may be made of copper.

Illustratively, the wick 43 is connected to a high potential voltage, and the housing 44 of the flat heat pipe is connected to zero potential, thereby forming no A uniform electric field.

The heat dissipation process of the chip can be performed by using the flat heat pipe provided by the embodiment of the present application. The heat dissipation process can be: attaching the chip to the outer surface of the casing 44 corresponding to the evaporation section 441, and the heat generated by the chip is transmitted to the evaporation section of the flat heat pipe. 441. The working medium inside the flat heat pipe boils and absorbs heat in the heat exchange surface of the evaporation section 441 (ie, the inner surface of the casing corresponding to the evaporation section), and becomes a bubble. At this time, the electric field accelerates the detachment of the bubble, and the working fluid boils. The gas flows to the condensation section 443, condenses in the cold, becomes a liquid, releases heat, and the electric field accelerates the condensation of the gas at this time, and the liquid produced by the condensation flows back to the evaporation section through the wick, and participates in the foregoing process again. By adjusting the input voltage on the high potential electrode, the heat transfer coefficient can be adjusted to adjust the temperature of the evaporation section, thereby achieving the effect of active temperature control.

The flat heat pipe provided by the embodiment of the present invention can strengthen the characteristics of the convective heat transfer process by using an electric field, and the liquid absorbing core and the shell are used as electrodes, and an electric field is introduced to enhance heat dissipation, and the heat transfer coefficient and the critical heat flow density of the flat heat pipe are increased to make the heat dissipation. More powerful, applied to the terminal electronic equipment, can effectively reduce the temperature rise of the device and the whole machine. At the same time, by adjusting the electric field strength, active control of the temperature of the flat heat pipe can be achieved. Insulation and access filtering devices for flat heat pipes can avoid short circuits and eliminate electromagnetic interference. Grounding the metal case can obtain a good electromagnetic shielding effect, thereby effectively improving the thermal reliability and thermal experience of the flat heat pipe.

FIG. 5 is a schematic structural view of a microchannel in the prior art. Microchannels are also known as microchannel heat exchangers. As shown in Figure 5, there are dozens of fine flow channels in the microchannel heat exchanger. Connected to the circular header at both ends of the microchannel. A partition is provided in the header to divide the heat exchanger flow path into several processes. Microchannel heat exchangers can be divided into micro microchannel heat exchangers and large scale microchannel heat exchangers according to their size. The micro microchannel heat exchangers are available in polymethyl methacrylate, nickel, copper, stainless steel, ceramic, silicon, Si ₃ N ₄ and aluminum. Large-scale microchannel heat exchangers form microchannel large-scale production technology mainly by extrusion technology, limited by pressure processing technology, and the materials available are also very limited, mainly aluminum and aluminum alloy.

FIG. 6 is a schematic structural diagram of a microchannel heat dissipation system according to an embodiment of the present application. As shown in FIG. 6 , the microchannel heat dissipation system provided by the embodiment of the present application includes a working medium, a circulation pipe 605, a micro pump 606, and a condenser 607, and a bottom plate 612. The inner surface of the bottom plate 612 is a heat exchange surface, and The bottom plate 612 is oppositely disposed with a top plate 611. The two ends of the top plate 611 are respectively provided with an inlet 604 and an outlet 608. The inlet 604 and the outlet 608 are connected by a circulation pipe 605. The circulation pipe 605 is also connected with a micro pump 606 and a condenser 607. . The edges of the top plate 611 and the bottom plate 612 are surrounded by an insulating side plate 601, and the space surrounded by the top plate 611, the bottom plate 612 and the insulating side plate 601 is a microchannel. The top plate 611 and the bottom plate 612 are made of a metal material, the top plate 611 is connected to the first potential, and the bottom plate 612 is connected to the second potential, wherein the first potential and the second potential have a potential difference.

Illustratively, the bottom plate 612 is coupled to the shield 603, the shield 603 is made of a metallic material, and the bottom plate 612 is coupled to the second potential through the shield 603.

Illustratively, the shield is connected to the second potential through the second lead 602.

Illustratively, the shield 603 is a wire mesh.

Illustratively, the second potential is zero potential. It should be noted that after the bottom plate 612 and the shield cover 603 are connected to the zero potential, the shielding effect is good, and the electric field introduced in the heat dissipation system can be prevented from interfering with the electronic components outside the heat dissipation system. At this time, the surfaces of the bottom plate 612 and the shield case 603 may not be subjected to insulation treatment. It should be noted that the bottom plate 612 and the shield cover 603 are both made of a metal material, and have a shielding effect after being connected to a zero potential, regardless of whether the surface is insulated or not.

Illustratively, the first potential is constant and the second potential is adjustable. Alternatively, the second potential is constant and the first potential is adjustable. Alternatively, the first potential and the second potential are unchanged. Alternatively, both the first potential and the second potential are adjustable. For example, the first potential is adjustable and the second potential is unchanged. The electric field force can be changed by adjusting the input voltage on the electrode of the first potential The size can be adjusted to adjust the heat transfer coefficient to adjust the temperature of the heat transfer surface to achieve the effect of active temperature control.

Illustratively, the top plate 611 is connected to the first potential through the first lead 609. A filter capacitor 610 is inserted in the first lead 609, and the filter capacitor 610 is used to eliminate and shield electromagnetic interference that may occur due to internal high potential changes of the microchannel heat dissipation system.

Illustratively, the first lead 609 is an insulated shielded wire. It should be noted that the first lead 609 is insulated and shielded from the shield 603 to avoid short circuit. At the same time, there may be electromagnetic spillage at the junction of the first lead 609 and the top plate 611.

Illustratively, the microchannel heat exchange surface 613 is a profiled wall. For example, the cross section of the microchannel heat exchange surface 613 is triangular zigzag or rectangular zigzag or the like.

Exemplarily, the material of the insulating side plate 601 is an insulating material such as polyimide.

Illustratively, the top plate 611 and the first lead 609 are covered with an insulating material. For example, the surfaces of the top plate 611 and the first lead 609 are sprayed with an insulating varnish or an insulating glue to avoid a short circuit. For another example, the inner and outer surfaces of the top plate 611 are sprayed with an insulating varnish, and the surface of the first lead 609 is coated with an insulating glue. At this time, the internal current of the wick and the first lead 609 can be ignored.

Illustratively, the material of the circulation duct 605 is rubber.

Illustratively, the metallic material is copper, aluminum or stainless steel. For example, the material of the microchannel heat exchange surface 613, the bottom plate 612, and the metal wall surface may be copper, aluminum, or stainless steel.

Illustratively, the top plate 611 is connected to a high potential and the bottom plate 612 is connected to a zero potential to form a non-uniform electric field between the top plate 611 and the microchannel heat exchange surface 613. The heat dissipation process of the microchannel heat dissipation system provided by the embodiment of the present application may be: placing the chip on the outer surface of the bottom plate 612, the heat generated by the chip is transmitted to the microchannel heat exchange surface, and the working medium flowing in the micro channel In the heat exchange surface of the microchannel, the heat is boiled and becomes a bubble. At this time, the electric field accelerates the detachment of the bubble. By adjusting the input voltage on the high potential electrode, the heat transfer coefficient can be adjusted, thereby adjusting the temperature of the heat exchange surface of the microchannel. Thereby achieving the effect of active temperature control. The gas-liquid two-phase fluid produced by the boiling of the working fluid flows to the condenser through the pump, and condenses in the cold, becomes a liquid, releases heat, and then flows from the micro pump to the microchannel.

The microchannel heat dissipation system provided by the embodiment of the present invention utilizes an electric field energy to enhance the characteristics of the boiling and forced convection heat exchange process, and uses the heat exchange surface of the top plate and the microchannel as an electrode to introduce an electric field to enhance heat dissipation, and improve heat transfer of the microchannel heat dissipation system. The coefficient and critical heat flux density make the heat dissipation capability more powerful, and can be applied to the terminal electronic equipment, which can effectively reduce the temperature rise of the device and the whole machine. At the same time, by adjusting the electric field strength, active control of the temperature of the microchannel heat exchange surface can be achieved. The microchannel heat exchange surface is designed as a profiled wall surface, which can effectively increase the heat exchange area. The top plate is insulated and connected to the filtering device to avoid short circuits and eliminate electromagnetic interference. By grounding the shield and the bottom plate, a good electromagnetic shielding effect can be obtained, thereby effectively improving the thermal reliability and thermal experience of the microchannel heat dissipation system.

The flat heat pipe and the micro channel heat dissipation system provided by the embodiments of the present application can be applied to a terminal (such as a notebook computer or a tablet computer). When the terminal includes a flat heat pipe or a micro channel heat dissipation system, the flat heat pipe or the micro channel heat dissipation system can adopt the present application. The structure provided by any of the embodiments.

The specific embodiments of the present invention have been described in detail with reference to the specific embodiments of the present application. It is to be understood that the foregoing description is only The scope of protection, any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this application are intended to be included within the scope of the present application.

Claims

A flat heat pipe comprising a casing, a wick and a working medium, the casing and the wick being made of a metal material, the wick and the working medium being placed inside the casing; It is characterized in that

The wick is fixed to an inner surface of the casing, and a first insulating material is disposed between the wick and an inner surface of the casing;

The wick is connected to the first potential;

The housing is connected to a second potential, and the first potential has a potential difference from the second potential.
The flat heat pipe according to claim 1, wherein

The wick is connected to the first potential through a first lead;

A lead hole is disposed on the housing, the first lead penetrates the lead hole, and the lead hole is sealingly connected to the first lead.
The flat heat pipe according to claim 2, wherein a filter capacitor is inserted into the first lead, and the filter capacitor is used to eliminate electromagnetic interference.
A flat heat pipe according to any one of claims 1 to 3, wherein the second potential is a zero potential.
A flat heat pipe according to any one of claims 1 to 3, characterized in that

The first potential is unchanged and the second potential is adjustable; or

The second potential is unchanged and the first potential is adjustable; or

The first potential and the second potential are unchanged; or

The second potential and the second potential are both adjustable.
The flat heat pipe according to claim 1, wherein said wick and said first lead surface are covered with a second insulating material.
The flat heat pipe according to claim 1, wherein said first lead wire is an insulated shield wire.
The flat heat pipe according to claim 1, wherein the first insulating material is a strip.
The flat heat pipe according to claim 1, wherein the wick is a capillary structure formed of a single layer or a plurality of layers of wire mesh.
The flat heat pipe according to claim 1, wherein the working medium is water or a refrigerant.
The flat heat pipe according to claim 1, wherein the metal material is copper, aluminum or stainless steel.
A microchannel heat dissipation system comprising a working medium, a circulation pipe, a micro pump and a condenser, wherein

The bottom plate is disposed opposite to the bottom plate, and the top plate is provided with an inlet and an outlet respectively, and the inlet and the outlet are connected by a circulation pipe, and the circulation pipe is also connected with a micro pump and condensation Device

The top plate and the edge of the bottom plate are enclosed with an insulating side plate, and the top plate, the bottom plate and the insulating side plate surround the microchannel;

The top plate and the bottom plate are made of a metal material, the top plate is connected to a first potential, the bottom plate is connected to a second potential, and the first potential has a potential difference from the second potential.
The microchannel heat dissipation system according to claim 11, wherein said bottom plate and said shield cover Connected, the shield is made of a metal material, and the bottom plate is connected to the second potential through the shield.
The microchannel heat dissipation system according to claim 13, wherein the shield is a wire mesh.
The microchannel heat dissipation system according to claim 12, wherein

The top board is connected to the first potential through a first lead;

A filter capacitor is inserted into the first lead, and the filter capacitor is used to eliminate electromagnetic interference.
The microchannel heat dissipation system of claim 15 wherein said first lead is an insulated shield.
A microchannel heat dissipation system according to any one of claims 12-16, wherein the second potential is zero potential.
A microchannel heat dissipation system according to any one of claims 12-16, wherein

The first potential is unchanged and the second potential is adjustable; or

The second potential is unchanged and the first potential is adjustable; or

The first potential and the second potential are unchanged; or

The second potential and the second potential are both adjustable.
The microchannel heat dissipation system according to claim 12, wherein the inner surface of the bottom plate is a heat exchange surface, and the heat exchange surface is triangular zigzag.
The microchannel heat dissipation system according to claim 12, wherein the material of the insulating side plate is polyimide.
The microchannel heat dissipation system according to claim 12, wherein said top plate and said first lead surface are covered with an insulating material.
The microchannel heat dissipation system according to claim 12, wherein the material of the circulation duct is rubber.
The microchannel heat dissipation system according to claim 12, wherein the working medium is water or a refrigerant.
The microchannel heat dissipation system according to claim 12, wherein the metal material is copper, aluminum or stainless steel.
A terminal, characterized in that the terminal comprises a flat heat pipe according to any one of claims 1 to 11 or a microchannel heat dissipation system according to any one of claims 12 to 24.