Heat energy driven loop heat pipe pump-free circulation chip heat dissipation device and method

Abstract

The invention discloses a heat energy-driven loop heat pipe pump-free circulation chip heat dissipation device and a heat energy-driven loop heat pipe pump-free circulation chip heat dissipation method. The device comprises a condenser, a first micro-channel etched on the bottom surface of a chip substrate, a manifold etched on the upper surface of a ceramic base at the cold end of the TEC, a manifold micro-channel bonded by the manifold and the first micro-channel, and a second micro-channel etched on the lower surface of a ceramic base at the hot end of the TEC, and capillary core structures are arranged in the first micro-channel and the second micro-channel. The liquid heat dissipation working medium flows through the manifold micro-channels and evaporates on the outer surface of the capillary core of the first micro-channel, the generated capillary pressure difference provides primary capillary force drive for circulation, the heat dissipation working medium enters the second micro-channel to absorb heat released by the TEC hot end and evaporates on the outer surface of the capillary core, and the heat dissipation working medium absorbs the heat released by the TEC hot end. Capillary pressure difference is formed to provide secondary capillary force driving for working medium circulation; an inlet and an outlet of the condenser are connected with the second micro-channel and the manifold micro-channel correspondingly, working media in the heat dissipation system are driven to circulate through capillary force, and the problem of poor reliability caused by pump failure is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of chip heat dissipation, and in particular to a heat-energy driven loop heat pipe pumpless circulation chip heat dissipation device and method. Background Art

[0002] With the increase of chip power consumption and integration, the chip heat dissipation problem has become a key challenge in the development of modern electronic technology. The heat dissipation problem of the chip is not only related to its performance stability, but also directly affects the service life and reliability of the equipment. The traditional air cooling method is no longer sufficient for modern high-power chips, which has prompted the development and application of emerging heat dissipation technologies such as microchannel liquid cooling, thermoelectric cooling, and loop heat pipe cooling.

[0003] In liquid cooling technology, indirect liquid cooling has greater scale advantages due to its wide range of material selection and small impact on equipment structure, and has gradually been widely used in the heat dissipation of high-power electronic devices. However, analysis of the liquid cooling system found that the system requires a mechanical pump to drive the liquid circulation to complete the heat dissipation, which is prone to the problem of difficult to ensure the heat dissipation effect due to pump instability or even failure. For example: during long-term operation, the mechanical parts of the pump may wear due to friction, resulting in a decrease in the efficiency of the pump, or even complete failure of the pump; as the use time increases, the pump seal may age or be damaged, causing coolant leakage or air to enter the pump, thereby affecting the cooling efficiency, and in severe cases, the pump may stop working. Summary of the invention

[0004] The purpose of the present invention is to provide a heat energy driven loop heat pipe pumpless circulation chip cooling device and method, which can avoid the problem of affecting the chip cooling effect due to the poor reliability of the mechanical pump in the existing liquid cooling system.

[0005] The technical solution of the present invention is: A heat-driven loop heat pipe pumpless circulating chip cooling device, wherein a first microchannel is etched on the bottom surface of a chip substrate for mounting a chip, a capillary wick structure is arranged in the first microchannel, and a TEC heat dissipation module is configured under the chip substrate, wherein the TEC heat dissipation module comprises: a TEC cold end, a manifold is etched on the upper surface of the ceramic substrate of the TEC cold end, the manifold is bonded to the first microchannel to form a manifold microchannel, the manifold is used to reasonably distribute the liquid flow entering each microchannel to ensure uniform and efficient heat dissipation effect, the liquid heat dissipation medium is heated when flowing through the manifold microchannel to dissipate heat for the chip, evaporates on the outer surface of the capillary wick of the first microchannel, and the capillary pressure difference generated inside the capillary wick is the heat dissipation in the first microchannel loop. The circulation of the heat medium provides a primary capillary force drive; the TEC hot end, the ceramic substrate lower surface of the TEC hot end is etched with a second microchannel, and a capillary wick structure is arranged therein, and the heat dissipating medium flows out of the manifold microchannel and enters the second microchannel to absorb the heat released by the TEC hot end, so that the liquid medium in the capillary wick absorbs the heat and evaporates on the outer surface of the capillary wick to form a gaseous heat dissipating medium. The capillary pressure difference formed inside the capillary wick provides a secondary capillary force drive for the circulation of the heat dissipating medium in the second microchannel loop; the condenser, the inlet end is connected to the second microchannel, which is used to convert the gaseous heat dissipating medium into a liquid heat dissipating medium, and the outlet end is connected to the manifold microchannel, which is used to transport the liquid heat dissipating medium. The capillary driving force provided by the capillary wick in the microchannel must be greater than or equal to the flow pressure drop in the entire loop. The capillary force attracts the liquid in the condenser into the manifold microchannel.

[0006] Furthermore, the second microchannel includes: a groove and a cover plate, the groove is etched on the lower surface of the ceramic base at the hot end of the TEC, and the cover plate is arranged on the lower surface of the ceramic base at the hot end of the TEC.

[0007] Furthermore, the chip substrate is one of a silicon-based substrate Si, a silicon carbide substrate SiC, a gallium oxide substrate Ga2O3 or a sapphire substrate Al2O3.

[0008] Furthermore, the capillary wick structure is made of porous materials, such as metal powder, wire mesh or foamed metal, which are sintered through a specific process to form a structure with tiny pores. The pore size determines the size of the capillary driving force in the loop. The smaller the pore size, the greater the capillary driving force. The specific size of the capillary structure needs to match the loop system.

[0009] Furthermore, the manifold is a Z-shaped manifold, which ensures that the fluid can be evenly distributed to each microchannel and reduces the flow resistance of the fluid in the microchannel.

[0010] Furthermore, a liquid storage tank is included, which is arranged between the condenser and the manifold microchannel, and is used to store the converted liquid heat dissipation medium and transport it to the TEC cold end. The existence of the liquid storage tank can adjust and stabilize the circulation flow of the heat dissipation medium, and can temporarily store a part of the heat dissipation medium to cope with the supply demand fluctuation caused by the change of heat load.

[0011] Furthermore, both the second microchannel and the first microchannel have a wavy structure.

[0012] Furthermore, a method for cooling a chip by a heat-driven loop heat pipe pumpless circulating chip cooling device comprises the following steps: The liquid heat sink flowing out of the condenser flows through the liquid storage tank and then enters the manifold microchannel formed by the microchannel at the bottom of the chip substrate and the manifold bonded to the upper surface of the ceramic substrate at the cold end of the TEC. The liquid heat sink in the manifold microchannel absorbs the heat emitted by the chip to dissipate the heat for the chip. The liquid heat sink in the microchannel capillary core structure is heated and evaporates on the outer surface of the capillary core. The capillary pressure difference generated inside the capillary core provides a primary capillary force drive for the circulation of the heat sink in the loop. At the same time, the coldness provided by the TEC cold end to the manifold microchannel not only improves the heat dissipation capacity of the heat sink in the manifold microchannel, but also causes the bubbles generated in the flow channel to burst and reduce their volume, which not only helps to avoid channel blockage, but also helps to reduce flow resistance.

[0013] After the heat dissipation medium flows out of the manifold microchannel, it enters the microchannel at the lower end of the ceramic base of the TEC hot end to absorb the heat released by the TEC hot end, so that the liquid medium in the capillary core absorbs the heat and evaporates on the outer surface of the capillary core. At this time, the capillary pressure difference formed inside the capillary core provides a secondary capillary force drive for the heat dissipation medium circulation in the loop. After the heat dissipation medium flows out of the microchannel, it enters the condenser, where the gaseous heat dissipation medium is transformed into liquid and flows into the liquid storage tank to complete the cycle.

[0014] The present invention adopts a capillary structure as a power driving device, and utilizes a "capillary pump" instead of a "mechanical pump" to drive the working medium circulation in the heat dissipation system.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention makes full use of the operating characteristics of TEC, which can absorb heat at the cold end and release heat at the hot end. The capillary pressure difference formed inside the manifold microchannel and the capillary wick structure arranged in the microchannel is used to provide capillary force drive for the circulation of the heat dissipating medium in the loop, so as to achieve the effect of circulation without a pump structure. The capillary wick structure arranged in the microchannel provides capillary force drive for the circulation of the heat dissipating medium. The liquid heat dissipating medium flowing out of the condenser flows through the liquid reservoir and enters the manifold microchannel to absorb the heat dissipated by the chip. When heated, it evaporates on the outer surface of the capillary wick. The capillary pressure difference generated inside the capillary wick provides a first-level capillary force drive for the circulation of the heat dissipating medium in the loop. At the same time, the cold amount provided by the cold end of the TEC to the manifold microchannel, on the one hand, improves the heat dissipation capacity of the heat dissipating medium in the manifold microchannel, and on the other hand, it will make the heat generated in the flow channel The bubbles burst and their volume becomes smaller, which not only helps to avoid channel blockage, but also helps to reduce flow resistance; after the heat dissipation medium flows out of the manifold microchannel, it enters the second microchannel to absorb the heat released by the hot end of the TEC, so that the liquid medium in the capillary core absorbs heat and evaporates on the outer surface of the capillary core. At this time, the capillary pressure difference formed inside the capillary core provides a secondary capillary force drive for the circulation of the heat dissipation medium in the loop, and provides a capillary force drive for the circulation of the heat dissipation medium in the loop to achieve the effect of circulation without a pump structure, avoiding the problem of unstable driving force of the mechanical pump on the heat dissipation medium caused by wear of parts and aging of seals after long-term use of the mechanical pump in the traditional heat dissipation device driven by the mechanical pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the main structure of the present invention.

[0017] Figure 2 It is a schematic diagram of the chip and its chip substrate structure of the present invention.

[0018] Figure 3 It is a schematic diagram of the structure of the TEC heat dissipation module of the present invention.

[0019] Figure 4 It is a schematic diagram of the manifold structure of the present invention.

[0020] Figure 5 It is a scanning electron microscope image of the capillary core structure of the present invention.

[0021] Figure 6 Schematic diagram of the second microchannel structure in Example 2.

[0022] Figure 7 This is a schematic diagram of the first microchannel structure in Example 2.

[0023] Among them, 1. chip, 2. chip substrate, 3. TEC cold end, 4. TEC hot end, 5. condenser, 6. first microchannel, 7. second microchannel, 8. manifold, 9. liquid storage tank. DETAILED DESCRIPTION

[0024] The following is combined with Figure 1 To the attached Figure 7 , the specific embodiments of the present invention are described in detail. In the description of the present invention, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0025] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features; in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0026] Example 1 like Figure 1 and Figure 2 As shown, a heat-driven loop heat pipe pumpless circulating chip cooling device, a first microchannel 6 is etched on the bottom surface of a chip substrate 2 for mounting a chip 1, a capillary wick structure is arranged in the first microchannel 6, and a TEC heat dissipation module is configured below the chip substrate 2, the TEC heat dissipation module comprises: a TEC cold end 3, a TEC hot end 4 and a condenser 5, a manifold 8 is etched on the upper surface of the ceramic substrate of the TEC cold end 3, the manifold 8 is bonded to the first microchannel 6 to form a manifold microchannel, the manifold 8 is used to reasonably distribute the liquid flow entering each microchannel to ensure a uniform and efficient heat dissipation effect, the liquid heat dissipation medium is heated when flowing through the manifold microchannel to dissipate heat for the chip 1, evaporates on the outer surface of the capillary wick of the first microchannel 6, and the capillary pressure difference generated inside the capillary wick provides a primary capillary force drive for the heat dissipation medium circulation in the loop of the first microchannel 6; as shown Figure 3 and Figure 4As shown, the second microchannel 7 is etched on the lower surface of the ceramic substrate of the TEC hot end 4, and a capillary core structure is arranged therein. After the heat dissipation medium flows out of the manifold microchannel, it enters the second microchannel 7 to absorb the heat released by the TEC hot end 4, so that the liquid medium in the capillary core absorbs the heat and evaporates on the outer surface of the capillary core to form a gaseous heat dissipation medium. The capillary pressure difference formed inside the capillary core provides a secondary capillary force drive for the circulation of the heat dissipation medium in the second microchannel 7 loop; the inlet end of the condenser 5 is connected to the second microchannel 7 for converting the gaseous heat dissipation medium into a liquid heat dissipation medium, and the outlet end is connected to the manifold microchannel for conveying the liquid heat dissipation medium. It is worth noting that the capillary core structure is arranged in both the first microchannel 6 and the second microchannel 7, and the combined force of the capillary driving force generated in the two microchannels must be greater than or equal to the flow pressure drop in the entire circulation loop, and the capillary driving force attracts the liquid in the condenser 5 into the manifold microchannel. The flow pressure drop includes the momentum pressure drop, gravity pressure drop and friction pressure drop caused by the flow of heat dissipation medium in pipes or other flow systems.

[0027] The energy input of the heat dissipation device comes from the heat dissipation of the chip 1 on the one hand, and from the working current input at both ends of the TEC heat dissipation module on the other hand. The capillary pressure difference formed inside the capillary core provides capillary force drive for the circulation of the heat dissipation medium in the loop.

[0028] like Figure 3 As shown, the second microchannel 7 includes: a groove and a cover plate, the groove is etched on the lower surface of the ceramic base of the TEC hot end 4, and the cover plate is covered on the lower surface of the ceramic base of the TEC hot end 4.

[0029] The chip substrate 2 is one of a silicon-based substrate Si, a silicon carbide substrate SiC, a gallium oxide substrate Ga2O3 or a sapphire substrate Al2O3. The present embodiment adopts a silicon-based substrate Si.

[0030] like Figure 5 As shown in the figure, the capillary wick structure is made of porous materials, such as metal powder, wire mesh or foam metal, which are sintered through a specific process to form a structure with tiny pores. The pore size determines the size of the capillary driving force in the loop. The smaller the pore size, the greater the capillary driving force. The specific size of the capillary structure needs to match the loop system.

[0031] In some embodiments, Figure 4 As shown, the manifold 8 is a Z-shaped manifold, which ensures that the fluid can be evenly distributed to each microchannel and reduces the flow resistance of the fluid in the microchannel.

[0032] In some embodiments, a liquid storage tank 9 is further included, which is disposed between the condenser 5 and the manifold microchannel, and is used to store the converted liquid heat dissipation medium and transport it to the TEC cold end 3. The existence of the liquid storage tank 9 can adjust and stabilize the circulation flow of the heat dissipation medium, and can temporarily store a part of the heat dissipation medium to cope with the supply demand fluctuation caused by the change of heat load.

[0033] The method for cooling a chip using the above-mentioned heat energy driven loop heat pipe pumpless circulation chip cooling device comprises the following steps: The liquid heat dissipating medium flowing out of the condenser 5 flows through the liquid storage tank 9 and then enters the manifold microchannel bonded by the microchannel at the bottom of the chip substrate 2 and the manifold 8 on the upper surface of the ceramic base of the TEC cold end 3. The liquid heat dissipating medium in the manifold microchannel absorbs the heat emitted by the chip 1 to dissipate heat for the chip 1. The liquid heat dissipating medium in the microchannel capillary core structure is heated and evaporates on the outer surface of the capillary core. The capillary pressure difference generated inside the capillary core provides a primary capillary force drive for the circulation of the heat dissipating medium in the loop. At the same time, the coldness provided by the TEC cold end 3 to the manifold microchannel, on the one hand, improves the heat dissipation capacity of the heat dissipating medium in the manifold microchannel, and on the other hand, causes the bubbles generated in the flow channel to burst and reduce the volume, which is not only conducive to avoiding channel blockage, but also helps to reduce flow resistance.

[0034] After the heat dissipation medium flows out of the manifold microchannel, it enters the microchannel at the lower end of the ceramic base of the TEC hot end 4 to absorb the heat released by the TEC hot end 4, so that the liquid medium in the capillary core absorbs the heat and evaporates on the outer surface of the capillary core. At this time, the capillary pressure difference formed inside the capillary core provides a secondary capillary force drive for the heat dissipation medium circulation in the loop. After the heat dissipation medium flows out of the microchannel, it enters the condenser 5, where the gaseous heat dissipation medium is transformed into liquid and flows into the liquid storage tank 9 to complete the cycle.

[0035] In this embodiment, the heat dissipation medium is divided into each microchannel through the rectangular first microchannel 6 and the rectangular second microchannel 7, so that the circulation driving force required by the heat dissipation medium is evenly distributed in each microchannel, and the capillary pressure difference generated in the microchannel provides the driving force for the heat dissipation medium, thereby ensuring the stable circulation of the heat dissipation medium in the circulation pipeline. Specifically, the heat dissipation medium is first evenly distributed to each first microchannel 6 of the rectangular structure through the bonding between the manifold 8 and the first microchannel 6, so that the liquid heat dissipation medium divided into each microchannel can receive the heat emitted by the chip 1 more evenly and comprehensively, and evaporate more efficiently on the outer surface of the capillary core when heated, and the capillary pressure difference generated inside the capillary core provides a primary capillary force drive for the circulation of the heat dissipation medium in the loop. Similarly, the heat dissipation medium flows through the microchannel at the lower end of the ceramic base of the TEC hot end 4 to absorb the heat released by the TEC hot end 4, so that the liquid medium in the capillary core absorbs the heat and evaporates on the outer surface of the capillary core, and the capillary pressure difference formed inside the capillary core provides a secondary capillary force drive for the circulation of the heat dissipation medium in the loop.

[0036] Example 2 like Figure 6 and Figure 7 As shown, the second microchannel 7 and the first microchannel 6 both adopt a wavy structure. The microchannel with a wavy structure can increase the effective contact area between the fluid (heat dissipating medium) in the microchannel and the microchannel, thereby improving the efficiency of heat transfer.

[0037] When the fluid passes through the microchannel with a wavy structure, the disturbance of the fluid (heat dissipation medium) in the microchannel is enhanced, thereby inhibiting the full development of the boundary layer along the flow direction, further improving the heat exchange effect, and further ensuring the generation of capillary force in the microchannel, ensuring the continuous circulation of the heat dissipation medium in each microchannel.

[0038] The above disclosures are only several preferred specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A heat-driven loop heat pipe pumpless circulating chip cooling device, characterized in that: A first microchannel (6) is etched on the bottom surface of a chip substrate (2) for mounting a chip (1), a capillary wick structure is arranged in the first microchannel (6), and a TEC heat dissipation module is configured below the chip substrate (2), the TEC heat dissipation module comprising: A TEC cold end (3), a manifold (8) is etched on the upper surface of the ceramic substrate of the TEC cold end (3), the manifold (8) is bonded to the first microchannel (6) to form a manifold microchannel, the manifold (8) is used to reasonably distribute the liquid flow entering each microchannel, the liquid heat sink flows through the manifold microchannel to dissipate heat for the chip (1), and is heated and evaporates on the outer surface of the capillary core of the first microchannel (6), and the capillary pressure difference generated inside the capillary core provides a primary capillary force drive for the circulation of the heat sink in the loop of the first microchannel (6); A TEC hot end (4), wherein a second microchannel (7) is etched on the lower surface of the ceramic substrate of the TEC hot end (4), and a capillary wick structure is arranged therein, and after the heat dissipation medium flows out of the manifold microchannel, it enters the second microchannel (7) to absorb the heat released by the TEC hot end (4), so that the liquid medium in the capillary wick absorbs the heat and evaporates on the outer surface of the capillary wick to form a gaseous heat dissipation medium, and the capillary pressure difference formed inside the capillary wick provides a secondary capillary force drive for the circulation of the heat dissipation medium in the loop of the second microchannel (7); The condenser (5) has an inlet end connected to the second microchannel (7) for converting gaseous heat dissipation medium into liquid heat dissipation medium, and an outlet end connected to the manifold microchannel for conveying the liquid heat dissipation medium.

2. The heat-driven loop heat pipe pumpless circulating chip cooling device according to claim 1, characterized in that: The second microchannel (7) comprises: a groove and a cover plate, the groove being etched on the lower surface of the ceramic base at the TEC hot end (4), and the cover plate being arranged to cover the lower surface of the ceramic base at the TEC hot end (4).

3. The heat-driven loop heat pipe pumpless circulating chip cooling device according to claim 1, characterized in that: The chip substrate (2) is one of a silicon-based substrate Si, a silicon carbide substrate SiC, a gallium oxide substrate Ga2O3 or a sapphire substrate Al2O3.

4. The heat-driven loop heat pipe pumpless circulating chip cooling device according to claim 1, characterized in that: The capillary wick structure is made of a porous material.

5. The heat-driven loop heat pipe pumpless circulating chip cooling device according to claim 1, characterized in that: The manifold (8) is a Z-shaped manifold.

6. The heat energy driven loop heat pipe pumpless circulating chip cooling device according to claim 1, characterized in that: It also includes a liquid storage tank (9), which is arranged between the condenser (5) and the manifold microchannel and is used to store the converted liquid heat dissipation medium and transport it to the TEC cold end (3).

7. The heat energy driven loop heat pipe pumpless circulating chip cooling device according to claim 1, characterized in that: The second microchannel (7) and the first microchannel (6) both have a wavy structure.

8. The method for cooling a chip by using a heat-driven loop heat pipe pumpless circulating chip cooling device according to claim 1, characterized in that: The following steps are involved: The liquid heat dissipating medium flowing out of the condenser (5) enters the manifold microchannel formed by bonding the microchannel at the bottom of the chip substrate (2) and the manifold (8) on the upper surface of the ceramic substrate of the TEC cold end (3). The liquid heat dissipating medium in the manifold microchannel absorbs the heat emitted by the chip (1) to dissipate heat for the chip (1). The liquid heat dissipating medium in the capillary wick structure in the first microchannel (6) is heated and evaporates on the outer surface of the capillary wick. The capillary pressure difference generated inside the capillary wick provides a primary capillary force drive for the circulation of the heat dissipating medium in the loop. At the same time, the TEC cold end (3) provides cooling for the manifold microchannel. After the heat dissipation medium flows out of the manifold microchannel, it enters the second microchannel (7) to absorb the heat released by the TEC hot end (4), causing the liquid medium in the capillary core to absorb the heat and evaporate on the outer surface of the capillary core. At this time, the capillary pressure difference formed inside the capillary core provides a secondary capillary force drive for the heat dissipation medium circulation in the loop. After the heat dissipation medium flows out of the microchannel, it enters the condenser (5). In the condenser (5), the gaseous heat dissipation medium is converted into liquid and flows back into the manifold microchannel to complete the cycle.

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