A transient thermal buffer device based on electrohydrodynamic driving phase change material

Abstract

The application relates to a transient heat buffering device driven by a phase change material based on electrohydrodynamics, and belongs to the technical field of electronic device heat management and cooling.The application aims to solve the problem that, in the existing heat buffering mode of phase change material for electronic device heat dissipation, a stagnant molten layer is formed at a hot end after the phase change material is melted, the unmelted phase change material is hindered from continuously contacting a heat source exchange surface, and the latent heat utilization rate is reduced; an electrode assembly is installed on an EHD pumping module with a micro-pump channel; a phase change material module assembly is arranged on the EHD pumping module with the micro-pump channel; a cover body with a sealing layer is arranged on the phase change material module assembly and the EHD pumping module with the micro-pump channel; a medium material is arranged in the cover body with the sealing layer and the EHD pumping module with the micro-pump channel; and the electrode assembly drives the medium material to circulate in the cover body with the sealing layer and the EHD pumping module with the micro-pump channel.

Description

Technical Field

[0001] This invention relates to a transient thermal buffer device for driving phase change materials, specifically a transient thermal buffer device for driving phase change materials based on electrohydrodynamics. This invention belongs to the field of thermal management and cooling technology for electronic devices. Background Technology

[0002] With the development of power electronic devices, lasers, chip packaging modules, aerospace electronic equipment, and highly integrated power modules, devices are prone to generating large transient heat inputs in a short period of time during startup, pulse operation, load surges, peak power output, or the formation of local hot spots. This causes heat to accumulate rapidly in localized areas, resulting in a sharp rise in device temperature. If such transient thermal shocks cannot be buffered or transferred in time, it may lead to chip junction temperature exceeding limits, increased thermal stress in the package, fluctuations in device performance, and even a decrease in reliability.

[0003] While traditional air cooling, water cooling, or heat pipe cooling methods can achieve heat transfer under certain operating conditions, their response to sudden heat flow and short-term high heat loads is still limited by fluid inertia, heat transfer paths, system volume, and the arrangement of heat exchange structures. Especially in applications with limited space, low noise, hermetic encapsulation, or where mechanical pumps are inconvenient, traditional circulating cooling systems often suffer from problems such as large size, complex structure, limited response speed, noise and vibration, and high maintenance costs.

[0004] Phase change materials (PCMs) are widely used for thermal buffering and transient thermal management in electronic devices due to their ability to absorb or release large amounts of latent heat during phase transitions. Compared to materials that rely solely on sensible heat, PCMs can absorb a significant amount of heat within a relatively small temperature fluctuation range, effectively suppressing peak temperature rises from heat sources. However, existing PCM heat dissipation structures often employ fixed filling, encapsulation, or passive melting methods near the heat source. When the PCM near the heat exchange surface melts, a molten layer tends to form at the hot end. This molten layer typically has low thermal conductivity and limited fluidity, and it hinders the unmelted PCM from continuing contact with the heat exchange surface, resulting in slow phase change interface advancement, a gradual increase in the thermal resistance of the liquid layer, and a decrease in latent heat utilization.

[0005] To address these issues, existing technologies often employ passive enhancement methods such as metal foams, graphite sheets, microgrooves, fins, or heat pipes to improve the internal thermal conductivity of PCMs. However, these solutions primarily reduce heat transfer resistance by enhancing solid-state heat conduction paths or increasing heat exchange areas, failing to fundamentally solve the problems of liquid PCM molten layer retention on the heat source surface and the inability to actively renew the phase change interface. Traditional mechanical pump drives typically require moving parts such as impellers, pistons, and diaphragms, along with corresponding sealing structures, making it difficult to achieve stable and reliable fluid circulation in miniaturized, thin, and highly integrated packages. Furthermore, they suffer from noise and vibration, mechanical wear, risk of seal failure, and structural complexity, making them unsuitable for compact phase change material heat dissipation devices used in transient thermal buffering scenarios.

[0006] Electrohydrodynamics (EHD) pumping technology enables directional flow in dielectric or weakly conductive liquids through the action of an electric field. Its basic principle is that charge injection, conduction, or polarization near the electrodes induces an electric force in the liquid, thereby driving macroscopic flow. EHD pumping systems typically eliminate the need for impellers, pistons, or diaphragms, and are characterized by their compact structure, low noise, integrability, and voltage-regulated flow intensity, making them suitable for microscale fluid transport and thermal management.

[0007] Existing EHD pumping technologies mainly focus on single-phase transport of dielectric liquids, droplet manipulation, microfluidic drive, or conventional heat exchange enhancement. They have not yet proposed a complete closed-loop interface renewal scheme for how to continuously peel off, replenish, and regenerate the cold end of phase change materials after the formation of a molten retention layer at the hot end.

[0008] Therefore, this invention proposes a closed-loop heat dissipation system that can actively update the phase change interface at the heat exchange surface of the heat source by utilizing the EHD pumping effect, so that the molten PCM can leave the hot end region in time, and the low temperature, unmelted or semi-solid PCM can be continuously replenished to the hot end heat exchange surface, thereby reducing the thermal resistance of the liquid phase change layer, improving the latent heat utilization rate, and realizing miniaturized active heat dissipation without mechanical moving parts. Summary of the Invention

[0009] The purpose of this invention is to solve the problem that existing electronic devices use phase change materials for heat dissipation, which form a molten layer at the hot end after the phase change material melts, preventing the unmelted phase change material from continuing to contact the heat exchange surface of the heat source and reducing the latent heat utilization rate. Therefore, this invention provides a transient heat buffer device based on electrohydrodynamics driving phase change materials.

[0010] The technical solution adopted by the present invention to solve the above problems is as follows:

[0011] A transient thermal buffer device based on electrohydrodynamics-driven phase change material includes an EHD pumping module with micro-pump channels, an electrode assembly, a phase change material module assembly, and a cover with a sealing layer.

[0012] The electrode assembly is mounted on the EHD pumping module with micro-pump channels, the phase change material module assembly is set on the EHD pumping module with micro-pump channels, and the cover with a sealing layer is mounted on the phase change material module assembly and the EHD pumping module with micro-pump channels. The phase change material module assembly contains phase change material, and the cover with the sealing layer and the cavity of the EHD pumping module with micro-pump channels contain dielectric material. The electrode assembly drives the dielectric material to circulate within the cover with the sealing layer and the cavity of the EHD pumping module with micro-pump channels.

[0013] Furthermore, the EHD pumping module with micro-pump channels is positioned near the external heat source, while the cover with a sealing layer is positioned near the cold source.

[0014] Furthermore, the EHD pumping module with micro-pump channels includes a module substrate and a dielectric liquid. Multiple channels are machined side by side on the module substrate. Each channel has a flow channel inlet and a flow channel outlet at both ends. Electrode mounting slots are machined on both sides of each channel.

[0015] Furthermore, the electrode assembly includes a plurality of first polarity electrodes and a plurality of second polarity electrodes;

[0016] Each channel has a first polarity electrode in the electrode mounting slot on one side and a second polarity electrode in the electrode mounting slot on the other side. The first and second polarity electrodes drive the dielectric liquid to flow directionally within the channel.

[0017] Furthermore, the phase change material module assembly includes a phase change material containing module and a phase change material;

[0018] The phase change material receiving module is machined with a phase change material receiving tank, and multiple flow holes are machined on the bottom of the phase change material receiving tank. Flow channels are machined at both ends of the phase change material receiving module, and the phase change material is placed in the phase change material receiving tank.

[0019] Furthermore, the cover with the sealing layer includes the sealing layer and the cover;

[0020] The cover has grooves machined on it, and flow channels are machined at both ends of the grooves. The cover is sealed to the EHD pumping module and phase change material module assembly with micro-pump channels through a sealing layer to form a closed space.

[0021] Furthermore, it also includes a sieve.

[0022] A screen is installed on the phase change material module assembly to restrict the solid phase change material from entering the EHD pumping module with micro-pump channels. The screen allows the molten liquid phase change material to enter the EHD pumping module with micro-pump channels through the screen and flow holes.

[0023] Furthermore, the inlet and outlet of the flow channel on the module base are respectively set to correspond to the flow channels at both ends of the phase change material module assembly above, and the flow channels of the phase change material module assembly are respectively set to correspond to the flow grooves on the cover. A circulation flow channel is formed through the inlet, groove, outlet, flow channel, flow groove and recess.

[0024] Furthermore, the first polarity electrode is a positive electrode, and the second polarity electrode is a negative electrode.

[0025] After the positive and negative electrodes are energized, they drive the dielectric liquid to flow directionally in the circulation channel formed by the inlet, channel, outlet, flow hole, flow groove and recess, and the dielectric liquid drives the liquid phase change material to flow into the recess.

[0026] Furthermore, the EHD pumping module with micro-pump channels, the phase change material module assembly, and the cover with a sealing layer are fixedly connected by bolts to form a sealed structure.

[0027] Compared with the prior art, the present invention has the following technical advantages:

[0028] 1. The present invention adopts an integrated stacked structure, which integrates the EHD pumping module 1 with micro-pump channels at the bottom, the phase change material module component 3 in the middle, and the cover 5 with a sealing layer at the top into the same device. The structure is compact and the overall thickness can be controlled at the millimeter level. It is suitable for thermal management in space-constrained scenarios such as chips, power devices, laser devices and high heat flux density electronic devices.

[0029] 2. The present invention provides a slit-type partial connection structure between the phase change material module component 3 and the EHD pumping module 1 with micro-pump channel, so that the liquid phase change material formed by melting on the side near the heat source can enter the lower channel 12, while the solid phase change material body is still confined within the phase change material containment layer, thereby reducing the risk of solid phase change material directly entering the micro-pump channel and causing blockage.

[0030] 3. The present invention utilizes the action of an EHD pump to drive the dielectric liquid to flow directionally in the bottom channel 12, so that the liquid phase change material entering the channel 12 through the screen 4 is carried, dragged and transported away from the hot end region by the dielectric liquid, thereby reducing the long-term residence of the liquid phase change material near the heat source, reducing the additional thermal resistance brought by the hot end liquid phase change material layer, and improving the latent heat utilization efficiency of the phase change material.

[0031] 4. This invention features an integrated circulation loop within the device, allowing the liquid phase change material carried away from the hot end region by the dielectric liquid to return to the central phase change material module assembly 3 via lateral or end return channels. This structure avoids the complex connections of external long pipelines and independent cold end regeneration devices, thus improving the device's integration and operational reliability.

[0032] 5. Since the device of the present invention has a millimeter-level integrated stacked structure, the distance between the channel 12, the inlet 14 and the outlet 15 and the phase change material containing module 31 is short. The residence time of the liquid phase change material in the reflux channel is short, and it will not solidify in the reflux channel in advance, thereby reducing the risk of reflux blockage.

[0033] 6. The present invention provides a top cold source or cooling cover above the phase change material containing layer, so that the liquid phase change material flowing back into the phase change material containing module 31 can be cooled down and re-solidified under the action of the top cold source, thereby replenishing the solid phase change material in the phase change material containing layer and realizing the cycle process of "hot end melting - micro pump channel pumping - short-distance reflux - top re-solidification - phase change material replenishment".

[0034] 7. This invention enables phase change materials to no longer be used as passive heat storage media with fixed filling, but to be melted, pumped out, refluxed and resolidified inside the device, thereby improving the reusability and thermal buffering capacity of phase change materials.

[0035] 8. This invention uses EHD drive as the power source for dielectric liquid circulation, eliminating the need for moving parts such as mechanical pumps, impellers, pistons, or diaphragms. This reduces noise, vibration, mechanical wear, and the risk of seal failure, making it suitable for miniaturized, thinner, and enclosed electronic heat dissipation devices.

[0036] 9. This invention integrates the EHD micro-pump channel, electrode assembly, phase change material containment layer, reflux channel and top cold source into one unit, reducing the use of external pipelines, independent cold end modules and external circulation components, which helps to reduce system complexity, improve packaging reliability and enhance its application feasibility in the field of heat dissipation of electronic devices.

[0037] 10. The device of the present invention enables molten PCM to leave the hot end region in a timely manner and continuously replenishes low-temperature, unmelted or semi-solid PCM to the hot end heat exchange surface, thereby reducing the thermal resistance of the liquid phase change layer, improving the latent heat utilization rate, and realizing miniaturized active heat dissipation without mechanical moving parts.

[0038] 11. By combining phase change materials with dielectric properties with the structure of EHD pumping dielectric liquid, the latent heat absorption capacity of the phase change material is used to buffer the sudden heat under transient high heat load conditions, and the EHD pumping action is used to promote the transport, reflux and resolidification replenishment of molten phase change material inside the device.

[0039] 12. This invention enables the phase change material to be partially melted above the heat source and enter a micro-groove. Then, the dielectric liquid driven by EHD actively carries away the molten phase change material along the direction of the groove. The molten phase change material is cooled and solidified in the cold end regeneration module and separated from the dielectric liquid. The dielectric liquid returns to the hot end in a closed loop, thereby realizing the continuous renewal of the hot end molten layer, reducing the thermal resistance of the liquid phase change layer on the surface of the heat source, improving the latent heat utilization rate of the phase change material, and realizing miniaturized heat dissipation without mechanical moving parts. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0041] Figure 2 This is a schematic diagram of the structure of the present invention before assembly;

[0042] Figure 3 This is a schematic diagram of the structure of electrode assembly 2 mounted on EHD pumping module 1 with micro-pump channels;

[0043] Figure 4 This is a schematic diagram of the EHD pumping module 1 with micro-pump channels;

[0044] Figure 5 This is a schematic diagram of the structure of phase change material module component 3;

[0045] Figure 6 This is a schematic diagram of the structure of the groove 52 and flow channel 51 machined on the cover;

[0046] Figure 7 This is a schematic diagram of a liquid phase change material and a dielectric liquid circulation channel. Detailed Implementation

[0047] Combination Figure 1 and Figure 2 This embodiment describes a transient thermal buffer device for phase change materials driven by electrohydrodynamics, which includes an EHD pumping module 1 with micropump channels, an electrode assembly 2, a phase change material module assembly 3, and a cover 5 with a sealing layer.

[0048] Electrode assembly 2 is mounted on EHD pumping module 1 with micro-pump channels, phase change material module assembly 3 is mounted on EHD pumping module 1 with micro-pump channels, and cover 5 with sealing layer is mounted on phase change material module assembly 3 and EHD pumping module 1 with micro-pump channels. Phase change material is provided inside phase change material module assembly 3, and medium material is provided inside cover 5 with sealing layer and EHD pumping module 1 with micro-pump channels. Electrode assembly 2 drives the medium material to circulate in cover 5 with sealing layer and EHD pumping module 1 with micro-pump channels.

[0049] The EHD pumping module 1 with micro-pump channels is located at the bottom layer of the overall device. In this embodiment, the EHD pumping module 1 with micro-pump channels is filled with a dielectric material, and an electrode assembly 2 for generating an electric field is installed on the EHD pumping module 1 with micro-pump channels. Under the action of the electric field of electrohydrodynamics, the dielectric material flows directionally along the micro-pump channels; and it exerts a carrying or dragging effect on the liquid phase change material entering the EHD pumping module 1 with micro-pump channels, causing the liquid phase change material to be carried away from the hot end region. At the same time, some phase change materials in the phase change material module assembly 3, such as paraffin-based phase change materials, also have certain dielectric properties after melting into a liquid state. Therefore, when a sudden change in heat flow occurs from an external heat source, the phase change material located on the side of the phase change material module assembly 3 closer to the heat source first absorbs heat and melts, forming a liquid phase change material. The liquid phase change material is transported away from the adjacent heat source area by the entrainment and dragging effect of the medium material in the EHD pumping module 1 with micro-pump channel and the effect of the EHD electric field. This reduces the retention of the liquid phase change material at the hot end and reduces the risk of temperature rise caused by rapid local heat accumulation.

[0050] Combination Figure 1 As shown, the EHD pumping module 1 with micro-pump channels is positioned near an external heat source, while the cover 5 with a sealing layer is positioned near a cold source.

[0051] Combination Figure 3 and Figure 4 As shown, the EHD pumping module 1 with micro-pump channels includes a module substrate 11 and a dielectric liquid. Multiple channels 12 are machined side by side on the module substrate 11. Each channel 12 has a flow channel inlet 14 and a flow channel outlet 15 machined at both ends. Each channel 12 has an electrode mounting groove 13 machined on both sides.

[0052] In this embodiment, the dielectric liquid is one of the materials in the EHD pumping module 1 electrode assembly 2 with micro-pump channel that drives the medium material to flow in the channel 12.

[0053] Combination Figure 2 and Figure 3 As shown, the electrode assembly 2 includes a plurality of first polarity electrodes 21 and a plurality of second polarity electrodes 22;

[0054] Each channel 12 has a first polar electrode 21 in an electrode mounting groove 13 on one side and a second polar electrode 22 in an electrode mounting groove 13 on the other side. The first polar electrode 21 and the second polar electrode 22 drive the dielectric liquid to flow directionally within the channel 12.

[0055] In this embodiment, both the first polarity electrode 21 and the second polarity electrode 22 are made of brass. The electrodes are preferably embedded, with their working surfaces flush or substantially flush with the sidewall surface of the channel 12, and do not protrude into the main channel. The electrodes are preferably made of copper and manufactured using CNC machining.

[0056] Combination Figure 2 and Figure 6 As shown, the phase change material module assembly 3 includes a phase change material containing module 31 and a phase change material;

[0057] The phase change material receiving module 31 is machined with a phase change material receiving tank, and multiple flow holes are machined on the bottom of the phase change material receiving tank. Flow channels 32 are machined at both ends of the phase change material receiving module 31, and the phase change material is placed in the phase change material receiving tank.

[0058] In this embodiment, the phase change material containing module 31 is disposed above the channel 12 and is used to contain solid phase change materials such as solid, semi-solid, sheet-like, and block-like materials. When the heat source is working, the side of the phase change material closest to the microchannel opening melts first to form a liquid state. After the liquid phase change material is carried away from the hot end by the dielectric liquid driven by EHD in the channel 12, the unmelted or lower-temperature phase change material above continues to sink, contact or approach the microchannel opening area, thereby forming a new molten interface. The phase change material containing module 31 is made of acrylic material and is manufactured by laser cutting.

[0059] Combination Figure 2 and Figure 6 As shown, the cover 5 with the sealing layer includes a sealing layer and a cover body;

[0060] The cover has a groove 52 machined on it, and flow grooves 51 are machined at both ends of the groove 52. The cover is sealed with the EHD pumping module 1 with micro-pump channel and the phase change material module assembly 3 through the sealing layer to form a closed space.

[0061] In this embodiment, the cover 5 with a sealing layer is used to encapsulate the PCM, restrict its position, improve the overall sealing performance of the structure, and form an integrated stacked structure together with the EHD pumping module 1 with micro-pump channels at the bottom and the housing layer of the phase change material module assembly 3. The groove 52 and flow channel 51 on the cover are used to form a circulation loop together with the flow hole, flow channel inlet 14, flow channel outlet 15 and channel 12 inlet and outlet of the phase change material housing tank for pumping the mixture of dielectric liquid and liquid PCM. The groove 52 and flow channel 51 on the cover of the phase change material housing tank of the phase change material housing module 31 are used to receive the mixed fluid of dielectric liquid and molten liquid phase change material discharged from the hot end, and under the action of the cold source, the molten liquid phase change material releases latent heat, cools down and undergoes solidification phase change. After the mixed fluid enters the groove 52 and flow channel 51 on the cover of the phase change material receiving tank of the cold-end phase change material receiving module 31, the liquid phase change material solidifies into a solid or semi-solid phase change material under cooling, while the dielectric liquid remains in a liquid flow state within this temperature range, thus achieving solid-liquid separation. The solidified phase change material is trapped and deposited in the phase change material receiving module, while the dielectric liquid flows out through the outlet channel and returns to the hot-end opening micro-channel to participate in the circulation. At the same time, the dielectric liquid carrying heat releases heat on the solid or semi-solid phase change material as it flows, causing it to form a liquid phase change material and participate in the thermal cycle again.

[0062] Combination Figure 2 and Figure 7 As shown, it also includes a screen 4.

[0063] The screen 4 is installed on the phase change material module assembly 3 to restrict the solid phase change material from entering the EHD pumping module 1 with micro-pump channels. The screen 4 allows the molten liquid phase change material to enter the EHD pumping module 1 with micro-pump channels through the screen 4 and the flow holes.

[0064] In this embodiment, after the liquid phase change material enters the pump channel, it is dispersed in the dielectric liquid in the form of droplets or fine streams. Under the combined influence of the entrainment, dragging and transport of the dielectric liquid and the effect of the EHD electric field, it leaves the adjacent heat source area and goes to the downstream area.

[0065] Combination Figures 2 to 7 As shown, the inlet 14 and outlet 15 of the flow channel on the module base 11 are respectively set to correspond to the flow channels 32 at both ends of the phase change material module assembly 3 above. The flow channels 32 of the phase change material module assembly 3 are respectively set to correspond to the flow grooves 51 on the cover. A circulation flow channel is formed by the inlet 14, the channel 12, the outlet 15, the flow channel 32, the flow grooves 51 and the recesses 52.

[0066] Combination Figure 2 , Figure 3 , Figure 5 and Figure 7As shown, the first polarity electrode 21 is the positive electrode, and the second polarity electrode 22 is the negative electrode.

[0067] After the positive and negative electrodes are connected to the power supply, the dielectric liquid is driven to flow directionally in the circulation channel formed by the inlet 14, channel 12, outlet 15, flow channel 32, flow groove 51 and groove 52, and the dielectric liquid drives the liquid phase change material to flow into the groove 52.

[0068] In this embodiment, the molten liquid phase change material can return to the phase change material receiving module 31 via the dielectric liquid through the internal circulation channel of the device. There, it is cooled and re-solidified by the top cold source or top cooling structure, thereby replenishing the solid phase change material in the phase change material receiving layer. Thus, the process of "melting and heat absorption – EHD transport – internal reflux – top re-solidification – circulation replenishment" of the phase change material can be realized within the integrated package, avoiding unidirectional consumption of the phase change material, improving the reusability of the phase change material, and enhancing the device's continuous buffering capacity against transient heat flow shocks.

[0069] Combination Figure 1 As shown, the EHD pumping module 1 with micro-pump channels, the phase change material module assembly 3, and the cover 5 with a sealing layer are fixedly connected by bolts to form a sealed structure.

[0070] Example

[0071] This embodiment adopts a three-layer stacked structure. The overall dimensions of the device are approximately 60 mm × 24 mm × 3 mm, including, from bottom to top, an EHD pumping module 1 with micro-pump channels, an intermediate phase change material module assembly 3, a cover 5 with a sealing layer, and a top cover / cold source contact layer.

[0072] The bottom layer, the EHD pumping module 1 with micro-pump channels, has external dimensions of approximately 60 mm × 24 mm × 1 mm. It is made of thermally conductive and electrically insulating alumina ceramic material, and the EHD micro-pump channels 12 are formed by laser processing. This layer has a total of 10 parallel micro-grooves to form flow channels for the dielectric liquid, with micro-grooves measuring 50 mm × 0.8 mm × 0.6 mm. Each channel 12 contains electrode mounting slots 13 corresponding to the positive and negative electrode assemblies.

[0073] The electrode mounting slots 13 are used to install the electrode assembly 2, allowing the electrode assembly 2 to be embedded in the channel 12 and in contact with the dielectric liquid. The electrode mounting slots 13 can be arranged at intervals along the length of the channel 12 to form staggered electrode mounting positions, so as to generate a non-uniform electric field in the microchannel and drive the dielectric liquid to flow in a directional manner.

[0074] The electrode mounting slot is connected to the positive electrode lead-out channel and the negative electrode lead-out channel, so that the electrode assembly can be led out from the side or end of the device and connected to an external high-voltage drive power supply.

[0075] The intermediate phase change material containing module 31 and the liquid phase selective entry layer have external dimensions of approximately 60 mm × 24 mm × 1.05 mm. This layer is used to contain solid or semi-solid phase change materials and can accommodate materials with dimensions of 38 mm × 222 mm × 1 mm. A micro-groove or partially interconnected structure is provided on one side near the bottom channel 12, allowing the liquid phase change material formed under the action of a heat source to enter the lower channel 12, while the solid phase change material body is confined within the phase change material containing area.

[0076] The top cover / cold source contact layer has external dimensions of approximately 60 mm × 24 mm × 1 mm. This layer is used to encapsulate the phase change material containing layer and can also serve as the contact interface for the top cold source or cooling structure, allowing the liquid phase change material flowing back into the phase change material containing module 31 to be cooled and solidified again under the action of the top cold source, thereby replenishing the solid phase change material in the phase change material containing module 31.

[0077] In other embodiments, the electrode assembly 2 includes an upper electrode plate and a lower electrode plate, both measuring approximately 50 mm × 0.40 mm × 0.55 mm. The upper and lower electrode plates are connected to positive and negative terminals, respectively, both measuring approximately 0.60 mm × 20.50 mm × 0.40 mm. The electrodes can be made of brass, copper, nickel, gold-plated metal, or other conductive materials.

[0078] Sealing gaskets can be installed between the EHD pumping module 1 with micro-pump channels, the phase change material module assembly 3, and the cover 5 with a sealing layer to ensure that the dielectric liquid and liquid phase change material do not leak during circulation within the device. The shorter distance between the EHD pumping module 1 with micro-pump channels, the phase change material module assembly 3, and the cover 5 with a sealing layer results in a shorter residence time of the liquid phase change material in the reflux channel, making it less prone to premature solidification and reducing the risk of reflux blockage.

[0079] The phase change material can be a paraffin-based phase change material, the dielectric liquid can be HFE-7100, the EHD electrode can be made of brass, the microgroove and channel support structure is preferably made of an electrically insulating and thermally conductive ceramic material, and the top cover can be made of transparent acrylic material to observe the melting, pumping, reflux and resolidification process of the phase change material.

[0080] This device may not directly include a heat source and a cold source. The heat source can be an electronic device, chip, power module, laser device, power supply module, or other heat-generating component to be cooled. The heat source is thermally coupled to the underlying EHD micropump channel layer through a thermally conductive substrate, thermally conductive adhesive, solder layer, metal heat diffusion plate, or other thermally conductive connection methods. The cold source can be an external cooling structure located above or thermally connected to the top cover, including but not limited to a cold plate, heat sink, coolant channel, air-cooled structure, semiconductor refrigeration chip, metal cooling block, or ambient cooling end. The cold source is used to reduce the temperature of the top region of the phase change material containment layer, allowing the liquid phase change material flowing back into the phase change material containment layer to cool down and re-solidify, thereby replenishing the solid phase change material.

Claims

1. A transient thermal buffer device based on electrohydrodynamics-driven phase change material, characterized in that... It includes an EHD pumping module (1) with micro-pump channels, an electrode assembly (2), a phase change material module assembly (3), and a cover with a sealing layer (5). Electrode assembly (2) is mounted on EHD pumping module (1) with micro-pump channel, phase change material module assembly (3) is set on EHD pumping module (1) with micro-pump channel, cover (5) with sealing layer is sealed on phase change material module assembly (3) and EHD pumping module (1) with micro-pump channel, phase change material is provided in phase change material module assembly (3), medium material is provided in cover (5) with sealing layer and EHD pumping module (1) with micro-pump channel, and electrode assembly (2) drives medium material to circulate in cover (5) with sealing layer and EHD pumping module (1) with micro-pump channel.

2. The transient thermal buffer device based on electrohydrodynamics-driven phase change material according to claim 1, characterized in that... The EHD pumping module (1) with micro-pump channel is located near an external heat source, and the cover (5) with a sealing layer is located near a cold source.

3. The transient thermal buffer device based on electrohydrodynamics-driven phase change material according to claim 1, characterized in that... The EHD pumping module (1) with micro pump channels includes a module substrate (11) and a dielectric liquid. Multiple channels (12) are machined side by side on the module substrate (11). Each channel (12) has a flow channel inlet (14) and a flow channel outlet (15) at both ends. Each channel (12) has an electrode mounting groove (13) on both sides.

4. The transient thermal buffer device based on electrohydrodynamics-driven phase change material according to claim 1, characterized in that... The electrode assembly (2) includes a plurality of first polarity electrodes (21) and a plurality of second polarity electrodes (22). Each channel (12) has a first polar electrode (21) in an electrode mounting groove (13) on one side and a second polar electrode (22) in an electrode mounting groove (13) on the other side. The dielectric liquid is driven to flow in a direction within the channel (12) by the first polar electrode (21) and the second polar electrode (22).

5. The transient thermal buffer device based on electrohydrodynamics-driven phase change material according to claim 1, characterized in that... The phase change material module assembly (3) includes a phase change material containing module (31) and a phase change material; The phase change material receiving module (31) is machined with a phase change material receiving tank. Multiple flow holes are machined on the bottom of the phase change material receiving tank. Flow channels (32) are machined at both ends of the phase change material receiving module (31). The phase change material is placed in the phase change material receiving tank.

6. The transient thermal buffer device based on electrohydrodynamics-driven phase change material according to claim 1, characterized in that... :The cover with a sealing layer (5) includes the sealing layer and the cover; The cover has a groove (52) machined on it, and flow grooves (51) are machined at both ends of the groove (52). The cover is sealed with the EHD pumping module (1) with micro pump channel and the phase change material module assembly (3) through the sealing layer to form a closed space.

7. The transient thermal buffer device based on electrohydrodynamics-driven phase change material according to claim 1, characterized in that... It also includes a sieve (4). A screen (4) is set on the phase change material module assembly (3) to restrict the solid phase change material from entering the EHD pumping module (1) with micro-pump channels. The screen (4) allows the molten liquid phase change material to enter the EHD pumping module (1) with micro-pump channels through the screen (4) and the flow holes.

8. The transient thermal buffer device based on electrohydrodynamics-driven phase change material according to claim 1, characterized in that... The inlet (14) and outlet (15) of the flow channel on the module base (11) are respectively set to correspond to the flow channels (32) at both ends of the phase change material module assembly (3) above. The flow channels (32) of the phase change material module assembly (3) are respectively set to correspond to the flow groove (51) on the cover. A circulation flow channel is formed through the inlet (14), the channel (12), the outlet (15), the flow channel (32), the flow groove (51) and the groove (52).

9. The transient thermal buffer device based on electrohydrodynamics-driven phase change material according to claim 1, characterized in that... The first polarity electrode (21) is the positive electrode, and the second polarity electrode (22) is the negative electrode. After the positive and negative electrodes are connected to the power supply, the dielectric liquid is driven to flow in a directional manner in the flow channel inlet (14), channel (12), flow channel outlet (15), flow channel (32), flow groove (51) and groove (52), and the dielectric liquid drives the liquid phase change material to flow into the groove (52).

10. The transient thermal buffer device based on electrohydrodynamics-driven phase change material according to claim 1, characterized in that... The EHD pumping module (1) with micro-pump channel, the phase change material module assembly (3) and the cover with sealing layer (5) are fixedly connected by bolts to form a sealed structure.

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