Water-cooled Heat Sink Research Articles

Fin angles optimization of water-cooled plate-fin heat sink based on anisotropic Darcy–Forchheimer theory

Flat heat sinks are devices for efficient heat dissipation and are important components in manufacturing. For example, in precision glass molding, it is utilized as a cooling plate contributing to improve the quality of the product by reducing residual stress and shape deviation, during the gradual cooling phase. In this study, we attempted to achieve precise temperature design of the cooling plate using variable lattice optimization. Fins allow for controlling the flow direction and achieving efficient heat transfer. Therefore, elliptical cylindrical fins were adopted as lattice unit cells, increasing the design freedom of the flow field. To account for the asymmetric flow field within the unit cell, we introduced an asymmetric tensor for the coefficients of the effective physical properties in the Darcy–Forchheimer equation. The proposed method's effectiveness and validity are discussed through numerical calculations with effective material properties, reproduced detailed shapes, and experimental verification. The optimization aiming to minimize the average temperature yielded a numerical simulation temperature decrease of 24.6 % and an experimental temperature decrease of 14.1 % compared to the benchmark model.

Evaluation of innovative thermal performance augmentation techniques in heat sinks & heat pipes: Electronics & renewable energy applications

Heat sinks and heat pipes have vast applications including industrial domains requiring high heat flux. Due to numerous uses of these heat transfer devices, there have been great advancement in this area through innovation. This study focuses use of nanofluids and hybrid nanofluids for thermal performance enhancement of heat pipes and heat sinks. There are five different arrangements finless sintered copper wicked heat pipe, water based TiO2 filled heat pipe, TiO2 and SiO2 based hybrid nanofluid filled heat pipe, water cooled cylindrical pin finned heat sink and Fe2O3 and TiO2 hybrid nanofluid cooled heat sink. There are two test rigs one for testing heat pipe configurations and other for heat sinks. All the five elements are tested at constant heat flux ranging from 900 W/m2 to 3600 W/m2, in four equal steps. It’s observed that nanofluids play a very significant role in thermal performance augmentation, the affect is even more significant in heat pipes compared to heat sinks. Interestingly, nanofluids based heat pipes are proved more significant for high heat flux applications, although, nanofluid cooled heat sinks have slight better performance compared to the said but at a higher expense of weight, auxiliaries, space and cost. At 3600 W/m2 nanofluid based heat pipes have 33 % lower thermal resistance compared to water cooled heat sink. Therefore, nanofluid based heat pipes are primarily significant unless use of heat sink deemed dire. Nusselt number of heat sink is calculated at various heat flux and at variable mass flux conditions and found increasing with both parameter.

Solar-powered thermoelectric refrigeration with integrated phase change material: An experimental approach to food storage

In this paper, a novel phase change material (PCM) based Thermoelectric (TE) food storage refrigerator incorporating an integrated solar-powered energy source is introduced. The novelty aspects of this research lie in the unique combination of PCM with solar energy, not only to maintain temperatures below 5 °C, vital for reducing food spoilage, but also in designing extra experiments using water as a cooling method to enhance system performance. Designed to preserve a diverse range of fruits and vegetables with different moisture content below 5 °C, the system innovatively employs PCM to extend cooling time, reduce energy load, and avoid conventional refrigerants, contributing to environmental sustainability. Experimentally, the average time for PCM solidification was around 3.5 h, with a corresponding latent heat release time, maintaining a temperature range of 0 to 5 °C. The system effectively accommodated various food items with water content levels from 50 % to 99 %, achieving the target temperature within around 2 to 4 h and demonstrating a promising coefficient of performance (COP) of 0.69. A standout innovation included the utilization of water flow through copper piping to accelerate heat removal from TEC, enhancing the performance of the system and reducing the solidification time of PCM by approximately an hour. This research represents a significant advancement in refrigeration technology, highlighting the feasibility and optimization potential of integrating solar energy and PCM, and introduces a new direction for enhancing efficiency through water-cooled heat sinks.

Efficient thermal management of high-power electronics via jet-enhanced HU-type manifold microchannel

To efficiently remove the increasingly higher heat fluxes from electronic chips, this numerical study presents an embedded single-phase water-cooled heat sink which consists of a microchannel layer and a jet-enhanced HU-type manifold layer. The manifold features two liquid inlet plenums symmetrically positioned on two opposite sides and some outlets arranged in the middle. In order to reduce the average thermal resistance, the fluid impinging velocity is boosted by narrowing the manifold channel inlet. However, narrower inlet also leads to flow maldistribution which increases the maximum thermal resistance. To address this problem, we demonstrate two approaches: either adding a flat plate at the manifold outlet or adjusting the manifold channel walls to form a tapered pathway. Further, the impact of the plenum and manifold channel inlet profiles on fluid flow and heat transfer is investigated. Negligible difference is found between rectangular and trapezoidal plenums. As to the manifold channel inlet, although similar heat transfer performance is obtained with different shapes, the total pressure drop can be substantially different. To reduce the large pressure drop at the inlet, a semicircular or triangular inlet profile is preferred, instead of a rectangular one. Quantitatively, we show that for a 3 × 3 mm2 heated area, our heat sink can dissipate fluxes up to 2000 W cm−2 with a maximum temperature rise of 65 K and a pressure drop below 40 kPa, which represents one of the highest performances and energy efficiencies reported to date.

Multi-objective reduced-order design optimization of single-phase liquid coolers for electronics

Thermal management using liquid cooled cold plates is a key enabler in modern electronic systems such as power converters and multi-chip arrays. Traditional cold plate designs are limited in their ability to handle the heterogeneous heat profiles in ever-larger modern multi-chip arrays requiring design optimization. This work demonstrates a design optimization method for liquid-cooled cold plates subjected to discrete heat dissipation profiles. We used reduced order performance modeling enabled by splitting the heat sink geometry onto a coarse grid with up to 50 elements each assigned with a simplified flow block such as a straight, elbow, or tee section. Correlations for thermal-fluidic performance metrics were used to obtain the pressure drop and surface temperature. Multi-objective design optimization focused on minimizing the pressure drop and temperature was broken down into layout and geometry optimization sub-steps. Layout optimization found the optimal flow path from inlet to outlet using a novel optimal path search method combining pathfinding algorithms with search on a random population. Geometry optimization solved for the dimensions of the coarse grid elements and the corresponding flow blocks using gradient based optimizers. We experimentally tested an aluminum water-cooled heat sink design generated by the reduced order optimization demonstrating a thermal resistance of 0.065 K/W. We compared the performance of our optimal designs with conventional and topology optimized cold plate designs to benchmark performance, computational cost, and computational time. Topology optimized designs showed a 22% reduction in average heated surface temperature for similar pressure drops. However, the computation time required to generate the topology optimized design was more than one order of magnitude higher than the reduced order method, requiring over 3,600 s to generate the optimal design. Our reduced order optimization in comparison provides optimal designs at computational timescales of 60 s.

On the flow field and heat transfer characteristics of a supercritical CO2-cooled microchannel heat sink under high heat flux conditions

Supercritical CO2 (sCO2) is a suitable choice as a coolant due to its favorable thermodynamic characteristics (lower density and viscosity, and higher specific heat) compared to water. In the current investigation, sCO2 is considered a coolant in a micro heat sink under high heat fluxes 75, 100, 125, and 150 W/cm2 and the operating pressure 8 MPa. The effects of the operating conditions, including the change in coolant mass flux (1250–3125 kg/s-m2), the change in the inlet temperature (305-308 K) under the mentioned heat fluxes on the heat transfer coefficient, thermal resistance, pressure drop, pumping power, and performance evaluation criteria (PEC) are investigated numerically using the finite volume method. Results indicated that thermohydraulic performance of the sCO2-cooled heat sink depends on the inlet coolant temperature and the applied heat flux due to the dramatic variation of the local thermophysical properties. It was found that increase in the heat flux from 75 to 150 W/cm2 results in increase of the pumping power by 48%, diminishing the PEC from 2.35 to 0.5. Overall, sCO2-cooled heat sink performs better than water-cooled heat sink if the mass flow rate is high and the inlet temperature is below the pseudocritical temperature. Otherwise, using sCO2 is not beneficial, especially under higher heat flux conditions.

Heat Transfer Performance of Water-cooled Heat Sink for I&C System Controller Chip in Nuclear Power Plant

To improve the heat dissipation reliability of the nuclear power control system chip, the structure of its water-cooled heat sink is compared and analyzed. Three schemes of water-cooled heat sinks are proposed, and CFD analyzes the heat dissipation performance of the heat sink. The simulation data of the heat transfer coefficient, pressure loss, and heat sink comprehensive coefficient are compared. The results show that the average temperature of the bottom surface of the three heat sinks tends to be flat with the flow velocity increase, and the heat dissipation coefficient Nu is also the same. The S-type heat sink has a higher heat transfer coefficient and lower average bottom temperature. The pressure loss of the S-type heat sink is much higher than that of the other two schemes with the increased flow rate, and the system resistance is large. By calculating the comprehensive coefficient of the heat dissipation process of the three heat sinks and considering the heat dissipation capacity and other factors, it is considered that the circular fin heat sink can be the optimal solution.

Material Plasma Exposure eXperiment High Heat Flux Microwave Absorber Design, Manufacture, and Articles Test

The Material Plasma Exposure eXperiment (MPEX) at Oak Ridge National Laboratory is in the final design phase. MPEX will be capable of exposing neutron-irradiated materials to plasmas for the study of plasma-material interaction. This facility will provide information about the complex effects of plasmas on materials and contribute to examining new materials that can withstand high heat fluxes and high ion fluences for future fusion devices. MPEX plasma is heated by 70-GHz or 105-GHz electron Bernstein wave/electron cyclotron heating (ECH), and the high-frequency microwaves are prone to scattering microwave power, which can have detrimental effects, especially on diagnostic components. A large portion of the injected ECH power is expected to be absorbed by plasma, but the remainder requires that microwave absorbers be placed immediately upstream and downstream of the ECH launcher to minimize stray microwaves leaving the ECH region. These microwaves can inadvertently heat components that cannot be shielded or otherwise protected. The microwave absorber design is based on an array of pyramid-shaped ceramic tiles brazed to a water-cooled explosion-bonded heat sink and a stainless steel plate to produce one tile module. Computational fluid dynamics and structural analyses were performed to optimize and validate the design. Multiple test coupons were produced to validate the process for brazing the two different tile materials to the Glidcop AL-15 baseplate. The articles were tested to evaluate the reliability and thermal performance through exposure to an electron beam with a heat flux of up to 1.5 MW/m2. Nondestructive testing was performed before and after testing to identify voids or separations that may have been introduced by the high heat flux. This paper discusses the details of high heat flux microwave absorber design, manufacturing details and associated challenges, and test results, demonstrating the effectiveness of the proposed design.

Topologically optimized mini-channel heat sinks for reduced temperature non-uniformity

Water-cooled mini-channel heat sinks are widely used for thermal management of electronic devices, but their flow paths are usually limited to simple designs, such as parallel channels, due to manufacturing limitations. Such designs do not distribute flow uniformly, resulting in non-uniform heat transfer across the heat sink and significant temperature gradients. A liquid-cooled heat sink with a millimeter high flow channel was designed and fabricated to cool an 86 mm x 63 mm uniformly distributed heat load. A density-based topology optimization model was implemented in COMSOL to generate a non-traditional internal geometry that minimizes temperature non-uniformity. The topologically optimized heat sink was made using a novel thermal spray additive manufacturing method in which molten aluminum was sprayed into a cavity machined in an aluminum plate through a polymer mask made in the shape of the desired flow channels by 3D printing. The cavity was closed with an aluminum plate to create a sealed heat sink. The thermal performance of the topologically optimized heat sink was compared experimentally to that of a heat sink with parallel channels. Each heat sink was placed on a uniformly heated copper block dissipating 180 – 630 W (corresponding to heat fluxes of 3.3 – 11.6 W/cm2) and its temperature measured by an array of 9 thermocouples embedded in the heated heat sink face while water flowed through it at rates of 100–1500 mL/min. The optimized heat sink maintained lower surface temperatures and reduced temperature non-uniformity on its surface at all flow rates tested. Numerical simulations demonstrated that this was due to better flow distribution by the topologically optimized flow channels.

Effects of different water-cooled heat sinks on the cooling system performance in a data center

Data center, as a special building form, has attracted much attention because of its increasing energy consumption. In order to reduce the energy consumption of data center caused by cooling system, research on the water-cooled heat sinks used to cool chips has become increasingly important with the steep increase in the heat flux density of data centers. To explore the effect of different water-cooled heat sinks on cooling system performance, a server water-cooled system for the server cabinet was built, and the chip heat dissipation performance, optimal thermal management, and system energy consumption were simulated by equipping a cooling tower and two types of fin-type water-cooled heat sinks (A-type and B-type). By comparing the effects of A- and B-type heat sinks on the server water-cooled system performance, the optimal water working condition was obtained under different atmospheric conditions by minimizing the system power consumption to guarantee that the chip temperature is no higher than 70 °C. It was found that the optimal cooling water flow rate fluctuates in a large range under different atmospheric conditions. A server water-cooled system equipped with B-type can achieve significant energy savings compared to those from A-type system when the atmospheric relative humidity and temperature are high. Considering a case study from Tianjin, China, it is shown that the month-averaged power usage effectiveness in June is 1.2 for A-type and 1.14 for B-type systems.

Jet microchannel with sawtooth wall for efficient cooling of high-power electronics

Dissipation of ultrahigh heat fluxes is critical to modern electronic chips as they become ever more compact and powerful. Here, by employing a systematic numerical study, we present a highly-efficient embedded single-phase water-cooled silicon heat sink featuring a manifold with interdigitated inlets and outlets and jet microchannels with sawtooth side walls. Compared to straight channels, the sawtooth walls reduce blockage of the jet inflow and therefore the pressure drop. Meanwhile, the sawtooth profile helps suppress the large recirculation region around the jet inlet and generate small vortices near the channel walls which facilitate fluid mixing and enhance heat exchange. This simultaneous enhancement of heat transfer and reduction of pressure drop leads to some of the highest cooling efficiencies. In particular, for a 3 × 3 mm2 chip at a temperature rise of 60 K, dissipation of heat fluxes over 2100 W cm−2 is possible with a pumping power of about 1.3 W cm−2. For heat fluxes around 1000 W cm−2, the coefficient of performance can reach beyond 20,000. In addition to the high performance, our heat sink can in principle be manufactured via standard silicon microfabrication technology.

Liquid-cooled heat sink design for a multilevel inverter switch with considerations for heat spreading and manufacturability

Multilevel inverter switches (MIS) present a thermal management challenge by virtue of their small size yet high power operation. In this contribution, a water-cooled heat sink for an MIS was designed and optimized through a series of computational fluid dynamics simulations and surrogate modeling. The parameters under consideration were technical metrics (thermal resistance, pressure loss, and temperature uniformity) and manufacturing costs. The stark difference between air-cooled and liquid-cooled heat sinks was demonstrated in parallel modeling efforts. The heat sink consisted of a metallic baseplate with pin-fins and a separate resin manifold containing an array of nozzles for flow impingement and fluid extraction. The pin–fin baseplate was parametrically designed using three different fin densities: restricted array (RA), variable array semifull (VAS), and variable array (VA), where fin diameter and pitch were correlated. The manufacturability of each design iteration was determined by obtaining quotes from a vendor. Since all heat sinks had the same inlet manifold, the pressure drop was similar across heat sink designs, indicating that the fin distribution had a minimum effect on the overall pumping power required for circulating the flow through the heat sinks. Effective thermal resistance calculations illustrated a complex interplay between fin diameter and pitch spacing. The complexity was better visualized using a feedforward neural network (FNN) and an overall performance metric (PPTR). A sensibility analysis using the FNN indicated that the fin pitch was the dominant variable in the determination of the overall heat sink performance. The PPTR allowed the creation of a ranking system that matched the FFN outcome and indicated that the VA2D1 design was the most technically promising; nonetheless, once manufacturing cost was considered in the analysis, as PPTR-$, the RA1D1 was the most commercially viable as it satisfied technical cooling goals per the lowest unit cost.

Experimental Evaluation of the Thermoelectrical Performance of Photovoltaic-Thermal Systems with a Water-Cooled Heat Sink

A design for a photovoltaic-thermal (PVT) assembly with a water-cooled heat sink was planned, constructed, and experimentally evaluated in the climatic conditions of the southern region of Iraq during the summertime. The water-cooled heat sink was applied to thermally manage the PV cells, in order to boost the electrical output of the PVT system. A set of temperature sensors was installed to monitor the water intake, exit, and cell temperatures. The climatic parameters including the wind velocity, atmospheric pressure, and solar irradiation were also monitored on a daily basis. The effects of solar irradiation on the average PV temperature, electrical power, and overall electrical-thermal efficiency were investigated. The findings indicate that the PV temperature would increase from 65 to 73 °C, when the solar irradiation increases from 500 to 960 W/m2, with and without cooling, respectively. Meanwhile, the output power increased from 35 to 55 W when the solar irradiation increased from 500 to 960 W/m2 during the daytime. The impact of varying the mass flow rate of cooling water in the range of 4 to 16 L/min was also examined, and it was found that the cell temperature declines as the water flow increases in intensity throughout the daytime. The maximum cell temperature recorded for PV modules without cooling was in the middle of the day. The lowest cell temperature was also recorded in the middle of the day for a PVT solar system with 16 L/min of cooling water.

Topology optimization for a water-cooled heat sink in micro-electronics based on Pareto frontier

• An efficient Pareto frontier based design strategy for heat sinks is proposed. • A fitting formula of the Pareto frontiers is introduced to accelerate the design. • The 2D topology design results are validated by 3D CFD simulations. • Effects of temperature dependent properties on the results are significant. Topology optimization has been increasingly adopted as a non-intuitive methodology for heat sink design in the thermal management of microelectronics. In this work, a bi-objective topology optimization method for heat sink design in micro-electronics is suggested by considering the trade-off between two contradicting objectives, i.e., the heat transfer and hydraulic performances. The method in this work focused on the laminar water flow with Reynolds number less than 100 based on the channel width for a wide temperature range that covers different types of micro-electric devices. A series of Pareto frontiers were acquired for heat sink designs with different topologies, which can be used to decide the optimum design in respect of heat transfer and pressure drop. Particularly, an analytical formula in terms of inlet Reynolds numbers was obtained for the fast generation of the Pareto frontiers under different working conditions which help to determine the weight parameters of two contradicting objectives readily. The new strategy for weight parameter determination significantly reduces the workload of trial-and-error during the weight parameter determination in the traditional bi-objective topology optimization and thus accelerates the design process. Besides, the temperature-dependent physical properties (viscosity and thermal conductivity) in the design model were considered and were found to affect the design results significantly. Finally, the 3D heat sink model was reconstructed from the 2D topology optimization, and the thermal-fluid analyses were conducted. The results indicate that the 3D reconstructed model can well satisfy the design objective specified in the topology optimization, thereby confirming the validity and robustness of our design method.

Optimal thermal management of server cooling system based cooling tower under different ambient temperatures

• A new model is introduced to analyze year-round cooling system power consumption. • Optimal water operation conditions under different ambient temperatures are given. • Year-round energy consumption analysis is done by taking Tianjin as a study case. • Significant year-round cooling power can be saved by optimizing thermal parameters. To develop a highly efficient and energy-saving cooling system in a data center, this study investigates the optimal thermal management both on the internal server cooling cycle and external cold source water cycle under different ambient temperatures based on the principle of minimal power consumption. Taking a server cabinet of 4.8 kW as the case, an internal indirect water-cooled heat sink cycle and an external cooling tower cold source cycle are constructed. A hybrid thermal management model combined with a heat dissipation model and a power consumption model was developed with the aid of MATLAB and TRNSYS. Using this model, the relationship between the chip dissipation performance attached to the fin-type heat sink and the energy consumption performance of the cooling system under different water working conditions and ambient temperatures was analyzed. Finally, to achieve minimal system energy consumption, the optimized inlet temperature and water flow rates corresponding to different ambient temperatures were obtained by fitting expressions that can better serve the optimal design of data center cooling systems. Furthermore, when the optimal value was applied using the year-round temperature of Tianjin, China in the case study, a 21.3% reduction in power consumption and a 4.43% decrease in the power usage effectiveness can be achieved compared to the case without optimization. Therefore, significant power can be saved in a data center cooling system through thermal management optimization.

Heat Dissipation Characteristics of IGBT Module Based on Flow-Solid Coupling.

With the increase of power level and integration in electric vehicle controllers, the heat flux of the key silicon-based IGBT (Insulated Gate Bipolar Transistor) device has reached its physical limit. At present, third-generation semiconductor devices including SiC MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistor) are gradually replacing the dominant IGBT module. The hybrid IGBT module consists of both and can improve the performance and reduce the cost of controllers. Limits due to the installation space, location, and other conditions in the car make it difficult to meet the requirements of controllers with an air-cooled heatsink due to their large size and limited heat dissipation capacity. A smaller and more powerful water-cooled heatsink case is required to ensure the heat dissipation of the IGBT in the controller. Based on previous experience in finite element numerical simulation, hydrodynamics calculation, and heat transfer calculation, ANSYS Workbench finite element software was used to analyze the thermal resistance of each structure inside the module and the heatsink structure. The fluid characteristics and heat transfer performance of three different flow channel structures were analyzed, and the design of the cooling flow fin was improved to provide a reference for the heat dissipation of the hybrid IGBT module.

Experiments on Waste Heat Thermoelectric Generation for Passenger Vehicles.

In order to utilize waste heat from passenger vehicles by a thermoelectric generator (TEG), a lab-scale TEG with a sufficient low-pressure drop was designed and tested. The waste heat from a 2.0 L petrol engine was simulated by using an air-circulation channel with an adjustable electric heater and a speed control motor. The TEG consisted of an integrated molding designed aluminum-finned heat collector, twenty thermoelectric modules, and a set of water-cooled heat sinks. Experiments were conducted in terms of power load feature, pressure drop, heat collection efficiency, thermoelectric efficiency and overall efficiency. It was found that the hot-end temperature was much lower (46.9%) than the flue gas temperature because the trade-off between fin area and pressure drop had to be considered. The obtained maximum electric power was 36.4 W, and the corresponding pressure drop was 36 Pa. The corresponding heat collection efficiency was 46.5%, and the thermoelectric efficiency was 2.88%, which agreed well with the theoretical prediction of 3.38%. As a result, an overall efficiency of 1.21% was reached. The present work firstly demonstrated a waste-heat-recovering TEG prototype with a balanced overall efficiency of over 1%, and a pressure drop of less than 50 Pa. On the other hand, the maximum electric power was difficult to fully extract. The charging power to a battery with a maximum power point tracking direct current–direct current converter was experimentally verified to work at a much higher conversion efficiency (15.3% higher) than regular converters.

Numerical investigation of the effect of flow circulation pattern and velocity on the performance of water-cooled heat sink

The most critical problems of electronic components are the high power consumption and lesser life. This paper aims to numerically model the working process of the water-cooled heat sink to obtain the most effective design. In this context, four types of configurations with different passes (Type-A, Type-B, Type-C, Type-D) were designed at different water velocities, which were 0.25 m/s, 0.5 m/s, and 1 m/s with constant air velocity (6 m/s) to simulate fluid flow and the heat transfer. Results were evaluated as temperature and pressure contours, velocity streamlines, and the graphics of pressure difference, outlet temperature, temperature difference, heat transfer rate to air, and power consumption in relation to Reynolds number. Results showed that pressure difference, outlet temperature, power consumption, and heat transfer rate to air increased by increasing Reynolds number in all analyses. In all configurations, the water outlet temperatures were very close to each other, in the range of 63-65 °C for Re=2500, 70-72 °C for Re=5000, and 74-76 °C for Re=10000. Among all configurations, Type-A has the minimum outlet temperature with the value of 63.40 °C for Re=2500, 70.77 °C for Re=5000, and 74.85 °C for Re=10000. Also, Type-A showed better performance than other models in terms of heat transfer rate to air with the value of 1346 W for Re=2500, 1500 W for Re=5000, and 1675 W for Re=10000. The maximum pressure difference was obtained in Type-A geometry with the value of nearly 3500 Pa at a Reynolds number value of 10000. When the results were evaluated in full scope, it was concluded that Type-B was the most suitable model for use in terms of heat transfer, pump power, and inlet-outlet positions.

A novel double-sided cooling packaging structure of SiC-based half bridge module integrating the laminated busbar

This paper presents a novel double-sided cooling SiC-based half-bridge (HB) module with laminated busbar. The novelty of this module lies in the integration of a laminated busbar which can result in a significant reduction of the module parasitic inductance. Moreover, a 3D vertical structure design can reduce the commutation loop area inside the module, thereby further achieving a lower commutation loop inductance. Meanwhile, this module achieves wire-free bonding that can improve the reliability of the power module to a certain extent. A fan-shaped DBC layout is designed to ensure the symmetrical layout of the paralleled chips, which can realize a better current sharing performance. In fact, an unbalanced junction temperature can also affect the current balance of each parallel device, resulting in unequal turn-on and turn-off losses. Therefore, a three-outlet circular water-cooled heat sink is proposed to ensure the junction temperature balance of the parallel chips, which is demonstrated by thermal simulation. Then, by the Ansys Q3D, the extracted parasitic inductance of the module is about 5.63 nH, and the imbalance degree between each parallel branch is about 5.8%. Finally, the low parasitic inductance and highly symmetry of the module are verified by the experimental tests.

Thermal Performance Investigation of Slotted Fin Minichannel Heat Sink for Microprocessor Cooling

Due to high heat flux generation inside microprocessors, water-cooled heat sinks have gained special attention. For the durability of the microprocessor, this generated flux should be effectively removed. The effective thermal management of high-processing devices is now becoming popular due to high heat flux generation. Heat removal plays a significant role in the longer operation and better performance of heat sinks. In this work, to tackle the heat generation issues, a slotted fin minichannel heat sink (SFMCHS) was investigated by modifying a conventional straight integral fin minichannel heat sink (SIFMCHS). SFMCHSs with fin spacings of 0.5 mm, 1 mm, and 1.5 mm were numerically studied. The numerical results were then compared with SIFMCHSs present in the literature. The base temperatures recorded for two slots per fin minichannel heat sink (SPFMCHS), with 0.5 mm, 1 mm, and 1.5 mm fin spacings, were 42.81 °C, 46.36 °C, and 48.86 °C, respectively, at 1 LPM. The reductions in base temperature achieved with two SPFMCHSs were 9.20%, 8.74%, and 7.39% for 0.5 mm, 1 mm, and 1.5 mm fin spacings, respectively, as compared to SIFMCHSs reported in the literature. The reductions in base temperature noted for three SPFMCHSs were 8.53%, 9.05%, and 5.95% for 0.5 mm, 1 mm, and 1.5 mm fin spacings, respectively, at 1 LPM, as compared to SIFMCHSs reported in the literature. In terms of heat transfer performance, the base temperature and thermal resistance of the 0.5 mm-spaced SPFMCHS is better compared to 1 mm and 1.5 mm fin spacings. The uniform temperature distribution at the base of the heat sink was observed in all cases solved in current work.