A Study of Liquid Cooling Heat Sink Fabrication and Development in Notebook

2006 ◽  
Vol 505-507 ◽  
pp. 223-228
Author(s):  
A Cheng Wang ◽  
Kuo Zoo Liang ◽  
C.C. Liu ◽  
C.K. Yang
Keyword(s):  
Heat Sink ◽  
Electrical Discharge ◽  
Heat Dissipation ◽  
Electrical Discharge Machining ◽  
Liquid Cooling ◽  
Working Surface ◽  
Erosion Effect ◽  
Long Pulse ◽  
Cutting Path ◽  
Off Time

Liquid cooling heat sink has excellent heat dissipation ability at the personal computer. It can also produce the similar effect at the notebook when the same heat sink is used. However, under the installing space is limited in notebook, the size and weight of heat sink must be limited too. Therefore a novel liquid cooling heat sink was fabricated herein to understand the heat dissipation efficiency in the notebook. Wire electrical discharge machining (WEDM) uses heat erosion effect to remove material and only produces little cutting force on the working surface. Therefore, WEDM has excellent ability to fabricate the straight micro fins (high 1000 μm, width 250 μm, fin gap 400 μm). The WEDM parameters were used to find the precision micro fins in this experiment. The precision micro fins were made when the cutting path offset was 185 μm in WEDM. WEDM would produce over cutting during long pulse duration and it caused oblique micro fins. The appropriate off time in cutting process would promote the WEDM efficiency. However, a liquid cooling heat sink with uniform micro fins and slits was obtained using WEDM.

Design and Tests of a Water-Cooling Micro-Channel Heat Sink Made by WEDM

2012 ◽  
Vol 459 ◽  
pp. 609-614
Author(s):  
Kuo Zoo Liang ◽  
A Cheng Wang ◽  
Chun Ho Liu ◽  
Lung Tasi ◽  
Yan Cherng Lin
Keyword(s):  
Thermal Resistance ◽  
Heat Sink ◽  
Electrical Discharge ◽  
Heat Dissipation ◽  
Electrical Discharge Machining ◽  
Input Power ◽  
Wire Electrical Discharge Machining ◽  
Micro Channel ◽  
Water Cooling ◽  
Computer Aided

The purpose of this research is to design a new heat sink of water-cooling. With the aid of CAE (computer aided engineering), WEDM (wire electrical discharge machining), and the concept of micro-channel design, a heat sink of water-cooling can then be built with the merit of a smaller volume and lower thermal resistance. From this paper, results of the experiment indicate that the thermal resistance of heat sink can be decreased to 0.12 °C/W with input power of 60W, flow rate of 0.6 LPM, and a better heat dissipation with the in input power of 100W or 140W can be revealed.

Mathematical Modeling of Machining Parameters in Electrical Discharge Machining with Cu-B4C Composite Electrode

2012 ◽  
Vol 488-489 ◽  
pp. 871-875
Author(s):  
V. Anandakrishnan ◽  
V. Senthilkumar
Keyword(s):  
Mathematical Models ◽  
Current Pulse ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Machining Parameters ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Off Time ◽  
Selection Of

Copper based metal matrix composite reinforced with Boron Carbide is a newly developed Electrical Discharge Machining (EDM) electrode showing better performance than the conventional copper based electrode. Right selection of machining parameters such as current, pulse on time and pulse off time is one of the most important aspects in EDM. In this paper an attempt has been made to develop mathematical models for relating the Material Removal Rate (MRR), Tool Removal Rate (TRR) and Surface roughness (Ra) to machining parameters (current, pulse-on time and pulse-off time). Furthermore, a study was carried out to analyze thSubscript texte effects of machining parameters on various performance parameters such as, MRR, TRR and Ra. The results of Analysis of Variance (ANOVA) indicate that the proposed mathematical models, can adequately describe the performance within the limits of the factors being studied. Response surface modeling is used to develop surface and contour graphs to analyze the effects of EDM input parameters on outer parameters.

A Truing Technique of Flattening Diamond Grains for Fabricating Microstructures with Fine Surfaces

2008 ◽  
Vol 389-390 ◽  
pp. 350-355
Author(s):  
Takeshi Harada ◽  
Takuya Semba
Keyword(s):  
Surface Roughness ◽  
Electrical Discharge ◽  
Diamond Tool ◽  
Electrical Discharge Machining ◽  
Polycrystalline Diamond ◽  
Mesh Size ◽  
Diamond Disk ◽  
Working Surface ◽  
Work Material ◽  
Tool Profile

A truing technique that can be used to shape the tip of an electroformed diamond tool into a hemisphere and flatten diamond grains on the tool working surface at the same level as the bond face was developed. A polycrystalline diamond disk whose top surface roughened by electrical discharge machining was partially flattened by grinding was used as a truer. Diamond grains on the tool working surface were successfully flattened along the hemispherical tool profile when the grains mesh size of #1000 was employed. In addition, a grinding test using glasslike carbon as a work material revealed that a surface roughness of less than 50 nm Rz could be obtained in both cases when moving the tool on contour and scanning paths.

Design and characterization of a copper microchannel heat sink for SiP cooling

2021 ◽  
pp. 2140015
Author(s):  
Min Miao ◽  
Hao Zhang ◽  
Hejie Yu ◽  
Lili Cao
Keyword(s):  
Heat Flux ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Electrical Discharge Machining ◽  
Copper Substrate ◽  
Integrated System ◽  
Peak Temperature ◽  
Microchannel Heat Sink ◽  
Set Up ◽  
Electronic Hardware

With the increasing flourishing of miniaturized, multifunctional, and heterogeneously integrated system in package (SiP), heating problem is becoming more and more serious. In this paper, to meet the heat dissipation needs of the chips thus assembled and to achieve effective thermal management, linear, serpent and spiral shaped microchannel heat sinks were designed and fabricated into copper substrate by electrical discharge machining (EDM) and precision machining technology, acting both as the cooler and mounting base for passive and active SiP interposers. A test platform was set up to characterize the heat dissipation performance of the copper-based microchannel heat sink. The experimental and simulation results show that heat dissipation rate increases with the increasing heat flux density in the range 5–30 W/cm2 for the three microchannel designs, and the peak temperature can all be kept below 340 K (67[Formula: see text]C) even for the highest heat flux. The three designs are compared from the perspective of peak temperature, temperature distribution uniformity and pressure drop. In all, the solution proposed hereby provides a new and optimal option for in-situ cooling for densely integrated electronic hardware.

Experimental Evaluation on Corner Accuracy in WEDM for Aluminium 6061 Alloy

2021 ◽  
pp. 96-113
Author(s):  
Debal Pramanik ◽  
Dipankar Bose
Keyword(s):  
Electrical Discharge ◽  
Thermal Process ◽  
Electrical Discharge Machining ◽  
Sharp Corner ◽  
Proposed Model ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Off Time ◽  
Wire Feed ◽  
Time Pulse

An important electro-thermal process known as wire electrical discharge machining (WEDM) is applied for machining of conductive materials to generate most precisely. All cutting inaccuracies of WEDM arise out of the major cause of wire bending. At the time of cutting a sharp corner or cut profile, bending of the wire leads to a geometrical error on the workpiece. Though this type of error may be of a few hundred microns, it is not suitable for micro applications. In this research study, an experimental investigation based on response surface methodology (RSM) has been done on wire EDM of Aluminium 6061 t6 alloy. This chapter studies the outcome of input process variables (i.e., wire feed rate, pulse on time, pulse off time, and gap voltage) on machining output responses (i.e., corner inaccuracy) extensively. Experimental validation of the proposed model shows that corner inaccuracy value may be reduced by modification of input parameters.

Relationship between the Fine Discharge Parameters and Craters EDMed of the NAK80 Steel

2010 ◽  
Vol 426-427 ◽  
pp. 85-88
Author(s):  
Hong Jun Wang ◽  
Dun Wen Zuo ◽  
X.M. Wu ◽  
M. Wang
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Discharge Voltage ◽  
Optimization Scheme ◽  
Crater Diameter ◽  
Open Discharge ◽  
Discharge Parameters ◽  
Pulse Off Time ◽  
Off Time ◽  
Edm Process

The crater diameter and depth of the surface machined by electrical discharge machining (EDM) were used to evaluate indexes for EDMed surface. The influence of discharge parameters selected on the crater diameter and depth in mirror-like surface EDM process was investigated, and the optimization scheme was obtained. An L16 (44×23) Taguchi standard orthogonal array was chosen for the design of experiments. Experimental results indicate that peak current and open discharge voltage have more influence on the crater diameter and depth in comparison with pulse off-time and pulse duration. Also the results confirm that the crater depth is about 10 to 20 percent of its diameter while the near-mirror EDM conducted in the NAK80 steel with fine discharge parameters.

Deep Hole of AISI P20 Mold Steel Material by Electrical Discharge Machining

2014 ◽  
Vol 590 ◽  
pp. 244-248
Author(s):  
Jamkamon Kamonpong ◽  
Pichai Janmanee
Keyword(s):  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Side Surface ◽  
Copper Electrode ◽  
Electrode Wear ◽  
Steel Material ◽  
Suitable Parameter ◽  
Aisi P20 ◽  
Off Time

This research aimed to study the machining efficiency of AISI P20 steel by Electrical Discharge Machining (EDM) using rod copper electrode to machining material by 50 mm depth of machining was mainly assessed from Materials Removal Rate (MRR) and Electrode Wear Ratio (EWR). From the experiment designed to use Taguchi technique of data analysis and suitable parameter prediction, the highest MRR was at on-time of 150 μs, off-time of 2 μs and electric current level was at 15 A or 0.25 A/mm2. Predicted value was at 19.2395 mm3/min which was equal to real experiment, showing Materials Removal Rate of 19.647 mm3/min (with error of 2.12 percent) .Moreover, it was found that gap would increase with the size of electrode and depth of machining caused by movement of particles removed from side surface of electrode, which cause micro sparks at the side of the material workpiece.

Study the Re-Sticky Phenomenon of Powder Metallurgy Debris in the Electrical Discharge Machining

2009 ◽  
Vol 83-86 ◽  
pp. 968-976
Author(s):  
A Cheng Wang ◽  
Ken Chuan Cheng ◽  
Yan Cherng Lin ◽  
Jeng Shen Huang
Keyword(s):  
Powder Metallurgy ◽  
Melting Point ◽  
Rotational Speed ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Negative Polarity ◽  
Melting Points ◽  
Working Surface ◽  
Adhesive Effect

The debris re-adhering on the machining surface will affect the workpiece precision in EDM; therefore, the main purpose of this research is to study the re-sticky phenomenon of the powder metallurgy (PMM) in EDM. PMM with different melting points from 1450oC to 3410oC were used as EDM materials, the copper and the tungsten were chosen as the electrodes. The polarity in EDM was depended on the pole of the electrode. For observing the re-sticky position of the debris, the electrode was set no rotation or with 200 rpm rotational speed in EDM. The results showed that the melting point of PMM did not exceed 3000oC (PMM did not contain tungsten); the debris of PMM would not re-stick on the working surface no matter what polarity was used in EDM. However, only negative polarity can cause the re-adhesive effect when the melting point of PMM exceeded 3000oC. The debris would re-stick on any machining position when the electrode was not rotated in EDM. However, the debris would adhere on the central of the working area with 200 rpm rotational speed of the electrode.

Influence of Process Parameters on Characteristics of Electrical Discharge Machining of PH17-4 Stainless Steel

2015 ◽  
Vol 14 (03) ◽  
pp. 189-202 ◽  
Author(s):  
V. Vikram Reddy ◽  
P. Madar Valli ◽  
A. Kumar ◽  
Ch. Sridhar Reddy
Keyword(s):  
Material Removal Rate ◽  
Electrical Discharge ◽  
Material Removal ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Surface Hardness ◽  
Machining Process ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Off Time

In the present work, an investigation has been made into the electrical discharge machining process during machining of precipitation hardening stainless steel PH17-4. Taguchi method is used to formulate the experimental layout, to analyze the effect of each process parameter on machining characteristics and to predict the optimal choice for each electrical discharge machining process parameters namely, peak current, pulse on time and pulse off time that give up optimal process performance characteristics such as material removal rate, surface roughness, tool wear rate and surface hardness. To identify the significance of parameters on measured response, the analysis of variance has been done. It is found that parameters peak current and pulse on time have the significant affect on material removal rate, surface roughness, tool wear rate and surface hardness. However, parameter pulse off time has significant affect on material removal rate. Confirmation tests are conducted at their respective optimum parametric settings to verify the predicted optimal values of performance characteristics.

Surface Roughness Optimization of Wire Electrical Discharge Machining Using ABC Algorithm

2015 ◽  
Vol 766-767 ◽  
pp. 902-907
Author(s):  
Bibin K. Tharian ◽  
B. Kuriachen ◽  
Josephkunju Paul ◽  
Paul V. Elson
Keyword(s):  
Surface Roughness ◽  
Process Parameters ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Wire Electrical Discharge Machining ◽  
Wire Tension ◽  
Pulse On Time ◽  
Pulse Off Time ◽  
Off Time ◽  
Wire Feed

Wire electrical discharge machining is one of the important non-traditional machining processes for machining difficult to machine materials. It involves the removal of material by the discrete electric discharges produced between the inter electrode gap of continuously moving wire electrode and the work piece. The ability to produce intricate profiles on materials irrespective of the mechanical properties made this process to be widely used in industries. The present study investigates the relationship of various process parameters in WEDM of AISI 202 stainless steel with brass electrode.The experiments were planned according to Taguchi’s L18 orthogonal array and experimental models were developed. The important process parameters identified for the present study were pulse on time, peak current, pulse off time, wire feed, wire tension, dielectric flushing pressure, servo feed and gap voltage. The surface roughness of the machined surface was measured as the process performance measure. Analysis of variance test has also been carried out to check the adequacy of the developed models and to identify the level of significance of each process parameters. In addition to the developed models, ABC optimization has been performed to identify the optimum parameter combination for minimum surface roughness and the obtained optimal process parameters are peak current 11 A, pulse on time 100 μs, pulse off time 49 μs, wire feed 4 m/min, wire tension 10 N, flushing pressure 12 kg/cm2, servo feed 2100 mm/min and set gap voltage 30 V. Finally the results were verified with the experimental results and found that they are in good agreement.

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