Conjugate Analysis of Thin Film Heat Spreaders to Reduce Temperature at Hot Spots

2015 ◽  
Author(s):  
Sohail R. Reddy ◽  
Abas Abdoli ◽  
George S. Dulikravich ◽  
Rajesh Jha
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Hot Spot ◽  
Three Dimensional ◽  
Effective Area ◽  
Heat Transfer Analysis ◽  
Maximum Temperature ◽  
Film Material ◽  
Electric Circuits ◽  
Heat Spreaders

The effects of thin film coating on maximum temperature of integrated electric circuits are investigated. A fully three-dimensional conjugate heat transfer analysis was performed to investigate the effects of thin film material and thickness on the temperature of a hot spot. Two different materials, diamond and graphene nano-platelets were simulated as materials for thin films. The thin film heat spreaders were applied to the top wall of the three optimized arrays of micro pin-fins having circular, airfoil and convex cross sections. The electronic chip with a 4 × 3 mm footprint featured a 0.5 × 0.5 mm hot spot located on the top wall which was exposed to a uniform high-level background heat flux. The effective area of coverage of the thin films was also investigated computationally. It was found that thin film heat spreaders significantly reduce the hot spot temperature, allowing for increased thermal loads and therefore increased performance. Furthermore, it was found that thickness of the thin film heat spreader does not have to be greater than a few tens of microns.

Effects of Thin Film Heat Spreader on Hot Spots Mitigation in Heat Sinks

2021 ◽  
pp. 1-17
Author(s):  
Sohail Reddy ◽  
George S. Dulikravich ◽  
Ann-Kayana Blanchard
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Heat Flux ◽  
Integrated Circuit ◽  
Conjugate Heat Transfer ◽  
Hot Spot ◽  
Heat Transfer Analysis ◽  
Temperature Uniformity ◽  
Heat Spreader ◽  
Heat Spreaders

Abstract The effects of graphene platelets and diamond based thin film heat spreaders on maximum temperature of integrated electronic circuits were investigated. A fully three-dimensional conjugate heat transfer analysis was performed to investigate the effects of thin film material and thickness on the temperature of a hot spot and temperature uniformity on the heated surface of the integrated circuit when subjected to forced convective cooling. Two different materials, diamond and graphene were simulated as materials for thin films. The thin film heat spreaders were applied to the top wall of an array of micro pin-fins having circular cross sections. The integrated circuit with a 4 × 3 mm footprint featured a 0.5 × 0.5 mm hot spot located on the top wall which was also exposed to a uniform background heat flux of 500 W cm−1. A hot spot uniform heat flux of magnitude 2000 W cm−2 was centrally situated on the top surface over a small area of 0.5 × 0.5 mm. Both isotropic and anisotropic properties of the thin film heat spreaders made of graphene platelets and diamond were computationally analyzed. The conjugate heat transfer analysis incorporated thermal contact resistance between the thin film and the silicon substrate. The isotropic thin film heat spreaders significantly reduced the hot spot temperature and increased temperature uniformity, allowing for increased thermal loads. Furthermore, it was found that thickness of the thin film heat spreader need not be greater than a few tens of microns

The Optical Properties of Thin Films Tin Oxide with Triple Doping (Aluminum, Indium, and Fluorine) for Electronic Device

2021 ◽  
Vol 317 ◽  
pp. 477-482
Author(s):  
Aris Doyan ◽  
Susilawati ◽  
Muhammad Taufik ◽  
Syamsul Hakim ◽  
Lalu Muliyadi
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Activation Energy ◽  
Optical Properties ◽  
Tin Oxide ◽  
Electronic Device ◽  
Film Material ◽  
Mass Percentage ◽  
Gap Energy ◽  
As Doping

Tin oxide (SnO2) thin film is a form of modification of semiconductor material in nanosize. The thin film study aims to analyze the effect of triple doping (Aluminum, Indium, and Fluorine) on the optical properties of SnO2: (Al + In + F) thin films. Aluminum, Indium, and Fluorine as doping SnO2 with a mass percentage of 0, 5, 10, 15, 20, and 25% of the total thin-film material. The addition of Al, In, and F doping causes the thin film to change optical properties, namely the transmittance and absorbance values ​​changing. The transmittance value is 67.50, 73.00, 82.30, 87.30, 94.6, and 99.80 which is at a wavelength of 350 nm for the lowest to the highest doping percentage, respectively. The absorbance value increased with increasing doping percentage at 300 nm wavelength of 0.52, 0.76, 0.97, 1.05, 1.23, and 1.29 for 0, 5, 10, 15, 20, and 25% doping percentages, respectively. The absorbance value is then used to find the gap energy of the SnO2: (Al + In + F) thin film of the lowest doping percentage to the highest level i.e. 3.60, 3.55, 3.51, 3.47, 3.42, and 3.41 eV. Thin-film activation energy also decreased with values of 2.27, 2.04, 1.85, 1.78, 1.72, and 1.51 eV, respectively for an increasing percentage of doping. The thin-film SnO2: (Al + In + F) which experiences a gap energy reduction and activation energy makes the thin film more conductive because electron mobility from the valence band to the conduction band requires less energy and faster electron movement as a result of the addition of doping.

scholarly journals Tip-Based Nanomachining on Thin Films: A Mini Review

2021 ◽  
Author(s):  
Shunyu Chang ◽  
Yanquan Geng ◽  
Yongda Yan
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Data Storage ◽  
Three Dimensional ◽  
Maintenance Cost ◽  
Two Dimensional ◽  
Force Microscopy ◽  
Atomic Force ◽  
Current State ◽  
Two Dimensional Materials

AbstractAs one of the most widely used nanofabrication methods, the atomic force microscopy (AFM) tip-based nanomachining technique offers important advantages, including nanoscale manipulation accuracy, low maintenance cost, and flexible experimental operation. This technique has been applied to one-, two-, and even three-dimensional nanomachining patterns on thin films made of polymers, metals, and two-dimensional materials. These structures are widely used in the fields of nanooptics, nanoelectronics, data storage, super lubrication, and so forth. Moreover, they are believed to have a wide application in other fields, and their possible industrialization may be realized in the future. In this work, the current state of the research into the use of the AFM tip-based nanomachining method in thin-film machining is presented. First, the state of the structures machined on thin films is reviewed according to the type of thin-film materials (i.e., polymers, metals, and two-dimensional materials). Second, the related applications of tip-based nanomachining to film machining are presented. Finally, the current situation of this area and its potential development direction are discussed. This review is expected to enrich the understanding of the research status of the use of the tip-based nanomachining method in thin-film machining and ultimately broaden its application.

Clocking Effects of Inlet Non-Uniformities in a Fully Cooled High-Pressure Vane: A Conjugate Heat Transfer Analysis

2015 ◽  
Author(s):  
Duccio Griffini ◽  
Massimiliano Insinna ◽  
Simone Salvadori ◽  
Francesco Martelli
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Film Cooling ◽  
Conjugate Heat Transfer ◽  
Cooling System ◽  
Hot Spot ◽  
Three Dimensional ◽  
Leading Edge ◽  
Suction Side ◽  
Heat Transfer Analysis

A high-pressure vane equipped with a realistic film-cooling configuration has been studied. The vane is characterized by the presence of multiple rows of fan-shaped holes along pressure and suction side while the leading edge is protected by a showerhead system of cylindrical holes. Steady three-dimensional Reynolds-Averaged Navier-Stokes (RANS) simulations have been performed. A preliminary grid sensitivity analysis with uniform inlet flow has been used to quantify the effect of spatial discretization. Turbulence model has been assessed in comparison with available experimental data. The effects of the relative alignment between combustion chamber and high-pressure vanes are then investigated considering realistic inflow conditions in terms of hot spot and swirl. The inlet profiles used are derived from the EU-funded project TATEF2. Two different clocking positions are considered: the first one where hot spot and swirl core are aligned with passage and the second one where they are aligned with the leading edge. Comparisons between metal temperature distributions obtained from conjugate heat transfer simulations are performed evidencing the role of swirl in determining both the hot streak trajectory within the passage and the coolant redistribution. The leading edge aligned configuration is resulted to be the most problematic in terms of thermal load, leading to increased average and local vane temperature peaks on both suction side and pressure side with respect to the passage aligned case. A strong sensitivity of both injected coolant mass flow and heat removed by heat sink effect has also been highlighted for the showerhead cooling system.

Simulation of 3D Films Deposited by Glancing Angle Deposition Using 3D-Films

2000 ◽  
Vol 616 ◽  
Author(s):  
T. Smy ◽  
D. Vick ◽  
M. J. Brett ◽  
S. K. Dew ◽  
A. T. Wu ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Three Dimensional ◽  
Thin Film Deposition ◽  
Glancing Angle Deposition ◽  
Film Deposition ◽  
Porous Thin Films ◽  
Glancing Angle ◽  
Memory Resources ◽  
Angle Deposition

AbstractA new fully three dimensional (3D) ballistic deposition simulator 3D-FILMS has been developed for the modeling of thin film deposition and structure. The simulator may be implemented using the memory resources available to workstations. In order to illustrate the capabilities of 3D-FILMS, we apply it to the growth of engineered porous thin films produced by the technique of GLancing Angle Deposition (GLAD).

Inverse Design of Cooling of Electronic Chips Subject to Specified Hot Spot Temperature and Coolant Inlet Temperature

2015 ◽  
Author(s):  
Sohail R. Reddy ◽  
George S. Dulikravich
Keyword(s):  
Heat Flux ◽  
Hot Spot ◽  
Heat Fluxes ◽  
Operating Conditions ◽  
Heat Transfer Analysis ◽  
Maximum Temperature ◽  
Fluid Temperature ◽  
Cooling Fluid ◽  
Pin Fin ◽  
The Given

Most methods for designing electronics cooling schemes do not offer the information on what levels of heat fluxes are maximally possible to achieve with the given material, boundary and operating conditions. Here, we offer an answer to this inverse problem posed by the question below. Given a micro pin-fin array cooling with these constraints: - given maximum allowable temperature of the material, - given inlet cooling fluid temperature, - given total pressure loss (pumping power affordable), and - given overall thickness of the entire electronic component, find out the maximum possible average heat flux on the hot surface and find the maximum possible heat flux at the hot spot under the condition that the entire amount of the inputted heat is completely removed by the cooling fluid. This problem was solved using multi-objective constrained optimization and metamodeling for an array of micro pin-fins with circular, airfoil and symmetric convex cross sections that is removing all the heat inputted via uniform background heat flux and by a hot spot. The goal of this effort was to identify a cooling pin-fin shape and scheme that is able to push the maximum allowable heat flux as high as possible without the maximum temperature exceeding the specified limit for the given material. Conjugate heat transfer analysis was performed on each of the randomly created candidate configurations. Response surfaces based on Radial Basis Functions were coupled with a genetic algorithm to arrive at a Pareto frontier of best trade-off solutions. The Pareto optimized configuration indicates the maximum physically possible heat fluxes for specified material and constraints.

Dislocation Nucleation and Propagation During Deposition of Cubic Metal Thin Films

2001 ◽  
Vol 677 ◽  
Author(s):  
W. C. Liu ◽  
Y. X. Wang ◽  
C. H. Woo ◽  
Hanchen Huang
Keyword(s):  
Thin Films ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Three Dimensional ◽  
Thin Film Deposition ◽  
Dislocation Nucleation ◽  
Film Deposition ◽  
Film Material ◽  
Metal Thin Films ◽  
Dynamics Simulations

ABSTRACTIn this paper we present three-dimensional molecular dynamics simulations of dislocation nucleation and propagation during thin film deposition. Aiming to identify mechanisms of dislocation nucleation in polycrystalline thin films, we choose the film material to be the same as the substrate – which is stressed. Tungsten and aluminum are taken as representatives of BCC and FCC metals, respectively, in the molecular dynamics simulations. Our studies show that both glissile and sessile dislocations are nucleated during the deposition, and surface steps are preferential nucleation sites of dislocations. Further, the results indicate that dislocations nucleated on slip systems with large Schmid factors more likely survive and propagate into the film. When a glissile dislocation is nucleated, it propagates much faster horizontally than vertically into the film. The mechanisms and criteria of dislocation nucleation are essential to the implementation of the atomistic simulator ADEPT.

Ultra high-yield one-step synthesis of conductive and superhydrophobic three-dimensional mats of carbon nanofibers via full catalysis of unconstrained thin films

2014 ◽  
Vol 2 (36) ◽  
pp. 15118-15123 ◽  
Author(s):  
Efrat Shawat ◽  
Ilana Perelshtein ◽  
Andrew Westover ◽  
Cary L. Pint ◽  
Gilbert D. Nessim
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Carbon Nanofibers ◽  
Three Dimensional ◽  
High Yield ◽  
One Step

We directly synthesized large conductive and superhydrophobic 3D mats of entangled carbon nanofibers (CNFs). The mechanism is based on thin film delamination and bi-directional catalytic CNF growth.

scholarly journals Surface plasmon assisted toxic chemical NO<sub>2</sub> gas sensor by Au ∕ ZnO functional thin films

2021 ◽  
Vol 10 (2) ◽  
pp. 163-169
Author(s):  
Ravinder Gaur ◽  
Himanshu Mohan Padhy ◽  
Manikandan Elayaperumal
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Optical Properties ◽  
Surface Plasmon ◽  
Gas Sensing ◽  
Low Cost ◽  
High Sensitivity ◽  
Film Material ◽  
Hybrid Thin Film ◽  
Spr Sensor

Abstract. In this short communication, we propose a surface plasmon resonance (SPR) sensor based on a ZnO / Au hybrid thin-film material structure and experimentally investigate its sensitivity improvement. The Kretschmann-based SPR sensor utilizes ZnO thin films and nanostructures for performance enhancement. The advancement in SPR technology relies on a low-cost, high-sensitivity, and high-selectivity sensor. Metal oxide (MO) has been incorporated into the SPR sensor to be used for detection of biological and chemical compounds. ZnO as one of the metal oxides is an attractive material due to its unique physical and optical properties. Numerous techniques for fabrication and characterization of ZnO on SPR gold substrate have been studied. The mechanism for gas and biomolecule detection depends on their interaction with the ZnO surface, which is mainly attributed to the high isoelectric point of ZnO. There are several types of ZnO nanostructures which have been employed for SPR application based on the Kretschmann configuration. In the future, the thin film and nanostructures of ZnO could be a potential application for miniature design, robust, high sensitivity, and a low-cost portable type of SPR biosensor to be used for on-site testing in a real-time and label-free manner. The present work includes the application of a developed SPR setup for gas sensing at room temperature using a specially designed gas cell. The change in the optical properties of dielectric layers (ZnO) with adsorption of gases (NO2) in order to develop an optical sensor has been presented. The obtained results emphasize the applications of an SPR setup for the study of interaction of adsorbed gas molecules, with dielectrics and gas sensing.

Reliability Issues in MEMS Related to Cyclic Loading Conditions

Materials ◽  
2004 ◽  
Author(s):  
Oliver Kraft ◽  
Cynthia A. Volkert
Keyword(s):  
Thin Films ◽  
Thermal Expansion ◽  
Biaxial Tension ◽  
Film Stress ◽  
Effect Of Temperature ◽  
Maximum Temperature ◽  
Film Material ◽  
Sensors And Actuators ◽  
Metal Thin Films ◽  
Temperature Changes

Continuous and patterned metal thin films are widely used in micro-electro-mechanical systems (MEMS). Applications range from reflective coatings in micro-optics to current carrying metallization in sensors and actuators. In these applications, temperature changes of up to several 100°C may occur, and as a result of thermal mismatch between film and substrate materials, large mechanical stresses arise. For instance, gas sensors containing metal thin films are cycled to temperatures well above 300°C[1] and temperatures up to 800°C can be anticipated in the future. Fig. 1 illustrates the effect of temperature changes on the stress development in a thin film, for the case when the substrate has a smaller thermal expansion coefficient than the film. Initially, at room temperature, the metal film under biaxial tension. On heating, the film tends to expand more than the substrate and the tensile stress in the film is reduced. For small stresses, the film and substrate behave elastically, and the slope of the curve in Fig. 1 is given by ΔαEf/(1−νf) where Δα is the difference in thermal expansion coefficients, and Ef and νf are Young’s modulus and Poisson’s ratio of the film material. Above a certain stress (in this case reached at around 250°C on heating), the film begins to plastically deform. On cooling from the maximum temperature of 500°C, the film tends to contract more than the substrate and, as a result, the film stress becomes tensile. The total strain range, Δεth is given by Δεth=ΔαΔT, where ΔT is the temperature range. Thus, for the applications mentioned above, thin metal films encounter strain ranges up to 1% and will undergo both elastic and plastic deformation during use.

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