Laser Sintering of Copper Nanoparticles: A Simplified Model for Fluence Estimation and Validation

2017 ◽  
Author(s):  
Nilabh Roy ◽  
William Jou ◽  
He Feng ◽  
Jihoon Jeong ◽  
Yaguo Wang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Copper Nanoparticles ◽  
Integrated Circuit ◽  
Laser Sintering ◽  
Simplified Model ◽  
Flexible Substrates ◽  
Copper Nanoparticle ◽  
Pulsed Lasers ◽  
Low Resistivity ◽  
Rc Delay

Copper (Cu) has already replaced aluminum as the primary material for interconnect fabrication due to its superior electrical and thermal conductivity. Low resistivity of Cu decreases the RC delay which in turn increases the integrated circuit (IC) speed. Copper nanoparticle (NP) inks can also serve as a promising replacement of silver NP inks in 2D printing applications on solid and flexible substrates. This paper presents a simplified model to estimate optimum laser sintering parameters of Cu NPs. The model is validated by the experimental sintering results using nanosecond and femtosecond pulsed lasers. The predicted sintering thresholds agree well with sintering experiments.

A Comprehensive Study of the Sintering of Copper Nanoparticles Using Femtosecond, Nanosecond, and Continuous Wave Lasers

2017 ◽  
Vol 6 (1) ◽  
Author(s):  
Nilabh K. Roy ◽  
Obehi G. Dibua ◽  
William Jou ◽  
Feng He ◽  
Jihoon Jeong ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Continuous Wave ◽  
Laser Sintering ◽  
Simplified Model ◽  
Laser Exposure ◽  
Pulsed Lasers ◽  
Input Output ◽  
Processing Window ◽  
Low Costs ◽  
Comprehensive Study

A high electrical and thermal conductivity coupled with low costs make copper (Cu) an enticing alternative to aluminum for the fabrication of interconnects in packaging applications. To tap into the benefits of the ever-reducing size of transistors, it is required to increase the input/output pin count on electronic chips, and thus, minimize the size of chip to board interconnects. Laser sintering of Cu nanoparticle (NP) inks can serve as a promising process for developing these micron sized, 3D interconnect structures. However, the exact processing windows for Cu NP sintering are not well known. Therefore, this paper presents an extensive experimental investigation of the sintering processing window with different lasers including femtosecond (fs), nanosecond (ns), and continuous-wave (CW) lasers. The dependence of the processing window on Cu layer thicknesses and laser exposure durations has also been investigated. A simplified model to estimate optimum laser sintering windows for Cu NPs using pulsed lasers is presented and the predicted estimates are compared against the experimental results. Given the simplicity of the model, it is shown to provide good estimates for fluence required for the onset of sintering and the processing window for good sintering of Cu NPs.

Biogenic synthesis of copper nanoparticles from rose (Rosa indica L.) and their applications in photocatalytic degradation of Malachite Green and Carbol Fuchsin dyes

2020 ◽  
Vol 10 ◽  
Author(s):  
Manmeet Kaur ◽  
Suman Prajapati ◽  
Samneek Cholia ◽  
Jaskeet Singh Mann ◽  
Gurpreet Singh
Keyword(s):  
Photocatalytic Degradation ◽  
Malachite Green ◽  
Copper Nanoparticles ◽  
Dye Degradation ◽  
Industrial Effluent ◽  
Copper Nanoparticle ◽  
Synthesis Of Nanoparticles ◽  
Carbol Fuchsin ◽  
Double Beam ◽  
The Rose

Background: In the recent years, the green synthesis of nanoparticles has taken a lead role over the conventional chemical and physical approach due to its non-toxic, cost effective parameters and has found its place in various applications. Objectives: The major objectives of this study was to synthesise and characterize the copper nanoparticles using the rose extract at different set of conditions and analyse these nanoparticles as a source of dye degradation agent under sunlight conditions. Methods: Present study was conducted with the aim to synthesis the copper nanoparticle using the rose petal extract. The components present the in the extract act as the reduction and stabilization agents for the synthesis of CuNPs. The synthesized nanoparticles were characterized by using UV-VIS, FTIR, XRD and SEM analysis. Photocatalytic degradation of two dyes (Malachite Green and Carbol fuchsin) was analysed using double beam spectroscopic analysis Results: UV-Vis analysis indicated the presence of a peak at around 630 nm. The FT-IR analysis indicated the involvement of various biomolecules during the synthesis of nanoparticles. The structure and the conformation was elucidated using XRD and SEM showed the agglomerated form of the synthesized nanoparticles with the size range of about 60-90 nm. The synthesised copper nanoparticles was used for degradation of malachite green and carbol fuchsin dye using photocatalytic under sunlight irradiation. UV-Vis spectral analysis indicated that synthesised copper nanoparticle act more effective in degradation of malachite green (around 95%) whereas carbol fuchsin showed a maximum degradation by 52% therefore suggesting that CuNPs act as an efficient photo catalyst in dye degradation. Conclusion: The results obtained from this study indicates that rose extract has the potential of synthesis of copper nanoparticles which is non-toxic and convenient approach as compared to physical and chemical synthesis. These nanoparticles can be effectively employed as dye decolourization agents to treat industrial effluent and prevent the environmental pollution.

Simulation and Characterization of Nanoparticle Thermal Conductivity for a Microscale Selective Laser Sintering System

2021 ◽  
Author(s):  
Joshua Grose ◽  
Obehi G. Dibua ◽  
Dipankar Behera ◽  
Chee S. Foong ◽  
Michael Cullinan
Keyword(s):  
Thermal Conductivity ◽  
Selective Laser Sintering ◽  
Primary Source ◽  
Laser Sintering ◽  
Metal Nanoparticle ◽  
Feature Size ◽  
Cad Models ◽  
Minimum Feature Size ◽  
Geometric Arrangements ◽  
Thermal Simulations

Abstract Additive Manufacturing (AM) technologies are often restricted by the minimum feature size of parts they can repeatably build. The microscale selective laser sintering (μ-SLS) process, which is capable of producing single micron resolution parts, addresses this issue directly. However, the unwanted dissipation of heat within the powder bed of a μ-SLS device during laser sintering is a primary source of error that limits the minimum feature size of the producible parts. A particle scale thermal model is needed to characterize the thermal properties of the nanoparticles undergoing sintering and allow for the prediction of heat affected zones (HAZ) and the improvement of final part quality. Thus, this paper presents a method for the determination of the effective thermal conductivity of metal nanoparticle beds in a microscale selective laser sintering process using finite element simulations in ANSYS. CAD models of nanoparticle groups at various timesteps during sintering are developed from Phase Field Modeling (PFM) output data, and steady state thermal simulations are performed on each group. The complete simulation framework developed in this work is adaptable to particle groups of variable sizes and geometric arrangements. Results from the thermal models are used to estimate the thermal conductivity of the copper nanoparticles as a function of sintering duration.

Figure of Merit-Based Optimization Approach of Phase Change Material-based Composites for Portable Electronics Using Simplified Model

2021 ◽  
Author(s):  
Ayushman Singh ◽  
Srikanth Rangarajan ◽  
Leila Choobineh ◽  
Bahgat Sammakia
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Phase Change ◽  
Effective Thermal Conductivity ◽  
Phase Change Material ◽  
Figure Of Merit ◽  
Volume Fraction ◽  
Simplified Model ◽  
Transient Temperature ◽  
Change Material

Abstract This work presents an approach to optimally designing a composite with thermal conductivity enhancers (TCEs) infiltrated with phase change material (PCM) based on figure of merit (FOM) for thermal management of portable electronic devices. The FOM defines the balance between effective thermal conductivity and energy storage capacity. In present study, TCEs are in the form of a honeycomb structure. TCEs are often used in conjunction with PCM to enhance the conductivity of the composite medium. Under constrained composite volume, the higher volume fraction of TCEs improves the effective thermal conductivity of the composite, while it reduces the amount of latent heat storage simultaneously. The present work arrives at the optimal design of composite for electronic cooling by maximizing the FOM to resolve the stated trade-off. In this study, the total volume of the composite and the interfacial heat transfer area between the PCM and TCE are constrained for all design points. A benchmarked two-dimensional direct CFD model was employed to investigate the thermal performance of the PCM and TCE composite. Furthermore, assuming conduction-dominated heat transfer in the composite, a simplified effective numerical model that solves the single energy equation with the effective properties of the PCM and TCE has been developed. The effective thermal conductivity of the composite is obtained by minimizing the error between the transient temperature gradient of direct and simplified model by iteratively varying the effective thermal conductivity. The FOM is maximized to find the optimal volume fraction for the present design.

Thermal Conductivity Computation of Nanofluids by Equilibrium Molecular Dynamics Simulation: Nanoparticle Loading and Temperature Effect

2007 ◽  
Vol 1022 ◽  
Author(s):  
Suranjan Sarkar ◽  
R. Panneer Selvam
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Effective Thermal Conductivity ◽  
Copper Nanoparticles ◽  
Base Fluid ◽  
Liquid Argon ◽  
Dynamics Simulation ◽  
System Temperature ◽  
Solid Copper

AbstractA model nanofluid system of copper nanoparticles in argon base fluid was successfully modeled by molecular dynamics simulation. The interatomic interactions between solid copper nanoparticles, base liquid argon atoms and between solid copper and liquid argon were modeled by Lennard Jones potential with appropriate parameters. The effective thermal conductivity of the nanofluids was calculated through Green Kubo method in equilibrium molecular dynamics simulation for varying nanoparticle concentrations and for varying system temperatures. Thermal conductivity of the basefluid was also calculated for comparison. This study showed that effective thermal conductivity of nanofluids is much higher than that of the base fluid and found to increase with increased nanoparticle concentration and system temperature. Through molecular dynamics calculation of mean square displacements for basefluid, nanofluid and its components, we suggested that the increased movement of liquid atoms in the presence of nanoparticle was probable mechanism for higher thermal conductivity of nanofluids.

scholarly journals Fabrication of Natural Flake Graphite/Ceramic Composite Parts with Low Thermal Conductivity and High Strength by Selective Laser Sintering

2020 ◽  
Vol 10 (4) ◽  
pp. 1314
Author(s):  
Haihua Wu ◽  
Kui Chen ◽  
Yafeng Li ◽  
Chaoqun Ren ◽  
Yu Sun ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Ceramic Composite ◽  
Selective Laser Sintering ◽  
High Strength ◽  
Laser Sintering ◽  
Post Processing ◽  
Composite Part ◽  
Low Thermal Conductivity ◽  
Powder Composition

The 3D graphite/ceramic composite prototyping parts directly prepared by selective laser sintering (SLS) were porous, which led to poor strength and low thermal conductivity. In order to obtain low thermal conductivity and high strength, its thermal conductivity and compressive strength were adjusted by changing the mixture powder composition and adding post-processing. The result showed that the addition of silicon powder in the mixture powder could significantly improve the compressive strength and thermal conductivity. The addition of expanded graphite was beneficial to the formation of the closed pores in the matrix, which slightly reduced the compressive strength but significantly reduced the thermal conductivity. The 3D graphite/ceramic composite part showed an order of magnitude improvement in compressive strength (from 1.25 to 13.87 MPa) but relatively small change in thermal conductivity (from 1.40 to 2.12 W·m−1K−1) and density (from 0.53 to 1.13 g·cm−3) by post-processing. Reasonable mixture powder composition and post-processing were determined and realized the possibility of fabricating a 3D graphite/ceramic composite part with low thermal conductivity but high compressive strength. Furthermore, it could be used for the repeated casting of steel castings, and through the comparative analysis of casting defects, the prepared graphite/ceramic composite part was expected to replace water glass sand mold.

Enhanced thermal conductivity of welding spots by coatings cupric acetate on copper nanoparticle solders

2019 ◽  
Vol 6 (8) ◽  
pp. 085091 ◽  
Author(s):  
Dongxu Wu ◽  
Congliang Huang ◽  
Yahui Ma ◽  
Yukai Wang ◽  
Fengchao Wang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Copper Nanoparticle ◽  
Cupric Acetate ◽  
Enhanced Thermal Conductivity

Deposition of Al-Doped Zinc Oxide by Direct Pulsed Laser Recrystallization at Room Temperature on Various Substrates for Solar Cell Applications

2012 ◽  
Author(s):  
Martin Y. Zhang ◽  
Qiong Nian ◽  
Gary J. Cheng
Keyword(s):  
Thin Film ◽  
Thermal Conductivity ◽  
Solar Cell ◽  
Melting Point ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Flexible Substrates ◽  
Laser Recrystallization ◽  
Azo Thin Film

In this study, a method combining room temperature pulsed laser deposition (PLD) and direct pulsed laser recrystallization (DPLR) are introduced to deposit superior transparent conductive oxide (TCO) layer on low melting point flexible substrates. As an indispensable component of thin film solar cell, TCO layer with a higher quality will improve the overall performance of solar cells. Alumina-doped zinc oxide (AZO), as one of the most promising TCO candidates, has now been widely used in solar cells. However, to achieve optimal electrical and optical properties of AZO on low melting point flexible substrate is challenging. Recently developed direct pulsed laser recrystallization (DPLR) technique is a scalable, economic and fast process for point defects elimination and recrystallization at room temperature. It features selective processing by only heating up the TCO thin film and preserve the underlying substrate at low temperature. In this study, 250 nm AZO thin film is pre-deposited by pulsed laser deposition (PLD) on flexible and rigid substrates. Then DPLR is introduced to achieve a uniform TCO layer on low melting point flexible substrates, i.e. commercialized Kapton polyimide film and micron-thick Al-foil. Both finite element analysis (FEA) simulation and designed experiments are carried out to demonstrate that DPLR is promising in manufacturing high quality AZO layers without any damage to the underlying flexible substrates. Under appropriate experiment conditions, such as 248 nm in laser wavelength, 25 ns in laser pulse duration, 15 laser pulses at laser fluence of 25 mJ/cm2, desired temperature would result in the AZO thin film and activate the grain growth and recrystallization. Besides laser conditions, the thermal conductivity and crystallinity of the substrate serve as additional factors in the DPLR process. It is found that the substrate’s thermal conductivity correlates positively with the AZO crystal size; the substrate’s crystallinity correlates positively with the AZO film’s crystallinity. The thermal expansion of substrate would also contribute to the film tensile stress after processed by DPLR technique. The overall results indicate that DPLR technique is useful and scalable for flexible solar cell manufacturing.

Separation of Internal Strains and Lattice Distortion Caused by Oxygen Impurities in Aluminum Nitride Hot-Pressed Ceramics

1994 ◽  
Vol 38 ◽  
pp. 479-487 ◽  
Author(s):  
O. N. Grigoriev ◽  
S. M. Kushnerenko ◽  
K. A. Plotnikov ◽  
W. Kreher
Keyword(s):  
Thermal Conductivity ◽  
Aluminum Nitride ◽  
Integrated Circuit ◽  
Room Temperature ◽  
Lattice Distortion ◽  
High Thermal Conductivity ◽  
Hybrid Integrated Circuit ◽  
Oxygen Contamination ◽  
Internal Strains ◽  
Oxygen Impurities

Recently aluminum nitride (A1N) has been intensively studied as a promising material for production of hybrid integrated circuit substrates because of its high thermal conductivity, high fjexural strength, and nontoxic nature. The estimated theoretical value of its thermal conductivity at room temperature is 320 W/mK, but it is strongly degraded by the introduction of oxygen. The measured values vary from 30 to 260 W/mK, Therefore, in production of this material the reduction of oxygen contamination is of paramount importance.

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