Melt-processed P3HT and PE Polymer Nanofiber Thermal Conductivity

MRS Advances ◽  
2017 ◽  
Vol 2 (58-59) ◽  
pp. 3619-3626 ◽  
Author(s):  
Matthew K. Smith ◽  
Thomas L. Bougher ◽  
Kyriaki Kalaitzidou ◽  
Baratunde A. Cola
Keyword(s):  
Thermal Conductivity ◽  
Thermal Contact ◽  
Heat Fluxes ◽  
High Thermal Conductivity ◽  
Chain Elongation ◽  
Large Area ◽  
Thermal Interface ◽  
Molecular Weights ◽  
Polymer Nanofiber ◽  
Polarized Raman

ABSTRACT Thermal management is a growing challenge for electronics packaging because of increased heat fluxes and device miniaturization. Thermal interface materials (TIMs) are used in electronic devices to transfer heat between two adjacent surfaces. TIMs need to exhibit high thermal conductivity and must be soft to minimize thermal contact resistance. Polymers, despite their relative softness, suffer from low thermal conductivity (∼0.2 W/m-K). To overcome this challenge, we infiltrate nanoporous anodic aluminum oxide (AAO) templates with molten polymer to fabricate large area arrays of vertically aligned polymer nanofibers. Nanoscale confinement effects and flow induced chain elongation improve polymer chain alignment (measured using polarized Raman spectroscopy) and thermal conductivity (measured using the photoacoustic method) along the fiber’s long axis. Conjugated poly(3-hexylthiophene-2,5-diyl) (P3HT) and non- conjugated polyethylene (PE) of various molecular weights are explored to establish a relationship between polymer structure, nanofiber diameter, and the resulting thermal conductivity. In general, thermal conductivity improves with decreasing fiber diameter and increasing polymer molecular weight. Thermal conductivity of approximately 7 W/m-K was achieved for both the ∼200 nm diameter HDPE fibers and the 100 nm diameter P3HT fibers. These results pave the way for optimization of the processing conditions to produce high thermal conductivity fiber arrays using different polymers, which could potentially be used in thermal interface applications.

Heat Conduction in High Thermal Conductivity Networked Composite Films for Thermal Interface Materials

2011 ◽  
Author(s):  
Hafez Raeisi Fard ◽  
Kamyar Pashayi ◽  
Fengyuan Lai ◽  
Joel Plawsky ◽  
Theodorian Borca-Tasciuc
Keyword(s):  
Thermal Conductivity ◽  
Thermal Management ◽  
Thermal Contact ◽  
Composite Films ◽  
Vital Role ◽  
High Thermal Conductivity ◽  
Thermal Interface Material ◽  
Thermal Interface ◽  
Thermally Induced ◽  
Resistance Pathway

Fast and efficient exchange of thermal energy plays a vital role in the thermal management of electronic and optoelectronic devices. A critical component for thermal management is a thermal interface material (TIM) that is used to minimize the contact thermal resistance between surfaces and to provide a low resistance pathway to spread and remove heat. Ideal TIMs must pass several key requirements: 1) high thermal conductivity κ and low thermal contact resistance with the mating surfaces; 2) easy to apply with controlled thickness; 3) low temperature processing; 4) able to accommodate thermally induced mechanical stresses during on-off cycling of the device1. Particle-based composites have reasonable slurry viscosities, however their thermal conductivity are usually very low (<10 Wm−1K−1), even when high κ nanofillers are employed, due to the thermal interface resistance between nanoparticles and the polymer matrix2 or the absence of high κ pathways.

scholarly journals Thermal Properties of the Graphene Composites: Application of Thermal Interface Materials

2018 ◽  
Vol 7 (4.33) ◽  
pp. 530
Author(s):  
Mazlan Mohamed ◽  
Mohd Nazri Omar ◽  
Mohamad Shaiful Ashrul Ishak ◽  
Rozyanty Rahman ◽  
Zaiazmin Y.N ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Matrix Material ◽  
Thermal Interface Material ◽  
Thermal Interface Materials ◽  
Uniform Thickness ◽  
Thermal Interface ◽  
Interface Materials ◽  
Main Material

Epoxy mixed with others filler for thermal interface material (TIM) had been well conducted and developed. There are problem occurs when previous material were used as matrix material likes epoxy that has non-uniform thickness of thermal interface material produce, time taken for solidification and others. Thermal pad or thermal interface material using graphene as main material to overcome the existing problem and at the same time to increase thermal conductivity and thermal contact resistance. Three types of composite graphene were used for thermal interface material in this research. The sample that contain 10 wt. %, 20 wt. % and 30 wt. % of graphene was used with different contain of graphene oxide (GO).  The thermal conductivity of thermal interface material is both measured and it was found that the increase of amount of graphene used will increase the thermal conductivity of thermal interface material. The highest thermal conductivity is 12.8 W/ (mK) with 30 w. % graphene. The comparison between the present thermal interface material and other thermal interface material show that this present graphene-epoxy is an excellent thermal interface material in increasing thermal conductivity.  

Development of a Compliant Nanothermal Interface Material

2011 ◽  
Author(s):  
David Shaddock ◽  
Stanton Weaver ◽  
Ioannis Chasiotis ◽  
Binoy Shah ◽  
Dalong Zhong
Keyword(s):  
Thermal Conductivity ◽  
Thermal Resistance ◽  
Thermal Stresses ◽  
Performance Testing ◽  
High Thermal Conductivity ◽  
Thermal Interface Material ◽  
Thermal Interface Materials ◽  
Thermal Interface ◽  
Bondline Thickness ◽  
Interface Materials

The power density requirements continue to increase and the ability of thermal interface materials has not kept pace. Increasing effective thermal conductivity and reducing bondline thickness reduce thermal resistance. High thermal conductivity materials, such as solders, have been used as thermal interface materials. However, there is a limit to minimum bondline thickness in reducing resistance due to increased fatigue stress. A compliant thermal interface material is proposed that allows for thin solder bondlines using a compliant structure within the bondline to achieve thermal resistance <0.01 cm2C/W. The structure uses an array of nanosprings sandwiched between two plates of materials to match thermal expansion of their respective interface materials (ex. silicon and copper). Thin solder bondlines between these mating surfaces and high thermal conductivity of the nanospring layer results in thermal resistance of 0.01 cm2C/W. The compliance of the nanospring layer is two orders of magnitude more compliant than the solder layers so thermal stresses are carried by the nanosprings rather than the solder layers. The fabrication process and performance testing performed on the material is presented.

scholarly journals Silver Nanoparticle-Deposited Aluminum Oxide Nanoparticle as Fillers for Epoxy Composites with High Thermal Conductivity

2018 ◽  
Vol 27 (6) ◽  
pp. 096369351802700
Author(s):  
Tao Huang ◽  
Yimin Yao ◽  
Gang Zhang ◽  
Fanling Meng
Keyword(s):  
Thermal Conductivity ◽  
Aluminum Nitride ◽  
Silver Nanoparticle ◽  
Ag Nanoparticles ◽  
Thermal Contact Resistance ◽  
Epoxy Composite ◽  
Thermal Contact ◽  
High Thermal Conductivity ◽  
Epoxy Composites ◽  
Oxide Nanoparticle

With the development of polymer-filled composites, the demand of high thermal conductivity materials is much attractive than ever. However, the process of a common method to improve thermal conductivity of composites is considerably complicated. The aim of this study is to investigate thermal conductivity of epoxy filled silver nanoparticle deposited aluminum nitride nanoparticles with relatively convenient process. We found that the thermal conductivities of composites filled with AlN/Ag nanoparticles are effectively enhanced, which is enormously increased from 0.48 Wm-1K-1(1.88 vol%) to 3.66 Wm-1K-1 (19.54 vol%). This can be ascribed to the bridging connections of silver nanoparticle among aluminum nitride nanoparticles. In addition, the thermal contact resistance of the epoxy composites filler with AlN/Ag nanoparticles is decreased, which is proved by the fitting measured thermal conductivity of epoxy composite with one physical model. We believe the finding has great potential for any microelectronic application.

A thermal interface material based on foam-templated three-dimensional hierarchical porous boron nitride

2018 ◽  
Vol 6 (36) ◽  
pp. 17540-17547 ◽  
Author(s):  
Zhilin Tian ◽  
Jiajia Sun ◽  
Shaogang Wang ◽  
Xiaoliang Zeng ◽  
Shuang Zhou ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Boron Nitride ◽  
Three Dimensional ◽  
High Thermal Conductivity ◽  
Thermal Interface Material ◽  
Thermal Interface ◽  
Hierarchical Porous ◽  
Templated Method

A high thermal conductivity boron nitride based thermal interface material was developed by a foam-templated method.

Development of a Metal Micro-Textured Thermal Interface Material

2009 ◽  
Author(s):  
R. Kempers ◽  
R. Frizzell ◽  
A. Lyons ◽  
A. J. Robinson
Keyword(s):  
Thermal Conductivity ◽  
Applied Pressure ◽  
Solid Particles ◽  
High Thermal Conductivity ◽  
Thermal Interface Material ◽  
Filler Materials ◽  
Mechanical And Thermal Properties ◽  
Metal Foil ◽  
Thermal Interface ◽  
Thermally Conductive

Typical thermal interface materials (TIMs) consist of high thermal conductivity solid particles dispersed in a continuous, low thermal conductivity organic compound. Despite using filler materials of very high thermal conductivity, the effective thermal conductivity of these TIMs is often two orders of magnitude lower than the pure filler materials. In addition, dispensing and flow of the particle-matrix composite results in voids being trapped within the bond. To address these issues, a novel metal micro-textured thermal interface material (MMT-TIM) has been developed. This material consists of a thin metal foil with raised micro-scale features that plastically deform under an applied pressure thereby creating a continuous, thermally conductive, path between the mating surfaces. Numerical tools have been developed that couple the mechanical and thermal properties and behaviour of MMT-TIMs as they undergo large-plastic deformation during assembly. This study presents the modelling approach and predictions of MMT-TIM performance based on these numerical techniques. The predictions show good agreement with experimental results, which were obtained using prototype MMT-TIMs and an advanced TIM characterization facility. Finally, a future outlook for this technology is presented based on these promising initial results.

Effect of Fe on the Microstructure and the Thermal Storage Performances of High-Silicon Aluminum Alloy

2014 ◽  
Vol 915-916 ◽  
pp. 775-779
Author(s):  
Xiao Song Li ◽  
An Hui Cai ◽  
Ji Jie Zeng
Keyword(s):  
Thermal Conductivity ◽  
Expansion Coefficient ◽  
Surface Defect ◽  
Primary Silicon ◽  
High Thermal Conductivity ◽  
Large Area ◽  
Performance Impact ◽  
Storage Performance ◽  
Low Thermal Expansion ◽  
Silicon Sheet

The influence of Fe on microstructure and the expansion coefficient and thermal conductivity of Al-30 wt.% Si alloy was studied. Results show that the primary silicon morphology and size changed significantly after joining the Fe, by angular blocky primary silicon sheet or plate into small pieces and then into a polygonal large lump, edge and angle are passivated. As the content of Fe is 0.3 wt.%, material expansion coefficient and high thermal conductivity. Later, with the increase of the content of Fe, alloy point defect and line defect, surface defect and large area defect increase, the thermal conductivity of materials and inflation performance declined. When the content of Fe is 0.1 wt.%, materials with high thermal conductivity and low thermal expansion coefficient, the heat storage performance impact is minimal.

Surface Chemistry and Characteristics Based Model for the Thermal Contact Resistance of Fluidic Interstitial Thermal Interface Materials

2001 ◽  
Vol 123 (5) ◽  
pp. 969-975 ◽  
Author(s):  
Ravi S. Prasher
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Thermal Interface Materials ◽  
Heat Spreader ◽  
Thermal Interface ◽  
Thermal Solution ◽  
Interface Materials

Microprocessor powers are increasing at a phenomenal rate, which requires very small thermal resistance between the die (chip) and the ambient, if the current economical methods of conduction and convection cooling are to be utilized. A typical thermal solution in flip chip technology utilizes two levels of thermal interface materials: between the die and the heat spreader, and between the heat spreader and the heat sink. Phase change materials and thermal greases are among the most prominent interstitial thermal interface materials (TIM) used in electronic packaging. These TIMs are typically polymeric matrix loaded with highly conducting filler particles. The dwindling thermal budget has necessitated a better understanding of the thermal resistance of each component of the thermal solution. Thermal conductivity of these particle-laden materials is better understood than their contact resistance. A careful review of the literature reveals the lack of analytical models for the prediction of contact resistance of these types of interstitial materials, which possess fluidic properties. This paper introduces an analytical model for the thermal contact resistance of these types of interstitial materials. This model is compared with the experimental data obtained on the contact resistance of these TIMs. The model, which depends on parameters such as, surface tension, contact angle, thermal conductivity, roughness and pressure matches very well with the experimental data at low pressures and is still within the error bars at higher pressures.

Simple Measuring Method of Thermal Conductivity of Silicone Grease and Effect of Carbon Nanomaterials on Its Thermal Conductivity

2007 ◽  
Author(s):  
Toshio Tomimura ◽  
Seiji Nomura ◽  
Masaaki Okuyama
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanomaterials ◽  
Cooling System ◽  
Thermal Contact ◽  
Conductivity Measurement ◽  
Measuring Method ◽  
Heat Fluxes ◽  
Quantitative Relation ◽  
Silicone Grease ◽  
Simple Method

In the electronic equipment like personal computers with high heat fluxes for instance, the thermal contact resistance plays an important role in its cooling system. To attain high cooling performance, some kind of grease is often introduced between a heat source and a heat sink. In the present study, a simple method for thermal conductivity measurement of grease has been proposed and confirmed its validity by using greases with known thermal conductivity. From a series of measurements, the validity of the present measuring method has been confirmed. Further, the effect of the addition of carbon nanomaterials on the thermal conductivity of silicone grease has been investigated, and its quantitative relation has been clarified.

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