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.

Characterization of Thermal Contact Resistance in Metal Micro-Textured Thermal Interface Materials Using Electrical Contact Resistance Measurements

2010 ◽  
Vol 297-301 ◽  
pp. 1190-1198 ◽  
Author(s):  
R. Kempers ◽  
A.J. Robinson ◽  
A. Lyons
Keyword(s):  
Contact Resistance ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Electrical Contact ◽  
Applied Pressure ◽  
Thermal Interface Material ◽  
Metal Foil ◽  
Electrical Contact Resistance ◽  
Thermal Interface ◽  
Thermally Conductive

A novel Metal Micro-Textured Thermal Interface Material (MMT-TIM) has been developed to address a number of shortcomings in conventional TIMs. 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. One of the difficulties in experimentally characterizing MMT-TIMs however, is distinguishing the bulk thermal resistance of the MMT-TIM from the thermal contact resistance that exists where it contacts the test apparatus. Since these materials are highly electrically conductive, this study attempts to employ electrical contact resistance measurements to estimate their thermal contact resistance. Tests using flat silver and gold specimens of known bulk thermal conductivity were used to develop a correlation between electrical and thermal contact resistance. This relationship was then employed to estimate the thermal contact resistance of a prototype silver MMT-TIM and indicates the thermal contact resistance accounts for approximately 10% of the measured thermal contact resistance. A number of issues related to this technique are discussed as well as its future outlook.

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.

Development of High Thermally Conductive Die Attach for TIM Applications

2019 ◽  
Vol 2019 (1) ◽  
pp. 000312-000315
Author(s):  
Maciej Patelka ◽  
Sho Ikeda ◽  
Koji Sasaki ◽  
Hiroki Myodo ◽  
Nortisuka Mizumura
Keyword(s):  
Thermal Conductivity ◽  
High Power ◽  
Thermal Interface Material ◽  
Thermal Interface ◽  
Power Semiconductor ◽  
Die Attach ◽  
Industry Standards ◽  
Thermally Conductive ◽  
Low Modulus ◽  
Thermal Grease

Abstract High power semiconductor applications require a Thermal Interface Die Attach Material with high thermal conductivity to efficiently release the heat generated from these devices. Current Thermal Interface Material solutions such as thermal grease, thermal pads and silicones have been industry standards, however may fall short in performance for high temperature or high-power applications. This presentation will focus on development of a cutting-edge Die Attach Solution for Thermal Interface Management, focusing on Fusion Type epoxy-based Ag adhesive with an extremally low Storage Modulus and the Thermal Conductivity reaching up to 30W/mK, and also Very Low Modulus, Low-Temperature Pressureless Sintered Silver Die Attach with the Thermal Conductivity of 70W/mK.

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.

Thermal Interface Materials From Vertically Aligned Polymer Nanotube Arrays

2013 ◽  
Author(s):  
Thomas L. Bougher ◽  
Virendra Singh ◽  
Baratunde A. Cola
Keyword(s):  
Thermal Conductivity ◽  
Amorphous Polymer ◽  
Quartz Substrate ◽  
Applied Pressure ◽  
Thermal Interface Material ◽  
Bonding Pressure ◽  
Thermal Interface ◽  
Vertically Aligned ◽  
Conductive Fillers ◽  
Enhanced Thermal Conductivity

A number of studies have reported enhancing the thermal conductivity of semi-crystalline polymers through mechanical stretching, but practical application of this process has proven difficult. Here we demonstrate the application of enhanced thermal conductivity in a purely amorphous polymer for a thermal interface material (TIM) without conductive fillers. Many polymer-based TIMs contain carbon fillers to enhance the thermal conductivity, however the TIMs reported herein are comprised solely of polymer nanotubes. The conjugated polymer polythiophene (Pth) is electropolymerized in nanotemplates to produce arrays of vertically aligned nanotubes, which adhere well to opposing substrates through van der Waals forces. We find that the total thermal resistances of the Pth-TIMs are a strong function of height with some dependence on bonding pressure, yet independent of applied pressure after bonding. Photoacoustic measurements show that the total thermal resistance of the TIMs ranges from 9.8 ± 3.8 to 155 ± 32 mm2-K/W depending on the array height and bonding pressure. Estimates of the component resistances indicate that the majority of the resistance is in the contact between the nanotube free tips and the opposing quartz substrate. These Pth-TIMs demonstrate that enhanced thermal conductivity polymers can be suitable for heat transfer materials without thermally conductive fillers.

Verbesserte Wärmeableitung sorgt für kühlere Motorventile

Konstruktion ◽  
2017 ◽  
Vol 69 (11-12) ◽  
pp. IW8-IW9
Keyword(s):  
Thermal Conductivity ◽  
High Thermal Conductivity ◽  
Thermal Interface Material ◽  
Thermal Interface ◽  
Eine Verbesserte

Auf der IAA 2017 in Frankfurt stellte Federal-Mogul Powertrain neue Werkstoffe für Ventilsitze und -führungen mit verbesserter Wärmeableitung vor (Bild 1). Die serienreifen Materialien High Thermal Conductivity (HTC) und die Beschichtung mit Thermal Interface Material (TIM) können die Temperaturen am Ventilteller um bis zu 70 °C reduzieren. Dies ermöglicht eine verbesserte Verbrennung und niedrigere Emissionen.

scholarly journals An Integrated Approach to Design and Develop High-Performance Polymer-Composite Thermal Interface Material

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 807
Author(s):  
Syed Sohail Akhtar
Keyword(s):  
Thermal Conductivity ◽  
Aspect Ratio ◽  
High Performance ◽  
High Thermal Conductivity ◽  
Thermal Interface Material ◽  
Design Stage ◽  
Filler Concentration ◽  
Melt Mixing ◽  
Thermal Interface ◽  
Wide Range

A computational framework based on novel differential effective medium approximation and mean-field homogenization is used to design high-performance filler-laden polymer thermal interface materials (TIMs). The proposed design strategy has the capability to handle non-dilute filler concentration in the polymer matrix. The effective thermal conductivity of intended thermal interface composites can be tailored in a wide range by varying filler attributes such as size, aspect ratio, orientation, as well as filler–matrix interface with an upper limit imposed by the shear modulus. Serval potential polymers and fillers are considered at the design stage. High-density polyethylene (HDPE) and thermoplastic polyurethane (TPU) with a non-dilute concentration (~60 vol%) of ceramic fillers exhibit high thermal conductivity (4–5 W m−1 K−1) without compromising the high compliance of TIMs. The predicted thermal conductivity and coefficient of thermal expansion are in excellent agreement with measured data of various binary composite systems considering HDPE, TPU, and polypropylene (PP) loaded with Al2O3 and AlN fillers in varying sizes, shapes, and concentrations, prepared via the melt-mixing and compression-molding route. The model also validates that manipulating filler alignment and aspect ratio can significantly contribute to making heat-conducting networks in composites, which results in ultra-high thermal conductivity.

scholarly journals Innocuous, Highly Conductive, and Affordable Thermal Interface Material with Copper-Based Multi-Dimensional Filler Design

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 132
Author(s):  
Woochang Kim ◽  
Chihyun Kim ◽  
Wonseok Lee ◽  
Jinsung Park ◽  
Duckjong Kim
Keyword(s):  
Thermal Conductivity ◽  
Low Cost ◽  
Three Dimensional ◽  
Precursor Solution ◽  
High Thermal Conductivity ◽  
Thermal Interface Material ◽  
Interfacial Thermal Resistance ◽  
Thermal Interface ◽  
Wetting Properties ◽  
Earth Abundant

Thermal interface materials (TIMs), typically composed of a polymer matrix with good wetting properties and thermally conductive fillers, are applied to the interfaces of mating components to reduce the interfacial thermal resistance. As a filler material, silver has been extensively studied because of its high intrinsic thermal conductivity. However, the high cost of silver and its toxicity has hindered the wide application of silver-based TIMs. Copper is an earth-abundant element and essential micronutrient for humans. In this paper, we present a copper-based multi-dimensional filler composed of three-dimensional microscale copper flakes, one-dimensional multi-walled carbon nanotubes (MWCNTs), and zero-dimensional copper nanoparticles (Cu NPs) to create a safe and low-cost TIM with a high thermal conductivity. Cu NPs synthesized by microwave irradiation of a precursor solution were bound to MWCNTs and mixed with copper flakes and polyimide matrix to obtain a TIM paste, which was stable even in a high-temperature environment. The cross-plane thermal conductivity of the copper-based TIM was 36 W/m/K. Owing to its high thermal conductivity and low cost, the copper-based TIM could be an industrially useful heat-dissipating material in the future.

scholarly journals Development of High Thermally Conductive Die Attach for TIM Applications

2020 ◽  
Vol 17 (3) ◽  
pp. 106-109
Author(s):  
Maciej Patelka ◽  
Sho Ikeda ◽  
Koji Sasaki ◽  
Hiroki Myodo ◽  
Nortisuka Mizumura
Keyword(s):  
Thermal Conductivity ◽  
High Power ◽  
Thermal Interface Material ◽  
Thermal Interface ◽  
Power Semiconductor ◽  
Die Attach ◽  
Industry Standards ◽  
Thermally Conductive ◽  
Low Modulus ◽  
Thermal Grease

Abstract High-power semiconductor applications require a thermal interface die attach material with high thermal conductivity to efficiently release the heat generated from these devices. Current thermal interface material solutions such as thermal grease, thermal pads, and silicones have been industry standards, however may fall short in performance for high-temperature or high-power applications. This article focuses on development of a cutting-edge die attach solution for thermal interface management, focusing on fusion-type epoxy-based Ag adhesive with an extremely low storage modulus and the thermal conductivity reaching up to 30 W/mK, and also very low-modulus, low-temperature pressureless sintering silver die attach with a thermal conductivity of 70 W/mK.

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