Dynamic Characterization of Thermal Interface Material for Electronic Cooling

2003 ◽  
Author(s):  
Rocky Shih ◽  
Cullen E. Bash
Keyword(s):  
Standardized Testing ◽  
Test System ◽  
Independent Study ◽  
Test Method ◽  
Thermal Interface Material ◽  
Thermal Interface ◽  
Automated Test ◽  
And Performance ◽  
Interface Materials

The principle of measuring thermal resistance of thermal interface material (TIM) by sandwiching the material between a hot block and cold block is well known in the industry. TIM manufacturers usually use a variation of the industrial standard ASTM D5470 test method, and subsequently provide data that is difficult for the end user to effectively utilize for product development. This paper will discuss the design and construction of an automated TIM test system based on the ASTM D5470 standard. This automated test vehicle provides an independent study of various TIMs. The instrument enables standardized testing and performance documentation of interface materials from a wide array of manufacturers making it easier for end-users to compare and select the appropriate material for various applications. The automated test method is faster and easier to use than previous methods. It requires minimal operator intervention during the test and can perform preconditioning, and non-uniform heating if required. Experimental results obtained from the instrument will be discussed.

Joint Development of a Package-Level Thermal Interface Material Test System

2009 ◽  
Author(s):  
Yanshu Susan Chen ◽  
Stanley Pecavar ◽  
Vadim Gektin
Keyword(s):  
Material Selection ◽  
Test System ◽  
Thermal Design ◽  
Test Method ◽  
Thermal Interface Material ◽  
Test Results ◽  
Performance Measurements ◽  
Thermal Interface ◽  
Application Performance ◽  
Successful Model

As the microelectronics industry continues to trend towards smaller, lighter, and higher power devices, thermal management is becoming more important than ever. Thermal interface materials (TIMs) play a crucial role in removing heat from both bare die and lidded packages. A serious challenge the industry has been facing is the lack of an agreed upon test standard that is specifically tailored for TIM thermal performance measurements between TIM suppliers and OEM customers. ASTM D 5470 is not necessarily the best gauge for TIMs in-application performance. Data generated by the OEM often differ from TIM supplier’s results, and thus can not be used confidently in thermal design. An OEM’s material selection can also prove to be unreliable when comparing data from different TIM suppliers. This paper presents a successful model that an OEM customer (Sun Microsystems) and a TIM supplier (LORD Corporation) have established for characterization of TIMs, and illustrates a package-level thermal test vehicle (TTV) setup for junction-to-sink thermal resistance measurements. Also presented are test results for several TIMs and repeatability of the test method. The effects of a few influencing factors, such as pressure load and TIM staging time, on the test results are also discussed.

Micron and Submicron-Scale Characterization of Interfaces in Thermal Interface Material Systems

2006 ◽  
Vol 128 (2) ◽  
pp. 130-136 ◽  
Author(s):  
Arun Gowda ◽  
David Esler ◽  
Sandeep Tonapi ◽  
Annita Zhong ◽  
K. Srihari ◽  
...  
Keyword(s):  
Thermal Performance ◽  
Acoustic Microscopy ◽  
Thermal Interface Material ◽  
System Level ◽  
Interfacial Behavior ◽  
Heat Spreader ◽  
Thermal Interface ◽  
Submicron Scale ◽  
Interface Materials

One of the key challenges in the thermal management of electronic packages are interfaces, such as those between the chip and heat spreader and the interface between a heat spreader and heat sink or cold plate. Typically, thermal interfaces are filled with materials such as thermal adhesives and greases. Interface materials reduce the contact resistance between the mating heat generating and heat sinking units by filling voids and grooves created by the nonsmooth surface topography of the mating surfaces, thus improving surface contact and the conduction of heat across the interface. However, micron and submicron voids and delaminations still exist at the interface between the interface material and the surfaces of the heat spreader and semiconductor device. In addition, a thermal interface material (TIM) may form a filler-depleted and resin-rich region at the interfaces. These defects, though at a small length scale, can significantly deteriorate the heat dissipation ability of a system consisting of a TIM between a heat generating surface and a heat dissipating surface. The characterization of a freestanding sample of TIM does not provide a complete understanding of its heat transfer, mechanical, and interfacial behavior. However, system-level characterization of a TIM system, which includes its freestanding behavior and its interfacial behavior, provides a more accurate understanding. While, measurement of system-level thermal resistance provides an accurate representation of the system performance of a TIM, it does not provide information regarding the physical behavior of the TIM at the interfaces. This knowledge is valuable in engineering interface materials and in developing assembly process parameters for enhanced system-level thermal performance. Characterization of an interface material between a silicon device and a metal heat spreader can be accomplished via several techniques. In this research, high-magnification radiography with computed tomography, acoustic microscopy, and scanning electron microscopy were used to characterize various TIM systems. The results of these characterization studies are presented in this paper. System-level thermal performance results are compared to physical characterization results.

scholarly journals Noncured Graphene Thermal Interface Materials for High-Power Electronics: Minimizing the Thermal Contact Resistance

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1699
Author(s):  
Sriharsha Sudhindra ◽  
Fariborz Kargar ◽  
Alexander A. Balandin
Keyword(s):  
Contact Resistance ◽  
High Power ◽  
Thermal Contact Resistance ◽  
Thermal Contact ◽  
Wide Band ◽  
Thermal Interface Material ◽  
Thermal Interface Materials ◽  
Total Thermal Resistance ◽  
Thermal Interface ◽  
Interface Materials

We report on experimental investigation of thermal contact resistance, RC, of the noncuring graphene thermal interface materials with the surfaces characterized by different degree of roughness, Sq. It is found that the thermal contact resistance depends on the graphene loading, ξ, non-monotonically, achieving its minimum at the loading fraction of ξ ~15 wt %. Decreasing the surface roughness by Sq~1 μm results in approximately the factor of ×2 decrease in the thermal contact resistance for this graphene loading. The obtained dependences of the thermal conductivity, KTIM, thermal contact resistance, RC, and the total thermal resistance of the thermal interface material layer on ξ and Sq can be utilized for optimization of the loading fraction of graphene for specific materials and roughness of the connecting surfaces. Our results are important for the thermal management of high-power-density electronics implemented with diamond and other wide-band-gap semiconductors.

Characterization of a Liquid-Metal Micro Droplets Thermal Interface Material

2010 ◽  
Author(s):  
Amer M. Hamdan ◽  
Aric R. McLanahan ◽  
Robert F. Richards ◽  
Cecilia D. Richards
Keyword(s):  
Liquid Metal ◽  
Thermal Resistance ◽  
Contact Resistance ◽  
Applied Load ◽  
Thermal Interface Material ◽  
Thermal Interface ◽  
Interface Resistance ◽  
Thermal Interface Resistance ◽  
Droplet Array

This work presents the characterization of a thermal interface material consisting of an array of mercury micro droplets deposited on a silicon die. Three arrays were tested, a 40 × 40 array (1600 grid) and two 20 × 20 arrays (400 grid). All arrays were assembled on a 4 × 4 mm2 silicon die. An experimental facility which measures the thermal resistance across the mercury array under steady state conditions is described. The thermal interface resistance of the arrays was characterized as a function of the applied load. A thermal interface resistance as low as 0.253 mm2 K W−1 was measured. A model to predict the thermal resistance of a liquid-metal micro droplet array was developed and compared to the experimental results. The model predicts the deformation of the droplet array under an applied load and then the geometry of the deformed droplets is used to predict the thermal resistance of the array. The contact resistance of the mercury arrays was estimated based on the experimental and model data. An average contact resistance was estimated to be 0.14 mm2 K W−1.

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.

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