Durability of Low Melt Alloys as Thermal Interface Materials

2015 ◽  
Author(s):  
Chandan K. Roy ◽  
Daniel K. Harris ◽  
Sushil Bhavnani ◽  
Michael C. Hamilton ◽  
Wayne Johnson ◽  
...  
Keyword(s):  
Thermal Performance ◽  
Performance Testing ◽  
Thermal Interface Material ◽  
Thermal Interface Materials ◽  
Thermal Interface ◽  
Accelerated Life ◽  
Extended Aging ◽  
Interface Materials ◽  
Substrate Alloy

This paper focuses on developing a reliable thermal interface material (TIM) using low melt alloys (LMAs) containing gallium (Ga), indium (In), bismuth (Bi), and tin (Sn). The investigation described herein involved the in situ thermal performance of the LMAs as well as performance evaluation after accelerated life cycle testing, which included isothermal aging at 130°C and thermal cycling from −40°C to 80°C. Three alloys (75.5Ga &24.5In, 100Ga, and 51In, 32.5Bi &16.5Sn) were chosen for testing the thermal performance. Testing methodologies used follow ASTM D5470 protocols and the results are compared with some commercially available TIMs. The LMAs-substrate interaction was investigated by applying the alloys using different surface treatments (copper and tungsten). Measurements show that the alloys did survive extended aging and cycling depending upon the substrate-alloy combinations.

Durability of Low Melt Alloys as Thermal Interface Materials

2016 ◽  
Vol 138 (1) ◽  
Author(s):  
Chandan K. Roy ◽  
Sushil Bhavnani ◽  
Michael C. Hamilton ◽  
R. Wayne Johnson ◽  
Roy W. Knight ◽  
...  
Keyword(s):  
Thermal Performance ◽  
Performance Testing ◽  
Thermal Interface Materials ◽  
Thermal Interface ◽  
High Performing ◽  
Accelerated Life ◽  
Significant Performance ◽  
Interface Materials ◽  
Temperature Aging

This study investigates the reliability of low melt alloys (LMAs) containing gallium (Ga), indium (In), bismuth (Bi), and tin (Sn) for the application as Thermal interface materials (TIMs). The analysis described herein involved the in situ thermal performance of the LMAs as well as performance evaluation after accelerated life cycle testing, which included high temperature aging at 130 °C and thermal cycling from −40 °C to 80 °C. Three alloys (75.5Ga & 24.5In, 100Ga, and 51In, 32.5Bi & 16.5Sn) were chosen for testing the thermal performance. Testing methodologies used follow ASTM D5470 protocols and the performance of LMAs is compared with some high-performing commercially available TIMs. Results show that LMAs can offer extremely low (<0.01 cm2 °C/W) thermal resistance compared to any commercial TIMs. The LMA–substrate interactions were explored using different surface treatments (copper and tungsten). Measurements show that depending on the substrate–alloy combinations, the proposed alloys survive 1500 hrs of aging at 130 °C and 1000 cycles from −40 °C to 80 °C without significant performance degradation. The obtained results indicate the LMAs are very efficient as TIMs.

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 Reliability Investigation of a Carbon Nanotube Array Thermal Interface Material

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2080 ◽  
Author(s):  
Andreas Nylander ◽  
Josef Hansson ◽  
Majid Kabiri Samani ◽  
Christian Chandra Darmawan ◽  
Ana Borta Boyon ◽  
...  
Keyword(s):  
Thermal Cycling ◽  
Thermal Performance ◽  
Photoelectron Spectroscopy ◽  
Thermal Contact ◽  
Thermal Interface Material ◽  
Thermal Interface Materials ◽  
Thermal Interface ◽  
Thermal Interface Resistance ◽  
Further Development ◽  
Interface Materials

As feature density increases within microelectronics, so does the dissipated power density, which puts an increased demand on thermal management. Thermal interface materials (TIMs) are used at the interface between contacting surfaces to reduce the thermal resistance, and is a critical component within many electronics systems. Arrays of carbon nanotubes (CNTs) have gained significant interest for application as TIMs, due to the high thermal conductivity, no internal thermal contact resistances and an excellent conformability. While studies show excellent thermal performance, there has to date been no investigation into the reliability of CNT array TIMs. In this study, CNT array TIMs bonded with polymer to close a Si-Cu interface were subjected to thermal cycling. Thermal interface resistance measurements showed a large degradation of the thermal performance of the interface within the first 100 cycles. More detailed thermal investigation of the interface components showed that the connection between CNTs and catalyst substrate degrades during thermal cycling even in the absence of thermal expansion mismatch, and the nature of this degradation was further analyzed using X-ray photoelectron spectroscopy. This study indicates that the reliability will be an important consideration for further development and commercialization of CNT array TIMs.

Comparative Test Data for TIM Materials for LED Applications

2012 ◽  
Vol 2012 (DPC) ◽  
pp. 000655-000683
Author(s):  
Victor Papanu
Keyword(s):  
Thermal Performance ◽  
Thermal Interface Materials ◽  
In Situ Testing ◽  
Thermal Interface ◽  
Testing Procedures ◽  
Industry Standard ◽  
Different Types ◽  
Interface Materials ◽  
Processor Module

Developments in thermal interface materials (TIMs) continue across the industry with a variety of different types of materials. Thermal and mechanical design engineers are often confronted with the need to select which type or category of TIM material is the most appropriate for a specific LED module application, which can be confusing, and how to determine which materials provide the best thermal performance. The next step is understanding which TIM material types meet requirements for ease of shipping, handling, placement, cost, and rework. These are important distinctions, in addition to thermal performance. This presentation will illustrate comparative testing results for a set of thermal interface materials (TIMs) in different categories, using different TIM testing procedures. Test data prepared using three different test methods will be compared:1. ASTM D5470-06 with known temperatures and clamping forces;2. In-situ testing with industry-standard semiconductor modules, at known temperatures and estimated clamping forces;3. In-situ testing utilizing a thermal test vehicle (TTV) for TIM2 performance for a processor module. In-situ testing has been performed at an independent power semiconductor manufacturer, using both industry-standard and commonly-available modules and a custom-designed module with a relatively small footprint, capable of high operating junction temperatures. This testing data can illustrate how different types of TIM materials perform in laboratory testing conditions, for precise comparisons on thermal performance alone; and how different types of materials perform in what are termed as “in-situ” test procedures. This term is used for application-specific conditions, where additional variables are encountered in the testing (such as non-flat surface conditions and unknown clamping force values), which is significantly different from the laboratory conditions used to generate ASTM D-5470 test values. The comparative testing that has been undertaken will be described, showing that images of various power semiconductors with several different materials tend to correlate with the thermal resistance of materials measured with the ASTM D 5470-06 method. These thermal interface materials were also tested on a TTV supplied by a major processor module. The relevance of the thermal imaging, the TTV and the ASTM values will be discussed. This presentation is intended to illustrate the differences in experimental data from one TIM material to another, as well as the differences in testing procedures.

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.

Characterizing Bulk Thermal Conductivity and Interface Contact Resistance Effects of Thermal Interface Materials in Electronic Cooling Applications

2003 ◽  
Author(s):  
Vadim Gektin ◽  
Sai Ankireddi ◽  
Jim Jones ◽  
Stan Pecavar ◽  
Paul Hundt
Keyword(s):  
Thermal Conductivity ◽  
Thermal Resistance ◽  
Contact Resistance ◽  
Thermal Performance ◽  
Electronic Cooling ◽  
Thermal Interface Materials ◽  
Thermal Interface ◽  
Interface Contact ◽  
Interface Materials ◽  
Bulk Thermal Conductivity

Thermal Interface Materials (TIMs) are used as thermally conducting media to carry away the heat dissipated by an energy source (e.g. active circuitry on a silicon die). Thermal properties of these interface materials, specified on vendor datasheets, are obtained under conditions that rarely, if at all, represent real life environment. As such, they do not accurately portray the material thermal performance during a field operation. Furthermore, a thermal engineer has no a priori knowledge of how large, in addition to the bulk thermal resistance, the interface contact resistances are, and, hence, how much each influences the cooling strategy. In view of these issues, there exists a need for these materials/interfaces to be characterized experimentally through a series of controlled tests before starting on a thermal design. In this study we present one such characterization for a candidate thermal interface material used in an electronic cooling application. In a controlled test environment, package junction-to-case, Rjc, resistance measurements were obtained for various bondline thicknesses (BLTs) of an interface material over a range of die sizes. These measurements were then curve-fitted to obtain numerical models for the measured thermal resistance for a given die size. Based on the BLT and the associated thermal resistance, the bulk thermal conductivity of the TIM and the interface contact resistance were determined, using the approach described in the paper. The results of this study permit sensitivity analyses of BLT and its effect on thermal performance for future applications, and provide the ability to extrapolate the results obtained for the given die size to a different die size. The suggested methodology presents a readily adaptable approach for the characterization of TIMs and interface/contact resistances in the industry.

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.  

Mechanical Insertion and Reliability Testing of Thermal Interface Materials for Semiconductor Test and Burn-in Applications

2018 ◽  
Vol 2018 (1) ◽  
pp. 000613-000618
Author(s):  
Dave Saums ◽  
Tim Jensen ◽  
Carol Gowans ◽  
Seth Homer ◽  
Ron Hunadi
Keyword(s):  
Thermal Performance ◽  
Mechanical Performance ◽  
Device Under Test ◽  
Thermal Interface Materials ◽  
Reliability Testing ◽  
Mechanical Reliability ◽  
Thermal Interface ◽  
Cycling Test ◽  
Semiconductor Test ◽  
Interface Materials

Abstract Semiconductor test and burn-in requirements for thermal interface materials (TIMs) are challenging, with difficult mechanical reliability requirements that are not found in other types of applications for these materials. To demonstrate the ability of certain newly-developed TIMs to not only provide suitable thermal performance for the device under test and meet these mechanical requirements, a contact cycling test has been devised in three phases for evaluating TIM mechanical performance and durability.

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