Conductivity Enhancement of Thermal Interface Material via Capillary Attraction

Author(s):  
Hongye Sun ◽  
M. M. F. Yuen

2020 ◽  
Vol 995 ◽  
pp. 15-20
Author(s):  
Ivy Ann C. Razonado ◽  
Emee Grace T. Suarnaba ◽  
Lawrence V. Madriaga ◽  
Leslie Joy L. Diaz

Nowadays, there is a need for efficiency and miniaturization in electronic products. However, in the chip level, heat dissipation can limit the performance of these gadgets. Semiconductor industries addressed this thermal management challenge by using thermal interface material. Previous studies have shown that polymer-clay nanocomposite has an enhanced thermal conductivity which can be used as a thermal interface material. In this study, the aim was to determine the effect of casting techniques on the microstructure and thermal conductivity of the polymer-clay nanocomposites. Solution intercalation method was used in fabricating the 5vol% polymer-clay nanocomposite. Organo-modified montmorillonite (MMT) was dispersed in unsaturated polyester (UP) matrix by means of high frequency ultrasonication and formed using two casting techniques; mold casting and tape casting. Results showed a slight increase in the thermal conductivity coefficient of the tape-casted samples at 2.99 W/m-K compared to the mold-casted samples at 2.87 W/m-K. Transmission electron microscopy (TEM) and x-ray diffraction (XRD) results exhibited dispersed microstructure for both casting techniques. Polymer intercalation of ~16% increase in d-spacing of clay for mold-casted samples and with a ~20% increase in d-spacing of clay for tape-casted samples were observed. With these microstructure modifications, the increase in the thermal conductivity coefficient of the tape-casted samples can be attributed to the shear force employed by the tape casting technique.





Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1699
Author(s):  
Sriharsha Sudhindra ◽  
Fariborz Kargar ◽  
Alexander A. Balandin

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.



2014 ◽  
Vol 49 (22) ◽  
pp. 7844-7854 ◽  
Author(s):  
J. Liu ◽  
U. Sahaym ◽  
I. Dutta ◽  
R. Raj ◽  
M. Renavikar ◽  
...  


2021 ◽  
pp. 002199832110595
Author(s):  
Weontae Oh ◽  
Jong-Seong Bae ◽  
Hyoung-Seok Moon

The microstructural change of graphite was studied after ultrasonic treatment of the graphite. When the graphite solution was treated with varying ultrasonic power and time, the microstructure changed gradually, and accordingly, the thermal conductivity characteristics of the composite containing the as-treated graphite was also different with each other. Thermal conductivity showed the best result in the silicone composite containing graphite prepared under the optimum condition of ultrasonic treatment, and the thermal conductivity of the composite improved proportionally along with the particle size of graphite. When the silicone composite was prepared by using a mixture of inorganic oxides and graphite rather than graphite alone, the thermal conductivity of the silicone composite was further increased. A silicone composite containing graphite was used for LED (light emitting diode) lighting system as a thermal interface material (TIM), and the temperature elevation due to heat generated, while the lighting was actually operated, was analyzed.



Author(s):  
Amer M. Hamdan ◽  
Aric R. McLanahan ◽  
Robert F. Richards ◽  
Cecilia D. Richards

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.



2019 ◽  
Vol 131 ◽  
pp. 1075-1082 ◽  
Author(s):  
Jin Cui ◽  
Jicheng Wang ◽  
Justin A. Weibel ◽  
Liang Pan


2018 ◽  
Vol 7 (4.33) ◽  
pp. 530
Author(s):  
Mazlan Mohamed ◽  
Mohd Nazri Omar ◽  
Mohamad Shaiful Ashrul Ishak ◽  
Rozyanty Rahman ◽  
Zaiazmin Y.N ◽  
...  

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.  



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