Polymer with high thermal conductivity

Highly thermal conductive polymer composites can be obtained by using fillers with high thermal conductivity and at high percentages. Thermally conductive polymer composites find wide applications in semiconductor industry such as electronic components encapsulation, in which the heat dissipation of circuit boards becomes more and more important as silicon chips get denser and faster. Other applications of thermally conductive polymer composites... 

An approach of current interest to improve the thermal conductivity of polymers is the selective addition of nano fillers with high thermal conductivity [5]. Carbon nanotubes (CNTs) are considered to be a type of very attractive filler for the improvement of thermal transport property of polymer composites because of their extremely high thermal conductivity (about 6000 W/mK for single-walled CNTs and about 3000 W/mK for multi-walled CNTs) [2]. 

Thermally conductive adhesives may be filled with metal, ceramic, or inorganic particles. Silver-filled epoxies have high thermal conductivities, but may not be used where there is a risk of electrical shorting. In such cases, epoxies or other polymers filled with electrically resistive, but thermally conductive materials such as aluminum nitride, boron nitride, alumina, or beryllia must be used. Some applications for thermally conductive adhesives include attachment of power devices, heat sinks, large components such as capacitors and transformers, large ceramic substrates, and edge connectors. 

The main advantages of silver-glass adhesives are their very high thermal conductivities and thermal stabilities compared with filled polymer resin formulations. Thermal conductivities of 65 W/mK to over 80 W/m K are reported. ... 

Polymer-matrix composites have been used as one of the most common packaging materials for encapsulating a variety of electronic components for dissipating heat [14]. In this section, 3D AlN nanowhiskers with brush-hke structure were filled into the polymer matrix to enhance its thermal conductivity. The 3D brush-hke AlN fiUers were fabricated by CS process [7a], as iUustrated in Section 3.2. The use of AlN as a filler candidate to enhance the thermal conductivity of the polymer is attributed to its attractive properties such as high thermal conductivity, high electrical resistivity, and good chemical stabihty with polymers [1]. To explore the promoting effect of the 3D brush-hke AIN fillers on thermal conductivity, three types of AIN fillers with different brush-hke filler aspect ratio were added into polymer matrix to fabricate a series of composites and their thermal conductivities were measured. The results demonstrated that the 3D brush-hke AIN nanowhiskers fillers can effectively enhance the thermal conductivity of the polymer composite. 

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