Citation
(2009), "Applied Nanotech (APNT) showcases a unique heat sink material known as CarbAl(™) composite", Microelectronics International, Vol. 26 No. 1. https://doi.org/10.1108/mi.2009.21826aad.009
Publisher
:Emerald Group Publishing Limited
Copyright © 2009, Emerald Group Publishing Limited
Applied Nanotech (APNT) showcases a unique heat sink material known as CarbAl(™) composite
Article Type: New products From: Microelectronics International, Volume 26, Issue 1
Technical summary of CarbAl™ material
CarbAl™ material is a carbon-based metal nanocomposite (CAl™) comprised of 80 percent carbonaceous matrix and a dispersed metal component of 20 percent aluminum.
The carbonaceous material is comprised of an isotropic thermally conductive carbonaceous matrix and additional anisotropic thermally conductive carbonaceous matter. The combination of the two carbonaceous phases achieves partial directionality whereby the heat is diffused in a preferred direction.
The thermal conductivity formula is:
whereby: α – thermal diffusion coefficient (cm2/s); cp – specific heat (J/g/K); ρ – specific gravity; ΔT – temperature gradient; Λ – thermal conductivity (W/mK).
The high cp may contribute to a large thermal conductivity yet expresses the potential of a large heat storage capacity that may be detrimental for heat sink applications. A large thermal diffusion coefficient will allow rapid diffusion of heat from the point of creation to a dissipative heat sink.
The new highly heat transmissive CarbAl™ material can be provided in rectangular blocks and other shapes based on form factor requirements of an application. The material is not hard and can be sliced easily to very thin samples that interface between the local point of heat creation and a heat sink or other heat dissipative device.
In Table I, the properties of the CarbAl™ composite are compared with silicon carbide – aluminum composites, aluminum and copper. Observe the extremely high value of the thermal diffusion coefficient of the CarbAl™ composite and the comparative value of the thermal conductivity.
In the following example of how CarbAl™ material can be used, substrate A is comprised of the CarbAl™ carbon-based metal composite material that is joined to a ceramic insulating surface B via an adhesive layer C. The adhesive layer can be a synthetic resin, solder, metal-brazing material, etc. Circuit elements and other parts (D) are placed on the ceramic insulating substrate. In other applications the ceramic insulating material can be replaced by any type of substrate or insulating film that has the circuits and parts such as semiconductor elements, resistors, condensers, etc. distributed on it (Figure 3).
Figure 3
Dr Zvi Yaniv, ANI President and CEO, noted, “nanoTX USA provides an opportunity for us to present our revolutionary high thermal diffusive materials that may provide solutions to the needs of the microelectronic industry for low cost high quality heat sink material. This new material is lighter than traditional metallic heat sinks while being three times more effective at diffusing heat” (Table I).
The new CarbAl(™) heat sink material is a nanocomposite of a carbonaceous type of material and aluminum. The aluminum content is only 20 percent, while the thermal transmission of the new material is approaching 500 W/mK (for comparison aluminium thermal conductivity is 203 and copper is 390). A technical summary of the CarbAl material can be found at: www.appliednanotech.net/TechnologyPlatforms/materials/CarbAl.as