SBIR-STTR Award

This SBIR represents a basic core technology required to design and fabricate enhanced heatsinks for the thermal management of electronics. The addition of boron nitride (BN) powder to a high thermal conductivity pitch carbon fiber laminate dramatically increases the transverse thermal conductivity. In the past the usefulness of pitch carbon fiber laminates has been limited by the low transverse conductivity. The increase in conductivity will dramatically increase the number of applications where this composite can be used for example: heatsinks, thermal radiators and missile structures. It is predicted that high thermal conductivity laminates will be able to replace structures that have traditionally been fabricated from aluminum beryllium for lower cost and weight. Prior experimentation carried out with EPSCoR funding has shown that thermal conductivity increases as the concentration of BN is increased, but also the strength of the laminate decreases. The technical objective of this project is to fabricate laminates with increasing concentrations of BN and measure the thermal conductivity and corresponding strength and stiffness. Data and design tables will be produced to enable engineers to accurately predict the performance of structures where the thermal conductivity of a pitch laminate has been enhanced by the addition of BN. Anticipated Benefits and

Potential Commercial Applications:
The technology described in this proposal has direct application to the thermal management of military and commercial electronics.

Pitch based carbon fiber laminates have very high in-plane thermal conductivity (Kx & Ky) but performance was limited by the poor thermal conductivity through the thickness, Kz.. In Phase I, XC Associates demonstrated that the addition of boron nitride powder to a pitch fiber laminate increased, Kz, by a factor of 4 compared to an unfilled laminate. This is an important result that significantly increases the thermal efficiency of lightweight composite heat sinks for avionics and space applications. Additionally the technology has important applications for other composite components such as missile fins where the increased Kz results in lower operating temperatures that directly translate into significant cost saving. This Phase II effort will build on the results of Phase I to optimize the technology and go forward to qualify composite heat sinks for avionics, space and missile applications. During the Phase II, XC Associates will design and fabricate prototype components that will then be qualified by the users at their own expense. once the prototypes are qualified this will lead to direct sales for these particular programs. The technology has direct application for thermal management in commercial and military applications. Qualification of this technology into specific applications will demonstrate that the technology represents a low risk cost effective method to enhance the thermal performance of composite structures and will lead to further commercialization opportunities.

Keywords:
Enhanced Thermal Management, Composite Structures, Organic Matrix Composites, Heat Sinks, Electronic