[Zurück]

E. Neubauer, G. Korb, C. Eisenmenger-Sittner, H. Bangert, S. Chotikaprakhan, D. Dietzel, A.M. Mansanares, B.K. Bein:
"THE INFLUENCE OF MECHANICAL ADHESION OF COPPER COATINGS ON CARBON SURFACES ON THE INTERFACIAL THERMAL CONTACT RESISTANCE";
Poster: 12th International Conference on thin Films, Bratislava, Slovakia; 15.09.2002 - 20.09.2002.

THE INFLUENCE OF MECHANICAL ADHESION OF COPPER COATINGS ON CARBON SURFACES ON THE INTERFACIAL THERMAL CONTACT RESISTANCE

E.Neubauer1/2·, G. Korb1, C.Eisenmenger-Sittner2, H.Bangert2
S.Chotikaprakhan3, D.Dietzel3, A.M.Mansanares3, B.K.Bein3

* ARC Seibersdorf Research GmbH, Dept. Materials and Production Engineering
**Vienna University of Technology, Institute of Solid State Physics - Thin Film Group
*** Ruhr Universität Bochum, Exp.Phys.III, Solid State Spectroscopy Group

Metal matrix composites based on copper reinforced with carbon fibers are expected to have a high thermal conductivity and a low Coefficient of Thermal Expansion (CTE). Nevertheless due to a weak interface between copper and carbon fibers which is related to the absence of any reactivity or dissolution between the constitutents, a ?thermal gap? at the interface limits the use of this material for thermal management applications.
In order to optimise the thermal as well as the mechanical interface of this material combination, investigations were started on a simplified plane model system, consisting of a copper coating deposited by PVD on a glassy carbon surface. Starting with different cleaning procedures of the substrate, the influence on the mechanical adhesion strength of the copper coating was investigated by a pull-off method. In addition to the surface treatment, the influence of an intermediate layer on the adhesion strength was investigated.
Parallel to the investigation of the adhesion strength, the thermal contact resistance at the interface was determined using a photothermal method of characterisation, which is based on modulated Argon ion laser beam heating of the coating, leading to periodical thermal waves which propagate across the coating and the interface. At the interface reflection occurs, and from the amplitude and phase shift of the thermal wave response, measured by contactless IR radiometry at the surface of the heated coating, a quantitative description of the interfacial thermal resistance is obtained. It was shown that this method is a suitable tool to characterise thermal interfaces of 1µm copper layers on a glassy carbon surface having different mechanical adhesion strength. A good correlation between the thermal and mechanical interface was found.