Fabrication and characterization copper/diamond composites for heat sink application using powder metallurgy

Zeinab Abdel Hamid, Sayed F. Moustafa, Fatma A. Morsy, Nevien Abdel Atty khalifa, Fatma Abdel Mouez

.

DOI: 10.4236/ns.2011.311120                

Abstract

Copper composites reinforced with diamond particles were fabricated by the powder metallurgical technique. Copper matrix and diamond powders were mixed mechanically, cold com- pacted at 100 bar then sintered at 900?C. The prepared powders and sintered copper/diamond composites were investigated using X-ray diffraction (XRD) and scanning electron microscope equipped with an energy dispersive X-ray analysis (SEM/EDS). The effect of diamond contents in the Cu/diamond composite on the different properties of the composite was studied. On fracture surfaces of the Cu/uncoated diamond composites, it was found that there is a very weak bonding between diamonds and pure copper matrix. In order to improve the bonding strength between copper and the reinforcement, diamond particles were electroless coated with NiWB alloy. The results show that coated diamond particles distribute uniformly in copper composite and the interface between diamond particles and Cu matrix is clear and well bonded due to the formation of a thin layer from WB2, Ni3B, and BC2 between Cu and diamond interfaces. The properties of the composites materials using coated powder, such as hardness, transverse rupture strength, thermal conductivity, and coefficient of thermal expansion (CTE) were exhibit greater values than that of the composites using uncoated diamond powder. Additionally, the results reveals that the maximum diamond incorporation was attained at 20 Vf%. Actually, Cu/20 Vf% coated diamond com- posite yields a high thermal conductivity of 430 W/mK along with a low coefficient of thermal expansion (CTE) 6 × 10–6/K.

Keywords

Powder Metallurgy; Ceramic-Matrix Composites (CMCs); Ceramics; Coating; Electroless

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Ellsworth, M.J. (2004) Chip power density and module cool technology projections for the current decade. Pro- ceedings of the 9th Intersociety Conference on Thermal and Thermo Mechanical Phenomena in Electronic Systems, Las Vegas, 2, 707-708.
[2]	Zweben, C. (1998) Advances in composite materials for thermal management in electronic packaging. Journal of Management, 50, 47-51.
[3]	Zweben, C. (2001) Thermal management and electronic packaging applications. ASM Handbook, 21, 1078-1084.
[4]	German, R.M., Hens, K.F. and Johnson, J.L. (1994) Powder metallurgy processing of thermal management materials for microelectronic applications. International Journal of Powder Metallurgy, 30, 205-215.
[5]	Evans, T.C. (1998) Thermal properties of electronic ma- terials. Thermal Management Handbook for Electronic Assemblies, McGraw-Hill, New York.
[6]	Ruch, P.W., Beffort, O., Kleiner, S., Weber, L. and Uggowitzer, P.J. (2006) Selective interfacial bonding in Al(Si)-diamond composites and its effect on thermal conductivity. Composites Science and Technology, 66, 2677-2685. doi:10.1016/j.compscitech.2006.03.016
[7]	Clyne T.W. (2000) Thermal and electrical conduction in MMCs. In: Kelly, A., Chou, T.W., Talreja, R., Clyne, T.W., Warren, R., Carlsson, L., et al., Eds., Comprehensive Composite Materials. Metal-Matrix Composites, Elsevier, Amsterdam, 3.
[8]	Weber, L. and Tavangar, R. (2007) On the Influence of active element content on the thermal conductivity and thermal expansion of Cu–X (X = Cr, B) diamond composites. Journal of Materials Science, 57, 988-991.
[9]	Schubert, T., Ciupinski, ?., Zielinski ,W., Michalski, A., Weig?rber, T. and Kieback, B. (2008) Interfacial charac- terization of Cu/diamond composites prepared by powder metallurgy for heat sink application. Scripta Materialia, 58, 263-266. doi:10.1016/j.scriptamat.2007.10.011
[10]	Schubert, T.H., Ciupiński, ?., Morgiel, J., Weidmüller, H., Weissg?rber, T. and Kieback, B. (2007) Advanced composite materials for heat sink applications. Euro PM 2007 —PM Functional Materials, Toulouse, 15-17 October 2007.
[11]	Lowenheim, F.A. (1974) Modern electroplating. John Wiley and Sons, New York.
[12]	Metal Powder Industries Federation, Princeton (1998).
[13]	Fang, Z. and Eason, J.W., (1993) Nondestructive evalua- tion of WC-Co composites using magnetic properties. International Journal of Powder Metallurgy, 29, 259- 265.
[14]	Deborah, C.D.L. (2001) Applied materials science applica- tion of engineering materials in structural, electronics, thermal and other industries. Chapman and Hall, London.
[15]	Moustafa, S.F., Abdel, H.Z., Osama, B.G. and Hussien, A. Synthesis of WC hard materials using coated powders. Advanced Powder Metall, 22, 596-601.
[16]	Saito, T., Sato, E., Matsuoka, M. and Iwakura, C.J., (1998) Electroless deposition of Ni-B, Co-B and N-Co-B alloys using dimethyl amineborane as a reducing agent. Applied Electrochemistry, 28, 559-563. doi:10.1023/A:1003233715362
[17]	Osaka ,T. Takano, N., Kurokawa, T., Kaneko, T. and Ueno, K. (2003) Characterization of chemically-depo- sited NiB and NiWB thin films as a capping layer for ULSI application. Surface and Coatings Technology, 169-170, 124-127. doi:10.1016/S0257-8972(03)00186-5
[18]	Duhin, A., Sverdlov, Y., Feldman, Y. and Shacham-Dia- mand, Y. (2009) Electroless deposition of NiWB alloy on p-type Si(100) for NiSi contact metallization. Electro- chimica Acta, 54, 6036-6041. doi:10.1016/j.electacta.2009.01.062
[19]	Mallory, G.O. (1971) The electroless nickel plating bath: effect of variables on the process. Plating, 58, 319-322.
[20]	Mallory, G.O. and Hadju, J.B. (1991) Electroless plating: Fundamentals and applications. AESF, Orlando.
[21]	Abdel, A.A., Barakat, H., Abdel, H.Z. (2008) Synthesis and characterization of electroless deposited Co–W–P thin films as diffusion barrier layer. Surface & Coatings Technology, 202, 4591-4597. doi:10.1016/j.surfcoat.2008.03.023
[22]	Pearlstein, F. and Weightman, R.F. (1974) Electroless cobalt deposition from acid baths. Journal of The Electrochemical Society, 121, 1023-1028. doi.org/10.1149/1.2401971
[23]	Ellis, D.L. and McDanels, D.L. (1993) Thermal Conduc- tivity and thermal expansion of graphite fiber- reinforced copper matrix composites. Metallurgical and Materials Transactions A, 24, 43-52. doi:10.1007/BF02669601
[24]	Abdel, G. and El-Kad, O. (2005) Improvement of wettability of carbon fiber by in-situ carbide coating. Ph.D. Thesis, Cairo University, Cairo.
[25]	Khattab, N.M.M. (2001) Ph.D. Thesis, Department of Chemistry, Faculty of Girls, Ain Shams University, Cairo.