Diamond Particles Composite Packing Materials

With the rapid development of integrated circuits, the electronic packaging materialwith excellent thermal conductivity (TC) and thermal expansion coefficient (TEC) isbadly needed. However, there exits some disadvantages in traditional electronic packagingmaterials. For example，the TC of ceramic base packaging materials is quite low, the TECof metal base packaging materials is too large and the TC of graphite base packagingmaterials in the direction perpendicular to graphitic layers is also quite low. As we allknow, diamond is a material with high TC and low TEC. Adding diamond in the matrix ofpackaging materials may improve its thermal properties. But diamond can not combinewith ceramic or metal matrix tightly, which lead to high interface thermal resistance. Inthis paper, we improved the combination of diamond and matrix by vacuum slow vapordeposition. Also the TC of graphite base composite materials in the direction perpendicul-ar to graphitic layers was increased by adding nano-diamond.Ti coated diamond particles as well as Cr coated diamond particles were prepared byvacuum slow vapor deposition process, the thicknesses of the coatings were respectively200nm and2μm. Ti coated diamond reinforced borosilicate glass composite wasfabricated by hot-press sintering. Compared with diamond/borosilicate glass composite, Ticoated diamond/borosilicate galss composite process higher bending strength, density aswell as TC, and the TEC of it match well with that of semiconductor element. When thevolume content of Ti coated diamond in the composite was30%, its bending strength was92MPa, density was0.89, TC was2.89W/(m·K) and TEC was6.16×10-6/K.Graphite base composite materials containing graphene and nano-diamond wereprepared by electrolysis. Measurements show that the TC of the graphite containinggrapheme in the direction perpendicular to graphitic layers was improved by addingnano-diamond. When the volume content of the nano-diamond was2%the TC increasedby30%.Cr coated diamond reinforced copper composite was prepared by spark plasmasintering. Compared with diamond/Cu composite, Cr coated diamond/Cu composite process higher bending strength, density as well as TC. When the volume content of Crcoated diamond in the composite was40%, its bending strength was189MPa, TEC was11.9×10-6/K, and TC was287W/(m·K). Its TC is higher than pure copper sample sinteredunder the same condition.