Mechanical Behavior of Sintered Nano-sized Ag Particles (Mate2013特集号 : ｢エレクトロニクスにおけるマイクロ接合・実装技術｣シンポジウム)

The operating temperature of power devices including next generation IGBTs (Insulated Gate Bipolar Transistors) has been predicted to become higher than 473K . For this reason, for die bonding, in place of traditional Pb rich solder alloys with high melting points, attention is now being focused on sintered nanosized Ag particles having the properties of high thermostability with high thermal conductivity and of allowing low temperature joining . Only few studies, however, have been conducted in detail so far on mechanical reliability of sintered nanosized Ag particles that have complex structures with numerous microscopic pores and many of their particulars are still left unexplained. Under the condition, detailed investigations are desired on mechanical reliability including the elucidation of deformation mechanisms toward the practical use of sintered nano-sized Ag particles. Recently, the author, et al. had made close investigations of mechanical properties of sintered nano-sized Ag particles and observed an interesting behaivor that was regarded as creep deformation at ambient temperature lower than 0.4Tm (Tm is melting temperature), at which usually creep starts to take place in metals. The emergence of creep behaivor at such lower temperatures is of significance from the viewpoint of mechanical reliability analysis. Since this behaivor is considered