(152a) Synthesis and Applications of Low Melting Point Tin/Indium (Sn/In) Nanosolders

Many electronics manufacturing processes require low temperature processing, such as flexible electronics, electronics or devices involving thermal sensitive components, etc. To meet the requirement of low temperature processing as well as to satisfy the need for energy saving, low melting point solder particles are necessary for electronics assembly and joining of certain products. Herein we report the synthesis of tin/indium (Sn/In) alloy nanoparticles as a new nanosolder material for low temperature applications. The nanosolders are synthesized by a surfactant-assisted chemical reduction method. The parameters that affect the synthesis process such as solution pH, stirring speed and surfactant concentration are studied to control the size and shape of the Sn/In nanosolders. It is found that oxidation plays a significant role in nanosolder formation. SEM, TEM, XRD, and EDS are used to determine the structure and composition of the nanosolders. DSC test has been conducted to determine the melting points of the nanosolders with various compositions. The nanosolders have been used to join different components. Our results show that the nanosolder particle size and shape can be well controlled under optimum conditions. These low melting point nanosolders have potential for such applications as micro- or nanojoining techniques, bonding and interconnection on flexible electronics.