Synthesis and characterization of lead free SnCu & SnCu/SiC composite solder

Abstract

The hazardous contain in lead solders have stimulate the current researchers to develop a lead free solders with a same or superior properties. A new approach has been done by introduce a lead free composite solder with an outstanding properties than the monolithic lead free solders. In this study, the new lead free composite solder paste is developed by adding different weight percentage ( 0, 0.25, 0.50, 0.75 and 1.0 wt%) of Silicon Carbide, SiC into SnCu solder paste. The composite solder paste was prepared by mixing SnCu solder powder with flux to produce a solder in a paste form. Then, the solder paste was mixed with different weight percentage of SiC particles .The performance of composite solder paste were then analysed based on its melting point, printability, electrical resistivity, intermetallic compound (IMC) formation, wettability and the microhardness. The melting point and the electrical resistivity of SnCu composite solder paste was comparable with monolthic solder paste. Thus, the changes in conventional soldering process was not required. The printing performance of SnCu composite solder paste on Cu substrate showing better performance as the amount of SiC particles was increased. The IMC layer was found to be thinner as the amount of SiC particles was increased. The wettability of SnCu composite solder paste showing better contact angle than the monolithic SnCu solder paste with optimum contact angle of 7.579 º. The highest microhardness (10.88 HV) was achieved as 0.75 wt% of SiC particles was added. As overall, the result obtained indicate that, the addition of SiC particles could enhance the properties of solder paste.