אינדקס חברות וספקים
: יאיר רוזנטל, מכללת אפקה
The electronics industries across the world are replacing lead-tin eutectic solders with lead-free solders. The most common lead-free solder alloys include Sn–0.7Cu, Sn–3.5Ag, and Sn–3.8Ag– 0.7Cu (in wt. % with slight variations in composition). Although a considerable amount of information on Pb-free solders has been published in the last few years, there is a need for critical data on the industry’s new lead-free solder compositions for design and reliability models. The database on these new materials and solder joints is still insufficient in comparison to Pbcontaining solders.
Lead-free solder alloys have been widely investigated in order to understand the microstructure property relations and mechanical testing have considerably high significance as they measure the comparable capacity of the solder joints and their components to withstand environmental loads. Despite the use of numerical modeling, simulations and computational analysis because direct measurements are not available, a large variance in reported overall shear behavior exists, even for identical solder composition and substrate combination. These reasons among others, were the driving force for the call for standardized experimental procedures that can be used to obtain stress strain data on actual interconnects and actual solder joints.
A new method was developed in order to use a possible different approach. This method is capable of producing miniature solder joints in large numbers and to test them rapidly. The results are analyzed in metallurgy terms and used to evaluate the mechanical-properties/microstructure relationship of lead-free alloys as an input for an experimental environmental/life-time-prediction