Resin / Rosin Free Solder Pastes and Fluxes

Since the beginning of the SMT process solder pastes have been developed on the basis of resins. Historically, development was focused only on the workability and solderability of the solder pastes. Due to the increased requirements of the manufactured final product, miniaturization of components and SMT coming closer to semiconductor i.e. SiP, current resin systems are not sufficient. Due to problems caused by residues in the SMT and Semiconductor applications a resin free solder paste and flux was developed. The main problems associated with conventional resin based systems are bondability, ICT, contamination in reflow ovens, compatibility with conformal coating and long term reliability in harsh working conditions. There is a further possibility that resin free systems improve the voiding performance in solder joints. The development step in the presentation is specific to the resin free solder paste. Additionally included are the properties of standards resin containing pastes and the resin free solder paste. Internal and external results have proved the product to be a drop in solution without the necessity of special equipment and process guidelines. Currently there are positive results in an automotive SMT application, DCB and wafer bumping