Minimizing flux spatter during lead‐free reflow assembly

Purpose – The leaching of lead from electronic components in landfills to ground water is harmful to health and to the environment. Increasing concern over the use of lead in electronics manufacturing has led to legislation to restrict its use as a joining material. Consequently, significant recent research efforts have been geared to identification of suitable lead‐free solder pastes. Typically, lead‐free solder pastes contain a very active flux in an effort to improve wetting. These aggressive fluxes have the tendency to explode (or burst) and create flux spatter, causing many process problems with sensitive electronic components. The purpose of this paper is to propose solution procedures to minimize/eliminate these flux spatters, particularly, on gold fingers in memory modules when lead‐free solder pastes are used.Design/methodology/approach – Four no‐clean, lead‐free Sn‐Ag‐Cu (SAC) alloy‐based solder pastes consisting of four different flux systems from three different vendors were evaluated. Two typ...