[DEMO] Safi-Tech Inc: Using Supercooled BiSnAg Solder to Create Full-Metal Conductive Interconnects for Heat-Sensitive Flexible-Hybrid Electronics

Supercooled liquid metal microcapsules are a disruptive technology that simplifies flexible-hybrid electronics (FHE) assembly. Forming full-metal interconnects of lead-free solder alloys without high-heat processes avoids thermal damage to components and materials or quality issues caused by coefficient of thermal expansion mismatch. This novel solder interconnect technology also overcomes the reliability and processing issues of conductive adhesives while returning conductive metal benefits to FHE products. The technology encapsulates RoHS compliant solder alloys inside a nanofilm that keeps the metal in a metastable supercooled liquid state at ambient temperatures. Metastability is maintained by a core-shell particle architecture. The thin oxide/organic shell can be mechanically broken or chemically dissolved to release the liquid metal, which then rapidly solidifies all without requiring heat. The feasibility of this new product is showcased in this video, where SAFI-Tech takes a solder paste containing BiSnAg supercooled liquid metal microcapsules, screen-prints the solder paste onto conductive pads, and then solders passive components at temperatures below the typical conductive adhesive curing temperature. SAFI-Tech’s new product offers a drop-in replacement solder paste formulation to take the heat out of FHE assembly.