Definition

Lead-free assembly is required for RoHS compliance and affects your PCB specification. The higher reflow temperatures (peak ~260°C vs ~230°C for leaded) require: high-Tg laminate (Tg ≥170°C), compatible surface finishes (ENIG, immersion silver, OSP, or lead-free HASL), and components rated for lead-free processing. When specifying a lead-free board, confirm your fabricator uses compatible surface finish and your components are MSL-rated for the higher temperatures. Lead-free solder (SAC305 or SAC387) has different wetting characteristics - discuss assembly requirements with your CM.