This part of IEC 60068 outlines test Td, applicable to surface mounting devices (SMD), which are intended to mount on substrates. This standard provides the standard procedures for solder alloys containing lead (Pb) and for lead-free solder alloys. This standard provides standard procedures for determining the solderability and resistance of soldering heat to lead-free solder alloys. This standard provides standard procedures for determining the solderability, dissolution of metallization and resistance of soldering heat to solder alloys which are eutectic or near eutectic tin lead solders.