IEC 60068-2-58:2015 outlines test Td, applicable to surface mounting devices (SMD). This standard provides procedures for determining the solderability and resistance to soldering heat of devices in applications using solder alloys, which are eutectic or near eutectic tin lead (Pb), or lead-free alloys. The procedures use either a solder bath or reflow method and are applicable only to specimens or products designed to withstand short term immersion in molten solder or limited exposure to reflow systems. The solder bath method is applicable to SMDs designed for flow soldering and SMDs designed for reflow soldering when the solder bath (dipping) method is appropriate. The reflow method is applicable to the SMD designed for reflow soldering, to determine the suitability of SMDs for reflow soldering and when the solder bath (dipping) method is not appropriate. This edition includes the following significant technical changes with respect to the previous edition: - the addition of Sn-Bi low temperature solder alloy; - the addition of several reflow test conditions in Table 7 - Resistance to soldering heat - Test conditions and severity, reflow method; - introduction of reflow test method for Test Td3: Dewetting and resistance to dissolution of metallization; - implementation of guidance for the choice of a test severity in Clause B.3.