IEC 60749-21:2025 PDF

IEC 60749-21:2025 establishes a standard procedure for determining the solderability of device package terminations that are intended to be joined to another surface using tin-lead (SnPb) or lead-free (Pb-free) solder for the attachment. This test method provides a procedure for “dip and look” solderability testing of through hole, axial and surface mount devices (SMDs) as well as an optional procedure for a board mounting solderability test for SMDs for the purpose of allowing simulation of the soldering process to be used in the device application. The test method also provides optional conditions for ageing. This test is considered destructive unless otherwise detailed in the relevant specification. NOTE 1 This test method does not assess the effect of thermal stresses which can occur during the soldering process. More details can be found in IEC 60749‑15 or IEC 60749‑20. NOTE 2 If a qualitative test method is preferred, the Wetting balance test method can be found in IEC 60068-2-69. This edition includes the following significant technical changes with respect to the previous edition: - revision to certain operating conditions in line with current working practices.