IEC 60749-20:2008 provides a means of assessing the resistance to soldering heat of semiconductors packaged as plastic encapsulated surface mount devices (SMDs). This test is destructive. This second edition cancels and replaces the first edition published in 2002 and constitutes a technical revision. The main changes are as follows: - to reconcile certain classifications of IEC 60749-20 and those of IPC/JEDEC J-STD-020C; - reference IEC 60749-35 instead of Annex A of IEC 60749-20, Edition 1; - update for lead-free solder; - correct certain errors in the original Edition 1.