IEC 60068-2-20-2008 pdf Environmental testing – Part 2-20: Tests – Test T: Test methods for solderability and resistance to soldering heat of devices with leads

4.1.3 Initial measurements The specimens shall be visually examined and, if required by the relevant specification, electrically and mechanically checked. 4.1.4 Accelerated ageing If accelerated ageing is required by the relevant specification, one of the following procedures shall be adopted. At the end of the conditioning, the specimen shall be subjected to standard atmospheric conditions for testing for not less than 2 h and not more than 24 h. NOTE Terminations may be detached if the ageing temperature is higher than the component’s maximum operating or storage temperature, or if the component is likely to degrade considerably at 100。C in steam and thus affect the solderability in a manner which would not normally occur in natural ageing. 4.1.4.1 Ageing 1 The relevant specification shall indicate whether ageing 1a (1 h in steam) or ageing 1b (4 h in steam) is to be used. For these procedures the specimen is suspended, preferably with the termination vertical, with the area to be tested positioned 25 mm to 30 mm above the surface of boiling distilled water which is contained in a borosilicate glass or stainless steel vessel of suitable size (e.g.， a 2 litre beaker). The termination shall be not less than 10 mm from the walls of the vessel. The vessel shall be provided with a cover of like material consisting of one or more plates which are capable of covering approximately seven-eighths of the opening. A suitable method of suspending the specimens shall be devised; perforations or slots in the cover are permitted for this purpose. The specimen holder shall be non- metallic. The level of water shall be maintained by the addition of hot distilled water, added gradually in small quantities, so that the water will continue to boil vigorously; alternatively a reflux con- denser may be provided if desired. (See Figure A.1).