This part of IEC 60749 defines the rapid change of temperature test method and the two-fluid-bath method. When both test methods are performed as part of a device qualification, results of air to air temperature cycling take priority over this two-fluid-bath test method. This test method may also be used, employing fewer cycles (e.g. 5 to 10 cycles), to test the effect of immersion in heated liquids that are used for the purpose of cleaning devices. This test is applicable to all semiconductor devices. It is considered destructive unless otherwise detailed in the relevant specification. In general, this rapid change of temperature and two-fluid bath method