This part of IEC 60749 establishes a standard procedure for determining the preconditioning of non-hermetic surface mount devices (SMDs) prior to reliability testing.
The test method defines the preconditioning flow for non-hermetic solid-state SMDs representative of a typical industry multiple solder reflow operation.
These SMDs are subjected to the appropriate preconditioning sequence described in this document prior to being submitted to specific in-house reliability testing (qualification and/or reliability monitoring) in order to evaluate long term reliability (impacted by soldering stress).
NOTE 1 Correlation of moisture-induced stress sensitivity conditions (or moisture sensitivity levels (MSL)) in accordance with IEC 60749-20 and this document and the actual reflow conditions used are dependent upon identical temperature measurement by both the semiconductor manufacturer and the board assembler. Therefore,the temperature at the top of the package on the hottest moisture sensitive SMD during assembly is monitored to ensure that it does not exceed the temperature at which the components are evaluated.
NOTE 2 For the purpose of this document, SMD is restricted to include only plastic-encapsulated SMDs and other packages made with moisture-permeable materials.
