shipping and using moisture-sensitive surface-mount devices. It de nes methods and outlines procedures to use to avoid damage from moisture absorption and exposure to re ow temperatures that can result in yield and reliability degradation. The standard helps end users achieve safe and damage-free re ow with the dry packing process.
Both of the industry standards classify moisture sensitivity levels (MSL). Each level is expressed numerically, with the MSL number increasing with the vulnerability of the package to popcorn cracking. For instance, MSL 1 refers to electronic devices that are immune to popcorn cracking regardless of exposure to moisture.
On the other hand, MSL 6 devices are most prone to moisture- induced fracture and have an extremely short oor life. The oor life of a part is the amount of time that it can be exposed to the environment and still be considered safe to re ow.