Moisture Sensitivity Level Classification and Floor Life Requirements
MSL classification dictates component allowable atmospheric exposure prior to reflow to prevent catastrophic internal delamination and joint failure.
JEDEC J-STD-020E
Reflow Classification
Industrial semiconductor testing establishes the moisture and reflow sensitivity levels used to identify components susceptible to moisture-induced stress. Under the protocol jedec j-std-020e, standardized test methods classify non-hermetic solid-state surface-mount devices. This classification enables manufacturers to assign appropriate floor-life limits and handling procedures for each component type.
Stress Evaluation
Evaluation methods involve preconditioning the devices with specific humidity and temperature exposures before subjecting them to simulated reflow profiles. The peak package temperature during reflow simulation depends on the volume and thickness of the package. Any internal cracking, delamination, or electrical failure observed after reflow dictates a lower sensitivity classification for the device.
Solid-state sensors undergo these rigorous evaluations to ensure they survive assembly lines without degradation.
Package Assessment
High-resolution scanning acoustic microscopy acts as the primary tool to detect internal delamination after testing. This non-destructive inspection reveals gaps between the plastic mold compound and the silicon die or leadframe. Comparing the pre-test and post-test acoustic images allows engineers to locate internal microcracks.
Standardised limits define the maximum allowable delamination area before a device is rejected.
Process Integration
Solder reflow ovens must be configured to match the peak temperatures established by these tests. Exceeding these thermal limits compromises the structural integrity of the packages.