Meaning
Quality standards for electronics manufacturing establish the classification levels for moisture-sensitive plastic surface mount packages during reflow soldering. The standard known as j-std-020 provides guidelines that help factory operators identify which components are susceptible to moisture-induced damage. It defines the maximum exposure times that devices can withstand before being mounted and soldered.
Reflow Profile
Components absorb ambient moisture which can rapidly expand and cause internal delamination or package cracking during the high temperatures of reflow soldering. To determine the sensitivity levels, test samples are baked dry, subjected to specific moisture preconditioning, and passed through a reflow oven simulation. The resulting defects are analyzed using acoustic microscopy and visual inspection to determine if the package can withstand the thermal stress of lead-free soldering processes.
Moisture Classification
Reflow profiles specified in the standard range from 245 to 260 degrees Celsius depending on the volume and thickness of the package. Heavier packages require lower peak temperatures to prevent damage to the internal silicon die and leadframe interface.
Industrial Execution
Factory operations in Shenzhen and Suzhou print moisture-sensitive labels on component dry bags based on these levels. Operators must track the floor life of opened bags to prevent defects during board assembly.
