This section of IEC 61189 is utilized to evaluate the changes in the surface insulation resistance of a pre-selected material set on a representative test coupon, and it quantifies the detrimental effects of improperly used materials and processes that can lead to decreased electrical resistance.
An assembly process involves numerous different process materials, including solder flux, solder paste, solder wire, underfill materials, adhesives, staking compounds, temporary masking materials, cleaning solvents, conformal coatings, and more. The test employs two different test conditions: 85 °C and 85% relative humidity (RH), which is preferred for processes that include cleaning, or 40 °C and 90% relative humidity (RH), which is preferred for processes where no cleaning is involved.
NOTE: 40 °C and 93% RH can be used as an alternative to 40 °C and 90% RH. Additional information is provided in 5.4 and A.5.2.
Testing is material (set) and process/equipment specific. Qualifications are to be performed using the production intent equipment, processes, and materials.
