Cleanliness Assessment Correlation to Electronic Hardware Reliability

摘要

During the development of a specialized electronics assembly application process, the need for assessment of localized areas of residue entrapment (low standoff components),which are very susceptible to holding small but corrosive levels of processing materials even after repeated cleaning steps, became evident. Ion Chromatography bag extractions were found diminishing the sensitivity required to see the small pocket of residue below and on the component surface. These residues were easily solubilized but could not be detected if large areas were extracted so the use of a localized extraction tool to isolate the 0.1 in area was utilized on these samples and the residues were assessed to optimize the cleaning protocol. Through validation testing of functional hardware and an optimized cleaning protocol using localized cleanliness assessment techniques, the hardware successfully met product reliability substantiation requirements. Additional data analysis of localized extraction impact on residues from test hardware also correlated to the environmental assessment for clean and dirty hardware. It is not the cleanliness of the entire assembly that causes the failure but the pocket of contamination between two critical leads on the assembly that causes the failure.