Electronics assemblers are experiencing field performance problems due to processing and fabrication residues that are corrosive and conductive. These residues cause electromigration (dendritic growth) and electrical leakage failures (frequently classified as No Trouble Found – NTF returns) under typical operating conditions (humidity levels at 50% and higher).
Industry-standard process cleanliness tools and test methods (e.g.: IPC TM 650 2.3.25 Resistivity of Solvent Extract) can prove to be inadequate gauges of product cleanliness when testing today’s low solids and water-soluble fluxes. These tools can indicate false low levels and fail to identify if a residue is detrimentally corrosive and/or conductive. The need for a process assessment approach that identifies the contaminants and their concentrations has led to our development of this assessment package.
Foresite can determine if the residues from an electronics assembly process are detrimental and define (type and level of contaminant) the cleanliness required to build long-lasting, reliable hardware.
Our Approach to Process Assessment
To accurately assess your process, Foresite analyzes bare boards, assemblies (through various stages of the process – SMT-top, SMT-bottom, selective wave soldering, hand soldering, after cleaning), solder paste, flux and cored solder samples, along with water samples (if cleaner is used) from the final rinse. The analysis will include multiple locations on each board, specifically areas where residues are likely to become entrapped and/or circuit sensitivity is an issue. C3 and ion chromatography testing will be performed, assessing any residual processing contaminants.
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