RM 193: Why Post-Reflow Cleaning Is Becoming Mainstream Again

RM 193: Why Post-Reflow Cleaning Is Becoming Mainstream Again

From PCB Chat by PCEA

May 29, 2026 · 13 min · Episode 366

About this episode

This episode discusses the historical shift away from cleaning circuit assemblies post-soldering and the implications of that decision in modern electronics manufacturing.

For decades, cleaning circuit assemblies after soldering was not optional. It was standard practice across the electronics manufacturing industry. Then, almost overnight, that changed.In this episode of Reliability Matters, Mike Konrad takes you back to the origins of that shift. From the widespread use of CFC-based cleaning solvents to the global impact of the Montreal Protocol, this episode explains how environmental regulation led to the rapid adoption of no-clean flux and the removal of cleaning as a standard process step. But that decision came with assumptions.Assumptions based on larger components, wider spacing, and assemblies that were far more tolerant of residues than what we see today.As electronics evolved, so did the risk.Miniaturization, increased component density, and the expansion of electronics into harsh environments have dramatically reduced the tolerance for contamination. And when cleaning was removed, it wasn’t just flux that remained. It was the totality of residues introduced throughout the manufacturing process.This episode walks through how those residues, combined with moisture and electrical bias, can lead to electrochemical migration, including…

People in this episode

Guest: Mike Konrad

Topics covered

  • post-reflow cleaning
  • electronics manufacturing
  • environmental regulation
  • no-clean flux
  • electrochemical migration
  • residues in manufacturing

Keywords

  • cleaning
  • circuit assemblies
  • soldering
  • flux
  • contamination
  • miniaturization
  • electrical bias
  • dendritic growth

Mentioned in this episode

Organizations: Montreal Protocol, PCEA

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