Ask Dr. Adam – Discovering Reliability Series, Part 1: What is SIR? with Dr. Mike Bixenman
Part 1: This episode of the Discovering Reliability series on Ask Dr. Adam features Magnalytix president Dr. Mike Bixenman, a leading expert on cleaning and electronics reliability, for a focused discussion on surface insulation resistance (SIR).
Dr. Bixenman explains SIR by breaking down surface, insulation, and resistance on printed circuit boards, highlighting how pad to pad spacing, flux and oxide residues, and real world climatic conditions such as heat, humidity, and moisture films influence leakage current and insulation loss.
They discuss how moisture dissolves ionic residues, enabling electrochemical processes that reduce surface resistance, and why SIR testing—run under controlled temperature, humidity, electrical bias, and time—is a powerful method for evaluating whether residues will cause reliability problems in end-use environments. The conversation shows how SIR data ties directly into objective evidence requirements, helping manufacturers understand when residues are truly benign and when they pose a risk to long-term electronics performance.