Corrosion in Electronics is the electrochemical degradation of metallic conductors in semiconductor packages and circuit boards — where metals (aluminum, copper, silver) react with moisture, oxygen, and contaminants (chlorides, sulfides) to form non-conductive corrosion products that consume the metal, creating open circuits, increased resistance, and eventual electrical failure, accelerated by temperature, humidity, electrical bias, and ionic contamination.

What Is Corrosion in Electronics?

• Definition: The chemical or electrochemical reaction between a metal and its environment that converts the metal into oxides, hydroxides, or salts — in electronics, this means aluminum bond pads dissolving into Al(OH)₃, copper traces oxidizing to Cu₂O/CuO, or silver migrating as Ag⁺ ions, all of which degrade electrical connectivity.
• Electrochemical Nature: Most electronics corrosion is electrochemical — requiring an anode (metal that dissolves), a cathode (where reduction occurs), an electrolyte (moisture film with dissolved ions), and an electrical connection between anode and cathode (the conductor itself or applied bias).
• Contamination Catalyst: Pure water is a poor electrolyte — corrosion requires dissolved ions (Cl⁻, Na⁺, SO₄²⁻) from flux residues, fingerprints, atmospheric pollutants, or packaging materials to create a conductive electrolyte that enables electrochemical reactions.
• Acceleration Factors: Corrosion rate increases with temperature (Arrhenius, 2× per 10°C), humidity (more electrolyte), contamination level (more ions), and applied voltage (stronger electrochemical driving force).

Why Corrosion Matters in Electronics

• Bond Pad Failure: Aluminum bond pads are particularly vulnerable — chloride ions penetrate the native oxide and attack the aluminum, creating "mouse bite" corrosion that thins and eventually severs the bond pad connection.
• Copper Trace Degradation: Copper traces corrode in humid environments with sulfur or chloride contamination — creating increased resistance and eventual open circuits in critical signal and power paths.
• Silver Migration: Silver is the most mobile common metal under bias — silver ions dissolve at the anode and plate out as dendrites at the cathode, causing short circuits between adjacent conductors.
• Field Failure Cost: Corrosion failures often occur after months or years of field operation — making them difficult to reproduce and expensive to diagnose, with warranty and recall costs far exceeding prevention costs.

Corrosion Types in Electronics

Corrosion in electronics is the silent reliability killer that degrades metallic conductors over time — driven by the electrochemical interaction of metals with moisture and contaminants, requiring comprehensive prevention through passivation, cleanliness, conformal coating, and environmental control to protect the metallic interconnects that carry every signal and power connection in semiconductor packages and circuit boards.