The times when electronic devices where expensive, high-end items, that were being taken well care off, are far gone, and today electronic devices are to be regarded as consumables that can be expected to be brought practically anywhere on the planet's surface. This has created challenges to electronic manufacturers, as device reliability is extremely hard to predict before a product is launched, and even the slightest change from a sub-supplier could potentially lead to catastrophic changes in the corrosion behavior of the device. Electrochemical migration in electronics is a process that occurs when two metallic conductors under a potential bias are connected by an aqueous electrolyte, which commonly originates from condensation of humidity from the external environment. Prone metals, such as i.e. Sn, Cu, Ag, Au, Ni, Pb, Pd [1] can be dissolved at the anode and migrate under the electric field to the cathode where they can be deposited in their reduced metallic state. The result can be the growth of a dendrite acting as a metallic bridge from cathode to anode, which short-circuits the two conductors with potential failure of the electronic circuit as a consequence. The main metals that are directly exposed to the environment on a common Printed Circuit Board Assembly (PCBA) are tin and tin solders, making the corrosion mechanisms of these in electronics a very important subject. Electrochemical migration of tin is an extremely delicate process, where even the slightest impurities on the surface can have a profound impact on the migration behavior. For this reason, an extensive research has been conducted over the past years, in order to understand the migration mechanisms of tin and how it is affected by various parameters. A novel chip has been developed, where a nanoscale silicon nitride window allows making in-situ electron microscopy observations of electrochemical phenomena, such as electrochemical migration [2]. This presentation will give an overview of the chemical, electrochemical and thermodynamic mechanisms of the electrochemical migration of tin with examples from in-situ observation from optical and electron
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