A Case Study of Nickel Dendritic Growth on Printed-Circuit Boards

Editors’ Choice—Challenges and Opportunities for Developing Electrochemical Biosensors with Commercialization Potential in the Point-of-Care Diagnostics Market

“…65,72,73 Immersion silver is directly electroplated from the electrolyte solution onto the copper layer, and lacks a nickel layer, making it weaker than immersion gold and requiring more care for long-term storage. 68 Industrial plating processes that use ENIG, ENEPIG, and hard gold introduce organic and inorganic impurities such as watersoluble and rosin-based flux residues, 74 copper traces, 75 and in rare cases, nickel 76 on electrodes, which could interfere with functionalization and consequently, the electroanalytical performance of biosensors manufactured using PCB technology. 40 It is crucial to reduce impurities introduced during plating by employing wet pretreatment or plasma cleaning techniques.…”